DIY_EFI Digest Friday, 22 August 1997 Volume 02 : Number 284 In this issue: Re: Holley efi (model 502 analog system) Re: pintle vs. disc injector types injectors: dimensions and types; [none] ProJection Fuel Pump for Sale Re: injectors: dimensions and types; Re: rising rate fuel pressure regulators Graphs Re: Holley efi (model 502 analog system) Re: ProJection Fuel Pump for Sale RE: DIY_EFI Digest V2 #283 Air mass meter for sale Injector control question Re: TPI Questions ecm for sale Re: Injector control question Re: Injector control question Re: injectors: dimensions and types; Re: ecm for sale Re: ACCEL DFI users, Unite! Re: For REALLY good injection, check this out Re: TPI Questions Re: injectors: dimensions and types; BOSCH stuff Re: TPI Questions Re: TPI Questions See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Ken-Arne Jensen Date: Fri, 22 Aug 1997 11:37:10 +0200 (METDST) Subject: Re: Holley efi (model 502 analog system) Hi Tom Aug 22 > Here are some notes about the way the Holley ProJection system > works. I'm slowly reverse-engineering it so that I'm not > left stranded (like I am right now ..... with an injector > that doesn't work and don't know where to get another $69 from > Super Shops). >=20 > I've heard that a standard Bosch injector works but I don't > know if that's true or what part number. If someone knows any > more info on this, please let me know (I need one yesterday !!). >=20 > The injector measures 1.8 ohms resistance (well, the other one > measured 7.4 ohms, 332 ohms, 1.5 ohms, open circuit, etc, etc) I had the same problem when I got my Holley 502-1 system some years ago. One of the injectors wouldn't fire at all, and had different readings when I tried to measure the resistance with a multimeter. You should check the soldering on the connecting pins on both=20 injectors. The connecting pins on the injector have a small (copper I presume) wire inside of a metallic tube (~1 mm). The fabric soldering on one connector pin didn't have good contact with = the=20 wire inside. So the fix was simply to use a small file on the tip=20 of the connector pin tube, and resolder each pin.=20 I did this for all connector pins just to be sure :-).=20 This was back in 1993, and the injectors have worked fine since. I also had a stuck open injector later on, but that was due to a defect ECU (that Holley replaced without charge). It was a quite amazing experience :-( , beleive me. You drive normally and suddendly one = injector stick open, the engine bogs and finally stops, and when you switch off = the ignition and check under the hood, it is gas everywhere. I later found the reason, Because the injectors on a TBI are placed = above the throttle plates, and you let off the foot when the engine dies, but wait a bit before you switch of the igition (and the pump), the gas fills up and float around on a hot engine. I think I did this test run without an air filter too, and this helped of course :-). //// Ken-Arne Jensen // E-Mail: ken@xxx.no = = / /// Computer Science Department // URL: http://www.cs.uit.no/~ken = = // // University of Troms=F8 // Phone: +47-776-44042 = = /// / N-9000 Troms=F8, NORWAY // Fax: 44054 = (barcode=3D"ken@xxx.ui") //// ------------------------------ From: Clint Corbin Date: Fri, 22 Aug 1997 03:46:19 -0600 Subject: Re: pintle vs. disc injector types At 05:57 PM 8/21/97 -0700, you wrote: >A follow-up to this, if I might. In the turbocharged applications I'm >familiar with, a 1:1 fuel pressure regulator is used, which increases >fuel rail pressure in direct proportion to the increase in boost >pressure. What I'm wondering is, if the presssure downstream of the >injector has increased by the same amount as the pressure upstream of >the injector, won't this affect the predicted outcome? And if it will, Michael, As far as the injector is concerned with, all that matters is the pressure differential between the fuel side of the injector and the intake manifold. If you increased the manifold pressure by 100psi and also increase the fuel rail pressure by the same 100psi, you should have the exact same flow rate as before. All you are doing when you tie fuel rail pressure to boost pressure is preventing the flow rate for a given duty cycle from falling off as the boost pressure increases. Software would still have to take care of the increased fuel demand required by the boost pressure. >Best, > >Michael McBroom Clint Corbin ccorbin@xxx.com ccorbin@xxx.com ------------------------------ From: Rich Mauruschat Date: Fri, 22 Aug 1997 08:53:44 +0100 Subject: injectors: dimensions and types; Kerrie, How much detailed dimensional injector info. do you need? I have a scale drawing which I produced for my own purposes (to build throttle bodies/fuel rail/modify inlet manifold) which I could easily dimension. The drawing is generated from my own measurements but I think it's pretty accurate. The injectors from the V6 are probably 'disc' nozzle type as opposed to pintle nozzle; they are supposed to provide better atomisation and more significantly, are more resistant to gum build-up in the nozzle which is especially aggravated by unleaded fuel. The only fitment of disc nozzle injectors that I know of personally is on late model Range Rover, 3.9L/4.6L V8 in the UK, 4.0L V8 in the US. These have the appearance of having 4 nozzles set into a large metal ring. I'm not sure what the spray pattern looks like compared with a pintle nozzle - anyone have any comments here? There are instances of injectors used on 4-valve heads which deliberately spray 2 jets in an effort to direct the fuel onto the inlet valves, either side of the port split. Brad Sheridan also asks about disc injectors; Brad, I would be interested in your findings on the subject of pintle/disc nozzle comparisons. Cheers Rich. ------------------------------ From: dusher@xxx.com Date: Fri, 22 Aug 1997 12:47:45 BST Subject: [none] Hi all, Does any have some plots of say vacuum vs throttle pos and engine speed vs enjection pulse width.? Also any ideas on how to works the most economic speed?. Just things i think whilst driving along (as you do ;-). If anyone can please e-mail via dave@xxx. - -- ------------------------------ From: "Robert Gallant" Date: Fri, 22 Aug 97 08:17:55 EDT Subject: ProJection Fuel Pump for Sale I have a brand new (unopened), Holley 512-103 ProJection fuel pump, inlet filter, and wire harness for sale $70. This is the pump for the larger two bbl analog ProJection. Rob gallant@xxx.mil ------------------------------ From: Kerrie.Thornton@xxx.uk Date: Fri, 22 Aug 1997 13:21:18 +0100 Subject: Re: injectors: dimensions and types; Kerrie Thornton@ISL 22/08/97 13:21 Rich, I am going to use the info for making some throttle bodies, so what ever you have would be great. The injectors came out of a manifold bought at an auction for ?5. The part no's showed the background as the V6 omega. It was bought only a short time after the V6 went into production so we are not sure of its history but it is brand new. The injector appears to be identical to any other bosch injector that I have seen apart from the 4 holes in the end. Kerrie. ------------------------------ From: jon hanson Date: Fri, 22 Aug 1997 14:33:25 +0100 Subject: Re: rising rate fuel pressure regulators Michael McBroom wrote >Boy, did my equations get fouled up in the word-wrap process. Let me >try this again. For a turbocharged application in which a proportional >fuel pressure regulator is used, then it seems to me that one cannot use >the equation: > > P2 > Q2 = Q1 * (----)^0.5 > P1 > >to determine flow. It seems that instead one must use the ratio of the >differences between fuel rail pressures and intake pressures in order to >determine new flow rates, since fuel rail pressure increases with >boost. The way I see it, the following equation would have to be used: > > P2 - (atmospheric + boost) > Q2 = Q1 x (----------------------------)^0.5 > (P1 - atmospheric) > >where: P1 = fuel rail pressure + atmospheric pressure > P2 = P1 + (boost * fpr ratio) > >EG #1: using a 1:1 fuel pressure regulator > >Given: 1:1 fpr > 0.8 bar boost > Q1 = 300ml/min > P1 = 3 bar + 1 bar (rail pressure + atmospheric pressure) > P2 = P1 + (boost * fpr ratio) > > ([3 + 1] + [0.8 * 1]) - (1 + 0.8) >Q2 = 300 x (-----------------------------------)^0.5 > ([3 + 1] - 1) > > = 300ml/min = Q1 > > >EG #2: using a 2:1 rising rate fuel pressure regulator > >Given: all of the above, but with a 2:1 rrfpr > > ([3 + 1] + [0.8 * 2]) - (1 + 0.8) > Q2 = 300 x (------------------------------------)^0.5 > ([3 + 1] - 1) > > = 338ml/min > > >This still seems to be the right approach to me. If I've committed an >egregious error anywhere, though, please let me know. > >-- >Best, > >Michael McBroom Here's my 2c worth I installed an fse rising rate fpr to overcome a problem of running my injectors at too high a duty cycle at highest revs and WOT. the adds for fse say fp increases 1.7 parts for every part of air I took this to mean it is a 1.7 : 1 fp reg(simpler if they just said so) The Engine is NON TURBO but the same argument applies I set fuel pressure at idle to 2.7 bar (at which the nippondenso injectors deliver 20.55 lbs/hr) my MAP reading at idle is 0.25 bar. MAP at WOT is 1 bar so there is an increase of pressure 0f 0.75 bar in opening the throttle from idle to WOT. if it was a 1:1 reg then the fp would have risen by 0.75 bar to maintain a const 2.7 bar accross the injectors.Since it is a 1.7 : 1 fpr the EXTRA increase in fp is (0.7 * 0.75)= 0.525 bar so P new = 2.7 + 0.525 = 3.225 bar P old = 2.7 new flow rate at WOT = 20.55 (old flow rate) * sqrt(3.225/2.7) = 22.46 lbs/hr the flow rate at idle remains 20.55 lbs/hr This is the same end result as Michaels formula so I agree with him. I'm a begginer so if this is all wrong I would appreciate being pointed in the right direction Regards Jon Hanson. ------------------------------ From: dusher@xxx.com Date: Fri, 22 Aug 1997 13:52:30 BST Subject: Graphs Hi all, Does any have some plots of say vacuum vs throttle pos and engine speed vs enjection pulse width.? Also any ideas on how to works the most economic speed?. Just things i think whilst driving along (as you do ;-). If anyone can please e-mail via dave@xxx. - -- ------------------------------ From: Tom Cloud Date: Fri, 22 Aug 1997 08:13:34 -0500 Subject: Re: Holley efi (model 502 analog system) I wrote: >> I've heard that a standard Bosch injector works but I don't >> know if that's true or what part number. If someone knows any >> more info on this, please let me know (I need one yesterday !!). >> >> The injector measures 1.8 ohms resistance (well, the other one >> measured 7.4 ohms, 332 ohms, 1.5 ohms, open circuit, etc, etc) and Ken replied: >I had the same problem when I got my Holley 502-1 system some years ago. >One of the injectors wouldn't fire at all, and had different readings >when I tried to measure the resistance with a multimeter. > >You should check the soldering on the connecting pins on both >injectors. The connecting pins on the injector have a >small (copper I presume) wire inside of a metallic tube (~1 mm). >The fabric soldering on one connector pin didn't have good contact with the >wire inside. So the fix was simply to use a small file on the tip >of the connector pin tube, and resolder each pin. >I did this for all connector pins just to be sure :-). >This was back in 1993, and the injectors have worked fine since. > >I also had a stuck open injector later on, but that was due to a >defect ECU (that Holley replaced without charge). It was a quite amazing >experience :-( , beleive me. You drive normally and suddendly one injector >stick open, the engine bogs and finally stops, and when you switch off the >ignition and check under the hood, it is gas everywhere. >I later found the reason, Because the injectors on a TBI are placed above >the throttle plates, and you let off the foot when the engine >dies, but wait a bit before you switch of the igition (and the pump), >the gas fills up and float around on a hot engine. I think I did this >test run without an air filter too, and this helped of course :-). > > >//// Ken-Arne Jensen dang it Ken, I thought I was real smart last night when I examined the injector under a magnifier and determined that there was a hollow tube (actually .062" or about 1/16" -- I'm still "American" ;-) ..... with a small wire sticking out the end. When I put my ohmmeter on the outer tube and jiggled the inner wire, I determined that it was making intermittent contact -- so I soldered them together. Did both injectors (just like you 8-) Am driving the beast this morning -- actually seems to be running better than ever. I think it really is, not my imagination -- think the intermittent has been bedeviling me for some time. I hope that's why I've never been able to get it working consistently. BTW, do you still have the 502? Tom Cloud I took an IQ test and the results were negative ------------------------------ From: Tom Cloud Date: Fri, 22 Aug 1997 08:13:35 -0500 Subject: Re: ProJection Fuel Pump for Sale >I have a brand new (unopened), Holley 512-103 ProJection fuel pump, inlet >filter, and wire harness for sale $70. This is the pump for the larger two bbl >analog ProJection. > > >Rob Rob, why don't you post that to the Holley web site ? Tom Cloud I took an IQ test and the results were negative ------------------------------ From: Greg Woods Date: Fri, 22 Aug 1997 09:12:00 -0500 Subject: RE: DIY_EFI Digest V2 #283 > > ** CS453 (TO-220) [5 pins] CS is usually a harris part. I searched their web page and couldn't find any info though:( I don't know what it is...?? > > ** LM2917 (8-pin DIP) frequency to voltage convertor, from national semiconductor see http://www.national.com/pf/LM/LM2917.html (.pdf data sheet is available from websight) > ** MJE-295 (TO-220) [has an "ST" logo] I think it's a motorola bipolar power transistor. but I could be wrong... > ** MTP-305 (TO-220) [has an "ST" logo] I think it's a motorola power mosfet? but again, I could be wrong... > ** RC4200N (8-pin DIP) multiplier/divider, from raytheon. check out: http://www.raytheon.com/sd/RC4200.html hope this helps you out tom! Greg Woods gwoods@xxx.com austin, tx ------------------------------ From: verde@xxx.) Date: Fri, 22 Aug 1997 07:30:17 -0700 (PDT) Subject: Air mass meter for sale I have an Air Mass Meter from a Nissan V6. I'm sure you all know this but it measures the air mass by heatingtwo wires in the air flow instead of air flow with a door opening. If anyone is interested e-mail me direct at verde@xxx.com Thanx Jason G. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> http://rogue.northwest.com/~verde <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< ------------------------------ From: Tom Cloud Date: Fri, 22 Aug 1997 09:39:14 -0500 Subject: Injector control question In examining my Holley ProJection (model 502 analog) I find that the pulse width to the injectors is a constant (approximate) 1 millisecond with the rep rate varying by RPM, TPS and (maybe) temp. I'm sure this question has been answered in various ways before, but it's popped to the fore for me and I'd like to hear some of your thoughts on it ... Seems to me there's two ways to control an injector .. 1 - run a constant rep rate (PRR) and vary the pulse width (PW) 2 - run a constant PW and vary the PRR 3 - all of the above ;-) (I know, I said two ... 8-) Insert comments here (please) ...... NEXT ... Some time back (few weeks ago) there was a question about building a meter to monitor the PW of injectors and I replied that this was just a tachometer -- i.e. a duty cycle monitor -- where 100% would make the meter go full scale (or to "100" on a DPM) -- this should track duty cycle rather nicely -- as long as the rep rate doesn't fall so low the meter starts "bouncing". But then, someone pointed out that I was a dunce and that duty cycle and pulse width were different animicules (and he is certainly right -- on both counts ;-) Now, the question ..... why do you (whoever you are) want to know pulse width when fuel delivery is predicated on duty cycle (i.e. pulse width vs. rep rate) ???? Measuring the pulse width is do-able, but certainly more complicated that putting your VOM on the injector line and marking the 12 volt mark as 100% (I know, I know, it's slightly more tedious than that -- put a single transistor saturated switch in to condition the injector pulse to a 0-12 volt swing and **then** do it!!). ++++++++++++++ well, that was kinda two questions .... I guess 8^) Tom Cloud Ever stop to think .... and forget to start again ?? ------------------------------ From: bwmsbldr@xxx.com (Bill Williams) Date: Fri, 22 Aug 1997 10:54:34 EDT Subject: Re: TPI Questions Bear in mind that water or water/methanol injection will exert a powerful cooling effect on the mixture rather than merely diluting the mixture with hot, inert, gasses. Bill in Boulder "Engineering as an Art Form" ------------------------------ From: "Andrew F. Gunnesch" Date: Fri, 22 Aug 1997 11:17:54 -0400 Subject: ecm for sale i was having mail problems a few weeks ago when i originally tried to send this, so perhaps it never made it out (didn't see it anyhow) I have an aftermarket ECM replacement for GM 1227748 that I no longer have a need for. It was plugged in and tested, but wasn't run. Please let me know if you're interested andrew ------------------------------ From: Bruce Bowling Date: Fri, 22 Aug 1997 11:27:41 EDT Subject: Re: Injector control question > > In examining my Holley ProJection (model 502 analog) I find > that the pulse width to the injectors is a constant (approximate) > 1 millisecond with the rep rate varying by RPM, TPS and (maybe) > temp. > > I'm sure this question has been answered in various ways > before, but it's popped to the fore for me and I'd like to > hear some of your thoughts on it ... > > Seems to me there's two ways to control an injector .. > > 1 - run a constant rep rate (PRR) and vary the pulse width (PW) > > 2 - run a constant PW and vary the PRR > > 3 - all of the above ;-) (I know, I said two ... 8-) > Yes, you can run either (1) or (2). > > > NEXT ... > > Some time back (few weeks ago) there was a question > about building a meter to monitor the PW of injectors > About a year ago, I made such a meter out of a PIC 16C56 chip. The circuit was incredibly simple: I took a 4N25 optoisolator, with the LED driven across the injector. The transistor emitter was grounded, and collector pulled up high thru a 1K resistor. This junction was put into one of the PIC pins, configured as an input. Another pin, config. as an output, directly drove a 1 milliamp analog meter movement (other end grounded). I timed the input pulsewidth, and generated a PWM signal which drove the meter movement. The meter works well if the injector driver is a saturated type, and works most of the time for peak/hold drivers (the switch from the peak current to the hold current sometimes causes a short spike, which the PIC inteprets as an end-of-pulse). One day, I will fix this effect in the software, but it is low on my list. I know, I know - everybody wants to see the software. For free...... I think this is the latest version (I know the latest is on my home PC): - -----snip-------------snip------------snip--------------------------- TITLE "PulseWidth Meter" LIST P = 16C56 ERRORLEVEL 0 ; ;Define Equates: ; PIC56 EQU H'03FF' ;****************************************************************************** ; ;External Ossc. used = 3.579545Mhz. Prescaler of 8 used, which gives a ;??.?? microSec increment of the RTCC. If RTCC is intially loaded with 245, ;it would overflow to 0 in 0.098337 milliSecs. ; MSEC01 EQU D'245' FULLSCAL EQU D'200' FULLSM1 EQU D'199' ; ; ; Program: pulsewidth.ASM ; Revision Date: ; 12-18-96 B. Bowling ; ;****************************************************************************** ; ; ;Define RAM Locations: INDF EQU 0 RTCC EQU 1 PC EQU 2 STATUS EQU 3 FSR EQU 4 PORT_A EQU 5 PORT_B EQU 6 ; F EQU 1 C EQU 0 DC EQU 1 Z EQU 2 ; ; ;Define Real Time Mode regs (RTM) MMTMR EQU 8 ;0.1 millisecond timer variable. MSTMR EQU 9 ;Millisec. Timer. SUTMR EQU 0A ;0.1 seconds timer. STMR EQU 0B ;Sec. Timer. MTMR EQU 0C ;Min. Timer. ERRRR EQU H'15' ;Temporary Var. ROOL EQU H'11' ;Roll over timer for PWM. PWM EQU H'12' ;Actual PWM variable. SAMPLIN EQU H'13' ;Flag for sampling mode 0 = no, 1 = yes. SAMPTIME EQU H'14' ;Measured pulse width in 0.1 microsec resolution. ; ; ; ========================================================= ; <-- S T A R T O F E X E C U T I O N H E R E --> ; ========================================================= ; ORG 0 START CALL INIT_CLK ;Initialize clock and variables. ; ; Main loop section. ; Always go back to here each iteration......... ; Master timer loop. TIMER_LOOP ; MOVF RTCC,W ;See if RTCC = 0. BTFSS STATUS,Z ;if zero flag set then skip one instruction, GOTO TIMER_LOOP ;otherwise loop to TIMER_LOOP. ; MOVLW MSEC01 ;RTCC = 0.1 msec. MOVWF RTCC ;by setting the RTCC to this value each time INCF MMTMR,f ;Inc 0.1 millisecond variable (has occured here). ; ; PWM mode here ; INCF ROOL,f ;rolling timer variable, used to time PWM. ; MOVLW FULLSCAL ;check for ROOL exceeding FULSCAL value SUBWF ROOL,W ; by subtraction. BTFSC STATUS,Z CLRF ROOL ;reset ROOL, because we are at fullscale. ; MOVF ROOL,W ;Check if the ROOL timer variable is zero, BTFSS STATUS,Z ; if it is, jump over one instruction. GOTO BASH ;It is not zero, go check if ROOL is greater than PWM. MOVLW H'FF' ;make port pin high, start of timer. MOVWF PORT_A ;output this to the pin. ; BASH MOVF ROOL,W ;Get the current value of ROOL. SUBWF PWM,W ;Check if it is greater than PWM variable. BTFSS STATUS,Z GOTO PULSE_CHECK ;no, so go to next part of code. MOVLW H'00' ;It is, so output a low to the PWM pin. MOVWF PORT_A ; **************************************************************** ; *** Pulse Check Occurs Here *** ; **************************************************************** PULSE_CHECK MOVLW B'00000001' ;Pin 8 of port B is input for pulse, ANDWF PORT_B,W ; get only this pin value. BTFSS STATUS,Z ;Skip over next instruction if the carry bit is clear..... GOTO PIN_HIGH ; go here is pin is high. GOTO PIN_LOW ; ;Pin is low -> start of sampling PIN_LOW INCF SAMPTIME,f ;Increment sampling time (will zero out later if need be). ; MOVLW FULLSCAL ;Check if samptime is greater than fullscale SUBWF SAMPTIME,W BC PTL ;It is, so branch to ptl ; MOVF SAMPLIN,W ;get the sample mode flag. BTFSS STATUS,Z ;if zero, then not sampling yet, and need to turn on mode and reset time GOTO MILLI_HAPPY ; continue on to milliseconds updating. CLRF SAMPTIME ;reset the sample time (must be first time high). INCF SAMPLIN,f ;set sample flag to 1, indicating we are now sampling. GOTO MILLI_HAPPY ; continue on to milliseconds updating. ; PTL INCF ERRRR ;error occured GOTO MILLI_HAPPY ; ;Pin is high -> end of sampling -- check is pulse is too long PIN_HIGH MOVLW D'01' ;Check if we are in sampling mode via. SAMPLIN=1. SUBWF SAMPLIN,W BTFSS STATUS,Z ;Jump one instruction if we are in sampling mode (=1). GOTO MILLI_HAPPY ;No, just jump over all other tests. ; CLRF SAMPLIN ;First, clear out SAMPLIN flag to allow next pulse detection. MOVF ERRRR,W BTFSS STATUS,Z GOTO TOOLONG ;Error occured somewhere. ; MOVLW FULLSCAL ;Check if we have pulse longer than FULLSCAL SUBWF SAMPTIME,W ; which is too long to display. BC TOOLONG ;We cannot display this, too long. ; MOVF SAMPTIME,W ;Now we can update the PWM variable MOVWF PWM ; with the value of SAMPTIME. GOTO MILLI_HAPPY ; TOOLONG MOVF FULLSM1,W MOVWF PWM CLRF ERRRR ; CLRF PWM ;Zero out meter, pulse was too long. GOTO MILLI_HAPPY ; ; ; MILLI_HAPPY ; MORE_MILLI MOVLW D'10' ;Milliseconds checker. SUBWF MMTMR,W ;Can I update milliseconds. BTFSS STATUS,Z ;check the zero bit. GOTO TIMER_LOOP ;Check the loop again. ; CLRF MMTMR INCF MSTMR,f ; GOTO TIMER_LOOP ; ; Now check for 0.1 second update. MOVLW D'100' SUBWF MSTMR,W BTFSS STATUS,Z GOTO TIMER_LOOP CLRF MSTMR INCF SUTMR,f ; ; Now check for seconds update MOVLW D'10' ; now check if 0.1 rolls SUBWF SUTMR,W BTFSS STATUS,Z GOTO TIMER_LOOP ; CLRF SUTMR INCF STMR,f ;Increment the seconds timer ; Now check for seconds rollover MOVLW D'10' SUBWF STMR,W ;Can I update milliseconds BTFSS STATUS,Z ;check the carry bit GOTO PLOP_DIGIT ;Check the loop again CLRF STMR ; ; PLOP_DIGIT GOTO TIMER_LOOP ;LOOP ; ; ;This routine sets up ports A,B,C and the internal ;real time clock counter. INIT_CLK MOVLW B'00000000' ;MAKE ACTIVE low MOVWF PORT_A ; / MOVLW B'00000000' ;SET PORT A AS OUTPUTS TRIS PORT_A ; MOVLW B'00000000' ;SET LEVELS low MOVWF PORT_B ; / MOVLW B'00000001' ;SET PORT B AS OUTPUTS, RB7 as input TRIS PORT_B ; ; CLRWDT ;Must clear watchdog timer first MOVLW B'00000010' ;SET UP PRESCALER OPTION ; / ; MOVLW MSEC01 ;RTCC = 0.1 mSEC MOVWF RTCC CLRF MMTMR ;Clear 0.1 milliseconds CLRF MSTMR ;CLEAR MSTMR CLRF SUTMR CLRF STMR ; & SEC TMR CLRF MTMR ;& MINUTES CLRF SAMPLIN CLRF SAMPTIME CLRF ERRRR MOVLW FULLSCAL MOVWF PWM RETLW 0 ; ; ; ; ; ----------> System reset section <--------------- ; ORG PIC56 SYS_RESET GOTO START ; END - -----snip-----snip----snip--------------------------------- - - Bruce - -- - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- Bruce A. Bowling Staff Scientist Thomas Jefferson National Accelerator Facility 12000 Jefferson Ave - Newport News, VA 23606 (804) 249-7240 bowling@xxx.gov/~bowling - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- ------------------------------ From: Tom Cloud Date: Fri, 22 Aug 1997 11:27:52 -0500 Subject: Re: Injector control question I wrote: >> In examining my Holley ProJection (model 502 analog) I find >> that the pulse width to the injectors is a constant (approximate) [ snip ] >> NEXT ... >> >> Some time back (few weeks ago) there was a question >> about building a meter to monitor the PW of injectors and Bruce replied: >About a year ago, I made such a meter out of a PIC 16C56 chip but Bruce, you didn't address my primary query -- that being: "why does one want to know the PW when it's the duty cycle that's impotent (regardless of whether one uses fixed PRR/var. PW or fixed PW/var. PRR) ?? Am I incorrect about that ?? I recognize that there's going to be errors in fuel delivery calcs at the opening and closing of the injector, so short pulses would deliver less fuel/time than long pulses and this would imply that a simple duty cycle measurement would have some inherent errors, but I'd think they'd be minimal. IOW, seems that duty cycle is what you want to measure, not PW ???? Tom Cloud Ever stop to think .... and forget to start again ?? ------------------------------ From: sheridan@xxx.com (Brad Sheridan) Date: Fri, 22 Aug 1997 08:16:11 +0100 Subject: Re: injectors: dimensions and types; >Kerrie, >How much detailed dimensional injector info. do you need? I have a scale >drawing which I produced for my own purposes (to build throttle bodies/fuel >rail/modify inlet manifold) which I could easily dimension. The drawing is >generated from my own measurements but I think it's pretty accurate. >The injectors from the V6 are probably 'disc' nozzle type as opposed to >pintle nozzle; they are supposed to provide better atomisation and more >significantly, are more resistant to gum build-up in the nozzle which is >especially aggravated by unleaded fuel. > > >Brad Sheridan also asks about disc injectors; Brad, I would be interested >in your findings on the subject of pintle/disc nozzle comparisons. I don't have too much yet, but I'll pass along what I do find. The reason I'm asking is that The Triumph T595 motorcycle comes standard with the disc type injectors. I've heard to avoid disc type injectors, but I want to know more about why before I go switching them out. All I've heard so far is that the disc type injectors aren't nearly as linear. I think Lucas is the manufacturer of the disc injectors. Thanks, Brad ------------------------------ From: Mark Taschek Date: Fri, 22 Aug 97 12:31:08 CDT Subject: Re: ecm for sale > > i was having mail problems a few weeks ago when i originally > tried to send this, so perhaps it never made it out (didn't > see it anyhow) > > I have an aftermarket ECM replacement for GM 1227748 that I > no longer have a need for. It was plugged in and tested, > but wasn't run. > > Please let me know if you're interested > > andrew > /////////////// Andrew what is lowest you will take for it.......... you can email me at mtaschek@xxx.com ------------------------------ From: Gerald San Agustin Date: Wed, 20 Aug 1997 21:39:28 -0700 Subject: Re: ACCEL DFI users, Unite! I haven't been active on this mailing list , but since the topic of Accel DFI came up, I'd like to ask anyone who has this setup if they can send me a copy of a actual file from any car. I have a copy of CalMap but can't do a thing without a fuel map file. I'm currently using an Electromotive TEC unit but seriously considering trying a DFI system. I just want to see what the maps look like before I decide to switchover. Gerald San Agustin 88 MR2 Twincharger ------------------------------ From: Terry Martin Date: Fri, 22 Aug 1997 10:53:51 -0700 Subject: Re: For REALLY good injection, check this out Frank Piccolo wrote: > I thought he might be getting energy from the reaction of the Earth's > magnetic field and the colaps of the units own field collapsing. Then > it would not be classified as a perpetual motion machine. The thing doesn't have to be a perpetual motion machine to be patently un-patentable, it has to be useful. I built a crystal radio when I was 8 that induced enough "free" energy to drive an earphone. That's about what you could get out of this thing, or possibly even drive a compass, and that's already been done. More to the point, I still want to know how much this guy's hydro bill is, since he has "virtually unlimited free energy" at his disposal. His problem is he's just plain stupid. Ignorance is acceptable because it can be remedied, stupidity has no excuse. > But since the movement knows best......How much was the pentagon > paying for a hammers again. Some of my best ideas occur when I'm having a movement, or when I'm hammered for that matter. I fiqure it's probably the universe that "know's best", since the "laws" that describe it are arranged in such a way that there is no penalty for "breaking" one because it's impossible to do so, even accidently by a stupid person. I'd better mention really good injectors here or I'll be hissed at. :-) I still think compressing part of the air charge into the injector stream is an idea with merit. It would act the same as anything else when decompressed (injected), and cool the combustion chamber. If it was done just at the overlap point of exhaust and intake, the cylinder would not heat the intake charge as much by virtue of residual heat from the power stroke (exhaust), and would increase the volumetric efficiency of the engine. It would also serve to better atomize the injector stream. No? Terry ------------------------------ From: Terry Martin Date: Fri, 22 Aug 1997 11:10:08 -0700 Subject: Re: TPI Questions Bill Williams wrote: > > Bear in mind that water or water/methanol injection will exert a powerful > cooling effect on the mixture rather than merely diluting the mixture > with hot, inert, gasses. > Bill in Boulder "Engineering as an Art Form" Hey, that's my idea. :-) Unfortunately you have to alter the air intake to compensate for the fuel displacement if water is injected, and methanol has a lower available btu, not to mention air/fuel ratio compared to gas. Burning dissimilar fuels in the same chamber seems to be a problem. Why not recover some exhaust or water-jacket heat by using it to drive a cooling unit, (like a propane fridge principle), to cool the air, and then jam as much air directly into the injector stream as possible. The rest of the air charge requirement is sucked up normally on the intake. (see other message on "For REALLY good injectors" for an echo of this, plus me dumping on another "INTRINSIC ENERGY IN MAGNET" guy. ------------------------------ From: djp@xxx.edu (Dick Protus) Date: Fri, 22 Aug 1997 14:29:24 -0400 (EDT) Subject: Re: injectors: dimensions and types; > > > >Brad Sheridan also asks about disc injectors; Brad, I would be interested > >in your findings on the subject of pintle/disc nozzle comparisons. > > I don't have too much yet, but I'll pass along what I do find. The reason > I'm asking is that The Triumph T595 motorcycle comes standard with the disc > type injectors. I've heard to avoid disc type injectors, but I want to know > more about why before I go switching them out. All I've heard so far is > that the disc type injectors aren't nearly as linear. I think Lucas is the > manufacturer of the disc injectors. > > Thanks, > Brad > > Disc type injectors are supposed to be less susceptable to clogging but also do not have as fine atomization as a pintle type. dick protus ------------------------------ From: "Steve Meade" Date: Fri, 22 Aug 1997 12:57:16 -0700 Subject: BOSCH stuff I have a bit of Bosch FI confusion. Porsche refers to the engine management system in my 944 as being Digital Motor Electronics. I thought that this pretty much translated into Motronic for all practical purposes. Then, I bought a Haynes manual for my car which says I have an L-Jetronic fuel injection system controlled by Digital Engine Electronics. To confuse matters even more, a Porsche site (non factory) proclaims me as having a JE-Jetronic system. This morning, I took apart part of the floor and got to the ECU to see exactly what it said. It is the familar "tab-cover" box with "Motronic" embossed in the case. I looked at the number on the box and it started with "261" the same as on my '87 BMW 325is with Motronic 1.1. Can any body shed some light on this subject? The car has an idle-air stabilizer valve just like my BMW and there are no signs anywhere of a separate idle controller so I think I may have Motronic 1.1. The connector on the box also looked like a double-row connector on the Motronic 1.1 boxes. Also, does anyone know the exact differences between JE-Jetronic, Jetronic, and Motronic? I know Motronic handles ignition as well but what about JE-jetronic? I've never seen that variant before. =-=-=-=-=-=-=-=-=-=-= Steve Meade smeade@xxx.com ------------------------------ From: senator@xxx.edu (Bill Bradley) Date: Fri, 22 Aug 1997 13:01:46 -0700 (PDT) Subject: Re: TPI Questions > > Bear in mind that water or water/methanol injection will exert a powerful > > cooling effect on the mixture rather than merely diluting the mixture > > with hot, inert, gasses. > > Bill in Boulder "Engineering as an Art Form" > > Hey, that's my idea. :-) Unfortunately you have to alter the air intake > to compensate for the fuel displacement if water is injected, and > methanol has a lower available btu, not to mention air/fuel ratio > compared to gas. Nope. The water or methanol replaces AIR, not fuel. The mixture goes rich running water or water-alcohol injection. Unless you're still running closed loop with the Oxygen sensor which will try to bring it back to stoic. > it to drive a cooling unit, (like a propane fridge principle), to cool > the air, and then jam as much air directly into the injector stream as > possible. The rest of the air charge requirement is sucked up normally > on the intake. I've considered the idea of a heat powered heat pump as a killer intercooler design. The drawbacks are that there are two common designs, one uses Hydrogen gas and Ammonia (not that namby-pamby 2.5% stuff that you use to clean things, REAL concentrated toxic, corrosive ammonia). The other system uses water and lithium bromide salt, much nicer, but has the annoying habit of freezing when it gets cold... Both systems also dump more heat OUT than you put in, so you have to have a decent cooling system for it as well. Bill ------------------------------ From: Terry Martin Date: Fri, 22 Aug 1997 16:50:32 -0700 Subject: Re: TPI Questions Bill Bradley wrote: > > > > Bear in mind that water or water/methanol injection ... > > > > you have to alter the air intake > > to compensate for the fuel displacement if water is injected... > > Nope. The water or methanol replaces AIR, not fuel... Um, okay. I was under the impression that oxygen, being 21% of the Air charge, was part of the fuel, and the other 79% being nitrogen, argon, & carbon dioxide were just hanging around because it's too much trouble to get rid of them. If you throw water in, 21% of the displaced Air is displaced fuel, hence it runs rich unless an adjustment is made to the Air charge, ie. turbo boost, or as you said, to the liquid fuel, losing volumetric efficiency. > > > it to drive a cooling unit, (like a propane fridge principle)... > > I've considered the idea of a heat powered heat pump as a killer > intercooler design... Both systems also dump more heat OUT > than you put in, so you have to have a decent cooling system for it as well. Exactly, and the excess heat coming out is coming from your intake charge before it's sucked into the cylinder. It just shifts the heat in the cycle out of the intake flow, to where it doesn't adversely affect volumetric efficiency. Getting rid of it is easy, just blow it into the air, since it's only hot air anyhow, and you've both recovered lost heat energy from the exhaust and improved the volumetric efficiency at the same time. Terry Terry ------------------------------ End of DIY_EFI Digest V2 #284 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".