DIY_EFI Digest Saturday, 6 March 1999 Volume 04 : Number 149 In this issue: Re: Voltage controller? Re: Wher to get ZIFs and EPROMs? DME EPROM Editor Software Re: aluminum intake cosmetics (Sand Blasting) Re: Which Intake Re: Miss in 87 Subaru RX Re: New to list, have a question. Re: New to list, have a question. Tuning SoftWare Injector Driver Re: Injector Driver AquaMist pump (was: Re: Voltage controller) Re: DME EPROM Editor Software RE: Injector Driver RE: Injector Driver Re: Injector Driver Re: AquaMist pump (was: Re: Voltage controller) Re: Injector Driver See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: rr Date: Sat, 06 Mar 1999 08:46:07 -0800 Subject: Re: Voltage controller? OK, finally got into this site (it can be reeeaaallll slow). This is an interesting pump. Basically, it is a solenoid driven pump. Figure a bicycle pump with a magnetic solenoid pulling back the rod, then a powerful spring returning the rod to the original position to pump. The pump stroke is run at about 50Hz. There are electronics built into the pump itself, no separate controller. According to the schematic, the input siganl is just an on/off as the water is required. They use a pressure switch. Bottom line, Dan, I don't think that you need anything else to drive this pump. It's all self-contained... BobR. Daniel Houlton wrote: > > rr wrote: > > > > I'm having some trouble following what you are saying. Can you post the > > URL for the Aqua-mist site? > > Sorry, I meant to include that but forgot. > > http://www.aquamist.co.uk/cp/sys1/sys1a.html#pump > > That's the paragraph where they say it's controlled by frequency. Follow > the "TECH-LINK" link at the end of the paragraph to get to the pump specs. > > > It sounds like the pump itself has some sort of controller built in, > > that needs another controller to run? > > That's the way it sounds. Reading the paragraph more closely, it does > state that it uses an on-board electronic controller. > > The "TECH" page says "pressure and delivery rate is regulated by internal > hi-tech electronic circuitry". Then the specs at the bottom say it takes > a 14V, 8A power source and a 0-12V, 5mA digital signal. Maybe it does > just take a 0-12V voltage signal and convert it to PWM internally? That's > kinda what it's starting to look like again. > > The word "digital" on the spec for the signal input is what made me think > is used a PWM signal. Maybe it's just a buzz-word or marketing thing to > make it sound fancier and it just uses a plain analog voltage signal? > > thanks > --Dan ------------------------------ From: rr Date: Sat, 06 Mar 1999 08:51:42 -0800 Subject: Re: Wher to get ZIFs and EPROMs? I've a bunch of EPROMS that I'll sell: NMC27C256Q-250 These are National Semiconductor 256's, CMOS, quartz windows, at 250ns access. They are pulls that I purchased from Astro Marketing. If these will do, $1 @xxx. I'm posting this so that maybe someone can help as to the access time, I don't know if these are correct for Ted's application. Nationals Web site has all the programming algo's for their EPROMS. BobR. Tedscj@xxx.com wrote: > > I just killed two memcals in one day pulling them out and putting them back in > and pulling them out .......etc. > Where do I get ZIF sockets and EPROMs so I can do this without ruining pins > and sockets? > Does anyone have any left over after buying in quantity? > Would anybody be interested in some if I have to buy a minimum order's worth? > > Thanks for any direction, > Ted ------------------------------ From: "Ezra Hall" Date: Sat, 6 Mar 1999 09:39:50 -0500 Subject: DME EPROM Editor Software Folks, Check out the following URL: http://www.bonnevillemotorwerks.com/dmeedit.html I downloaded the demo software, and was able to view EPROM data from my Motronic unit. The demo software doesn't allow saving of data. I have sent a request for pricing info. Enjoy! Ezra Hall ------------------------------ From: "Gary Derian" Date: Sat, 6 Mar 1999 11:50:53 -0500 Subject: Re: aluminum intake cosmetics (Sand Blasting) I plumb an old car A/C condenser in the air line. For painting cars, I put a bag of ice on it. It condenses all the liquid water out of the air. The two separators I have fill up quickly. Gary Derian >Let me second Jim's comment. Keep the sand Dry! I had a lot >of problems with my pressurized sandblaster clogging. It was >caused by moisture in the compressed air. I had a water trap >on the input to the sandblaster, but it didn't work in the >humid northeast summers. I moved the compressor to my >basement, and put 30 feet of copper tubing looped through my >Basement (usually 10 degrees cooler than the outside temp). >My water seperator really started to fill up, and my >sandblaster stopped clogging. Cooling the air really helped >seperate the water, and gave me dryer air. > > Ken > ------------------------------ From: WLundquist@xxx.com Date: Sat, 6 Mar 1999 12:32:43 EST Subject: Re: Which Intake Dave, If you have a copy of Jeff Hartmans' FUEL INJECTION book, look on page 90, and note that the top left photo if a small block chevy that is twin turboed and uses a moon manifold. This is an exellent manifold to start with. My only concern is where the throttle blades are located. The turbo will quickly lose rpm with the blades after the turbo. To counter act that condition a relief valve needs to be installed in the pipe between the turbo and the tb's to maintain rpm. A better alternative is to put the tb's before the turbo inlet so that when the tb's are closed the turbo will spin in a vacuum and maintain rpm, this will make for guicker recovery when you stab the throttle. See Hugh McInnes TURBOCHARGERS book. It is very complete. Gail Banks is another exellent source. The cost of any custom installation you do won't be cheap. But if you have put the $$$ in the engine don't short change the intake. Read The Performance Professor's lectures (Racepages.com) on air flow, intake systems and the like. If you would like more info or assistance in building components, I have done some fabrication on turbo systems. If you want references, contact Archer Motorsports. TIA Wayne ------------------------------ From: Tony Garcia Date: Tue, 23 Feb 1999 08:13:21 -0500 Subject: Re: Miss in 87 Subaru RX Benjamin Marsh wrote: > > I have an 1987 subaru RX with the mpfi turbo engine. > The problem occurs when the engine is at normal operating > temperature but not always - driving along at moderate > loads and higher the car sometimes misses, backing off > doesn't fix the problem and the car eventually rolls to > a stop. If I wait until the car cools down sufficiently > it goes again just fine - until it heats up. There is also > a fair amount of fuel smoke associated with the car stopping > which leads me to believe it is an ignition problem. > > Over the past 6 months this has happened three times. > 1st I replaced the O2 sensor - problem went away. > 2nd I replaced the O2 sensor - problem went away, until > that evening when it happened again - I replaced spark plugs > and again problem went away, that was about 6 weeks ago > now it has happened again... > > I have a computer fault code of 33 which corresponds to > a speed sensor malfunction, no other fault codes show up > the SS fault shows up all the time, when the car misses though > the ECS light flashes on and off - the speed sensor is still the > only fault code shown. Last time it happened I had a boost gauge > in the car which showed that during the miss I was getting full > boost at full throttle even though the tach was showing at below > 1000rpm this indicates I am still getting fuel into the engine > which is going through into the exhaust and spooling the turbo. > > Does anybody have any idea what could possibly be causing this? > > BTW my local Subaru dealer has no idea - he says he has less > of an idea than I do due to not having seen one of these cars > before I brought it to him... > > Thank you for your help > > Ben Marsh Hey Ben My name is Tony and I work for a Subaru Dealer. 1st thing is check the ground wire on the right side of the intake it uses one of the bolts to secure it to the block it should be tite and no corrosion.That ground controls the igntion and injector. 2nd with the car running put water in a squirt bottle and spray the wires,coil,everything and see if the car acts up. 3rd check the ground wire at the starter could be loose. I don`t beleive that the speed sensor has anthing to do with it.Have you tryed to drive the car with the d-check conectors connected to catch the lite flashing.Hope this info can helpn you . Tony P.S. if you have any questions drop me a line ------------------------------ From: esc Date: Sat, 06 Mar 1999 13:43:06 -0600 Subject: Re: New to list, have a question. >Eric, I also have an early ProJection .... doesn't have the EGO >feedback though. This is probably not going to be any real help >to you, but I thought I'd share some quick thoughts with you > > . the projection is an alpha-n controller -- only uses rpm and >tps to determine fuel flow > > . the temp input is, as best as I can determine, basically an >on-off kind of thing to enrich the mixture and energize the throttle >kicker, so I don't consider it a bona fide "input" for normal >operation Correct, it does nothing once the engine reaches normal temp. > > . the "ego feedback" unit is only to keep the system closer to >stoic ...... a problem I constantly have is the unit always runs >rich .... it can be adjusted leaner, but then it will run entirely >too lean at certain points (I have a DPM watching an EGO, so I >get a little "feedback" myself ;-) I have an old K&N O2 guage that I used before I got the closed loop kit. I still use it for base line tuning, it is very helpfull. >... if you agree with the above (that the ego feeback is to try to >keep the unit from running so rich, and maybe to prevent the operating >points where it also runs too lean, and that it's not to really improve >on the operating characteristics of the unit ....) It does help my mileage a lot, at the expence of throttle responce. Thats why I installed an easily accessed disable switch for it. The main problem I have with the Closed loop kit has to do with how it modifies the TPS voltage. Generally the baseline mixture is too rich so it leans it out. If it(closed loop kit) leans the mixture very much then when you give a little more throttle it gets very lean and does not accelerate properly. This kit does not function above 2/3 throttle, so I find myself often applying a lot more throttle than would otherwise be needed just to avoid the closed-loop-kit-induced flat spot. > . then, consider that a MAP input might be more logical ?? I had >entertained the idea of either building my own ego feedback unit or >a map feedback unit -- or could actually sum the two together ?? All >that's needed is to sum the input from the tps with the conditioned >voltage(s) from the other devices. To me, the map input makes more >sense and would elevate the unit from the status of simple alpha-n >controller to a simple speed-density unit (which their literature >claims it is anyway!). > >Tom Cloud I agree that a MAP input is what I need. Without it the Ram-air system will always be troublesome. The problem is how do I do it? I really like the throttle body part of the ProJection, but thats the only part I really want to keep. I'm not all that happy with the controller. I really want something that I can have more control over and that will accept input from more sources. Eric esc@xxx.com If it breaks, make it stronger. If it doesn't, try harder. '68 Big Block Bird '69 Spitfire '82(sort of) Camaro ------------------------------ From: "Bruce Plecan" Date: Sat, 6 Mar 1999 17:24:30 -0500 Subject: Re: New to list, have a question. - -----Original Message----- From: esc To: diy_efi@xxx.edu> Date: Saturday, March 06, 1999 2:42 PM Subject: Re: New to list, have a question. For the effort your talking about, why not just use an eom ecm. Junkyard available, and with some misc bits, maybe $150ish, be able to reprogram it, and do a say 747.. If ya went 747 just reading programming 101 would be lots of help Bruce >>Eric, I also have an early ProJection .... doesn't have the EGO >>feedback though. This is probably not going to be any real help >>to you, but I thought I'd share some quick thoughts with you >> >> . the projection is an alpha-n controller -- only uses rpm and >>tps to determine fuel flow >> >> . the temp input is, as best as I can determine, basically an >>on-off kind of thing to enrich the mixture and energize the throttle >>kicker, so I don't consider it a bona fide "input" for normal >>operation > >Correct, it does nothing once the engine reaches normal temp. > >> >> . the "ego feedback" unit is only to keep the system closer to >>stoic ...... a problem I constantly have is the unit always runs >>rich .... it can be adjusted leaner, but then it will run entirely >>too lean at certain points (I have a DPM watching an EGO, so I >>get a little "feedback" myself ;-) > >I have an old K&N O2 guage that I used before I got the closed loop kit. >I still use it for base line tuning, it is very helpfull. > > >>... if you agree with the above (that the ego feeback is to try to >>keep the unit from running so rich, and maybe to prevent the operating >>points where it also runs too lean, and that it's not to really improve >>on the operating characteristics of the unit ....) > >It does help my mileage a lot, at the expence of throttle responce. Thats >why I installed an easily accessed disable switch for it. > >The main problem I have with the Closed loop kit has to do with how it >modifies the TPS voltage. Generally the baseline mixture is too rich so it >leans it out. If it(closed loop kit) leans the mixture very much then >when you give a little more throttle it gets very lean and does not >accelerate properly. This kit does not function above 2/3 throttle, so I >find myself often applying a lot more throttle than would otherwise be >needed just to avoid the closed-loop-kit-induced flat spot. > > >> . then, consider that a MAP input might be more logical ?? I had >>entertained the idea of either building my own ego feedback unit or >>a map feedback unit -- or could actually sum the two together ?? All >>that's needed is to sum the input from the tps with the conditioned >>voltage(s) from the other devices. To me, the map input makes more >>sense and would elevate the unit from the status of simple alpha-n >>controller to a simple speed-density unit (which their literature >>claims it is anyway!). >> >>Tom Cloud > > >I agree that a MAP input is what I need. Without it the Ram-air system >will always be troublesome. >The problem is how do I do it? > >I really like the throttle body part of the ProJection, but thats the only >part I really want to keep. I'm not all that happy with the controller. I >really want something that I can have more control over and that will >accept input from more sources. > >Eric >esc@xxx.com >If it breaks, make it stronger. >If it doesn't, try harder. >'68 Big Block Bird >'69 Spitfire >'82(sort of) Camaro > ------------------------------ From: m.cortecchia@xxx.it (Marco Cortecchia) Date: Sat, 06 Mar 1999 23:27:31 +0100 Subject: Tuning SoftWare Hi, My name is Marco Cortecchia , I'm a Mechanincal Engineering student in Bologna's University . My work is SoftWare developing for Mechanical engineerieng and ECU&CHIP tuning . I just write the release 2.0 of my SoftWare Eprom Wizard . It's a general pourpose SoftWare for ECU tuning and it can manage the new 16 bit Racelogic EPROM Emulator ( with realtime changes and Trace ) . If You are interest , You can visit my Web site : www.3wad.com/efi/ I'm ready to reply to Your questions . Best Regards MARCO CORTECCHIA ( SoftWare developer ) Via Bellini 70/A 40026 - Imola ( BO ) ITALIA Tel/Fax : +39-(0)542-681936 m.cortecchia@xxx.it www.3wad.com/efi ------------------------------ From: "Walter Sherwin" Date: Sat, 6 Mar 1999 17:28:37 -0800 Subject: Injector Driver This is a multi-part message in MIME format. - ------=_NextPart_000_0022_01BE67F6.C4DBAFA0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Has anyone played with the injector driver circuitry (two channel TBI - = peak&hold) as found in the 16147060 PCM? This box is from a 91-93 = light duty truck with 4L80E. I want to force the drivers to operate as = either 6/1.5 A or 8/2 A units, instead of as conventional 4/1 A units. =20 I know that this is physically possible, by tailoring the two "current = sense" resistors in the circuit, but I am wondering if anyone knows = whether the rest of the components will stand up to this current abuse? = Thanks; Walt. =20 - ------=_NextPart_000_0022_01BE67F6.C4DBAFA0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Has anyone played with the injector driver circuitry = (two=20 channel TBI - peak&hold) as found in the 16147060 PCM?   = This box=20 is from a 91-93 light duty truck with 4L80E.  I want to force the = drivers=20 to operate as either 6/1.5 A or 8/2 A units, instead of as conventional = 4/1 A=20 units. 
 
I know that this is physically possible, by = tailoring the two=20 "current sense" resistors in the circuit, but I am wondering = if anyone=20 knows whether the rest of the components will stand up to this  = current=20 abuse? 
 
Thanks;
Walt.
 
 
 
- ------=_NextPart_000_0022_01BE67F6.C4DBAFA0-- ------------------------------ From: "Clarence L.Snyder" Date: Sat, 06 Mar 1999 17:53:48 -0500 Subject: Re: Injector Driver If my injectors are 14 ohm units, I should be able to drive them with a simple saturated switch driver without any problem, should I not? I was looking at the Cherries and National chips, but just a simple MosFet should work ok in this case? 1 amp per injector at 14 volts. Is there any advantage to complicating the system with more smarts than are necessary? This is a simple, bare bones, dumb-as-a-post analog injection system with manual trim - so far only 4 components plus injector. This does not include the trigger circuitry, which I hope tomake just as simple. ------------------------------ From: Daniel Houlton Date: Sat, 6 Mar 1999 16:17:23 -0700 (MST) Subject: AquaMist pump (was: Re: Voltage controller) rr wrote: > > OK, finally got into this site (it can be reeeaaallll slow). This is > an interesting pump. Basically, it is a solenoid driven pump. Figure > a bicycle pump with a magnetic solenoid pulling back the rod, then a > powerful spring returning the rod to the original position to pump. > The pump stroke is run at about 50Hz. > > There are electronics built into the pump itself, no separate > controller. > According to the schematic, the input siganl is just an on/off as the > water is required. They use a pressure switch. > > Bottom line, Dan, I don't think that you need anything else to drive > this pump. It's all self-contained... Yeah it looks that way, but it can still be controlled to vary the amount of injection by controlling the pressure. The basic system comes with an on/of pressure switch which means you get all or none. Their upper-level kit includes their fuel injector control box which also has an output for this pump. It increases pump pressure and therefor the amount of water injected as the boost pressure goes up. That's basically what I want to do. Provide a variable voltage signal (looks like 0 - 12V) to increase water pressure as boost goes up. If I could get this signal from the 0 - 5V a MAP sensor gives, I can get a nice water injection curve instead of turning it on full blast at X psi with a pressure switch. Use the pressure switch that comes with the pump to arm the system and prevent injection before 3 psi say. Then map the MAP output so that the pump gets about 6V (half pressure) at say 3 psi and then ramps up rapidly to deliver 12V (full pressure) by 8 or 9 psi. Someone mentioned an op-amp could do this. Also a 555. What is a 555? Is that a particular op-amp? I remember it being referred to as a timer someone used to drive and additional injector from the signal to a stock one. For now I'll start studying op-amps. Thanks for the help. - --Dan ------------------------------ From: "Ezra Hall" Date: Sat, 6 Mar 1999 18:38:59 -0500 Subject: Re: DME EPROM Editor Software oops, in my rush to try the software this am before leaving for the day, I didn't verify that when I loaded my EPROM data that it actually was loading my EPROM data. In fact, it only loaded the demo bin they include with the trial version of the software. The Help files specify that configuration files have to be purchased for each DME unit and EPROM combination (in addition to the actual software cost of course). Sorry for any confusion... >I downloaded the demo software, and was able to view EPROM data from my >Motronic unit. The demo software doesn't allow saving of data. I have sent a >request for pricing info. ------------------------------ From: "Ward Spoonemore" Date: Sat, 6 Mar 1999 16:02:43 -0800 Subject: RE: Injector Driver This is a multi-part message in MIME format. - ------=_NextPart_000_0015_01BE67EA.C4A86110 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit If you want more than 2 drivers your out of luck, there are only two drives on the board, If you want 6 or 8 standard PFI injectors, GM uses 3 or 4 (6/8) in two batches. for PFI, the 94/95 PCM has a software mode switch for CPI/PFI and TBI. This is not to change the drivers but to change calibration functions. This is a much bigger thing than wiring up some injectors. This answer your question ? Ward -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of Walter Sherwin Sent: Saturday, March 06, 1999 5:29 PM To: gmecm@xxx.edu; DIY_EFI Subject: Injector Driver Has anyone played with the injector driver circuitry (two channel TBI - peak&hold) as found in the 16147060 PCM? This box is from a 91-93 light duty truck with 4L80E. I want to force the drivers to operate as either 6/1.5 A or 8/2 A units, instead of as conventional 4/1 A units. I know that this is physically possible, by tailoring the two "current sense" resistors in the circuit, but I am wondering if anyone knows whether the rest of the components will stand up to this current abuse? Thanks; Walt. - ------=_NextPart_000_0015_01BE67EA.C4A86110 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
If you=20 want more than 2 drivers your out of luck, there are only two drives on = the=20 board,
If you want 6 or 8 standard PFI injectors, GM uses = 3 or 4=20 (6/8) in two batches. for PFI, the 94/95 PCM has a software mode switch = for=20 CPI/PFI and TBI. This is not to change the drivers but to change = calibration=20 functions. This is a much bigger thing than wiring up some = injectors.  This=20 answer your question ?
Ward
-----Original Message-----
From:=20 owner-diy_efi@xxx.edu=20 [mailto:owner-diy_efi@xxx.edu]On Behalf Of = Walter=20 Sherwin
Sent: Saturday, March 06, 1999 5:29 = PM
To:=20 gmecm@xxx.edu; DIY_EFI
Subject: Injector = Driver

Has anyone played with the injector driver = circuitry (two=20 channel TBI - peak&hold) as found in the 16147060 = PCM?   This=20 box is from a 91-93 light duty truck with 4L80E.  I want to = force the=20 drivers to operate as either 6/1.5 A or 8/2 A units, instead of as=20 conventional 4/1 A units. 
 
I know that this is physically possible, by = tailoring the=20 two "current sense" resistors in the circuit, but I am = wondering=20 if anyone knows whether the rest of the components will stand up to=20 this  current abuse? 
 
Thanks;
Walt.
 
 
 
- ------=_NextPart_000_0015_01BE67EA.C4A86110-- ------------------------------ From: "Ward Spoonemore" Date: Sat, 6 Mar 1999 16:05:13 -0800 Subject: RE: Injector Driver A TI TIP102 is a simple driver, a NPN darlington xistor probably aviable from radio shack, works good, lasts long time Ward - -----Original Message----- From: owner-diy_efi@xxx.edu [mailto:owner-diy_efi@xxx.edu]On Behalf Of Clarence L.Snyder Sent: Saturday, March 06, 1999 2:54 PM To: diy_efi@xxx.edu Subject: Re: Injector Driver If my injectors are 14 ohm units, I should be able to drive them with a simple saturated switch driver without any problem, should I not? I was looking at the Cherries and National chips, but just a simple MosFet should work ok in this case? 1 amp per injector at 14 volts. Is there any advantage to complicating the system with more smarts than are necessary? This is a simple, bare bones, dumb-as-a-post analog injection system with manual trim - so far only 4 components plus injector. This does not include the trigger circuitry, which I hope tomake just as simple. ------------------------------ From: "Walter Sherwin" Date: Sat, 6 Mar 1999 20:48:32 -0800 Subject: Re: Injector Driver This is a multi-part message in MIME format. - ------=_NextPart_000_0031_01BE6812.B2588BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Not really what I had in mind Ward, but thanks anyways! I want to use = this PCM to drive 4 Rochester TBI injectors instead of two, in delayed = channel synchronous TBI mode (picture a PCM driving a 900 CFM Holley). = But, I would much prefer to drive the injectors as two series "pairs", = directly via the PCM, as opposed to through the custom external 2-4 = channel P&H driver box that I have at the current time. If everything is perfect on my bench tester, I can in fact drive the two = pairs of injectors with the GM 4/1 A drivers. However, the injectors = are somewhat more sluggish, and in a real vehicle I would suspect that I = could/would have problems with things such as low battery voltage, = cranking conditions, and thermal soak. For this reason, I am looking to = "boost" the injector current a little bit, effectively turning the 4/1 A = drivers into say a 6/1.5 A drivers, or even something a fuzz higher. After cannibalizing an old PCM, I think I have identified the = appropriate peak to hold current "sense" resistors (.1 ohm), and the = driver elements. I cannot find a cross reference for the driver, but I = do see an "8A" stamped on its face, so I assume that it is rated for 8 = amps?? Probably peak?? I'm going to hook this thing up and let it rip for a few days, to see = what happens. I just thought I'd first see if anyone else had fiddled = with such an idea, and what their experience had been. =20 Thanks; Walt. -----Original Message----- From: Ward Spoonemore To: diy_efi@xxx.edu = Date: Saturday, March 06, 1999 4:32 PM Subject: RE: Injector Driver =20 =20 If you want more than 2 drivers your out of luck, there are only two = drives on the board,=20 If you want 6 or 8 standard PFI injectors, GM uses 3 or 4 (6/8) in = two batches. for PFI, the 94/95 PCM has a software mode switch for = CPI/PFI and TBI. This is not to change the drivers but to change = calibration functions. This is a much bigger thing than wiring up some = injectors. This answer your question ? Ward -----Original Message----- From: owner-diy_efi@xxx.edu = [mailto:owner-diy_efi@xxx.edu]On Behalf Of Walter = Sherwin Sent: Saturday, March 06, 1999 5:29 PM To: gmecm@xxx.edu; DIY_EFI Subject: Injector Driver =20 =20 Has anyone played with the injector driver circuitry (two = channel TBI - peak&hold) as found in the 16147060 PCM? This box is = from a 91-93 light duty truck with 4L80E. I want to force the drivers = to operate as either 6/1.5 A or 8/2 A units, instead of as conventional = 4/1 A units. =20 =20 I know that this is physically possible, by tailoring the two = "current sense" resistors in the circuit, but I am wondering if anyone = knows whether the rest of the components will stand up to this current = abuse?=20 =20 Thanks; Walt. =20 =20 =20 - ------=_NextPart_000_0031_01BE6812.B2588BC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Not really what I had in mind Ward, = but thanks=20 anyways!  I want to use this PCM to drive 4 Rochester TBI injectors = instead=20 of two, in delayed channel synchronous TBI mode (picture a PCM driving a = 900 CFM=20 Holley).   But, I would much prefer to drive the injectors as = two=20 series "pairs", directly via the PCM, as opposed to through = the custom=20 external 2-4 channel P&H driver box that I have at the current=20 time.
 
If everything is perfect on my bench tester, I can = in fact=20 drive the two pairs of injectors with the GM 4/1 A drivers.  = However, the=20 injectors are somewhat more sluggish, and in a real vehicle I would = suspect that=20 I could/would have problems with things such as low battery voltage, = cranking=20 conditions, and thermal soak. For this reason, I am looking to = "boost"=20 the injector current a little bit, effectively turning the 4/1 A drivers = into=20 say a 6/1.5 A drivers, or even something a fuzz higher.
 
After cannibalizing an old PCM, I think I have = identified the=20 appropriate peak  to hold current "sense" resistors (.1 = ohm), and=20 the driver elements.  I cannot find a cross reference for the = driver, but I=20 do see an "8A" stamped on its face, so I assume that it is = rated for 8=20 amps??  Probably peak??
 
I'm going to hook this thing up and let it rip for a = few days,=20 to see what happens.  I just thought I'd first see if anyone else = had=20 fiddled with such an idea, and what their experience had been. =20
 
 
Thanks;
Walt.
 
 
 
-----Original = Message-----
From:=20 Ward Spoonemore <>
T= o:=20 =20 <>
Date:=20 Saturday, March 06, 1999 4:32 PM
Subject: RE: Injector = Driver

If=20 you want more than 2 drivers your out of luck, there are only two = drives on=20 the board,
If you want 6 or 8 standard PFI injectors, GM = uses 3 or 4=20 (6/8) in two batches. for PFI, the 94/95 PCM has a software mode = switch for=20 CPI/PFI and TBI. This is not to change the drivers but to change = calibration=20 functions. This is a much bigger thing than wiring up some = injectors. =20 This answer your question ?
Ward
-----Original Message-----
From:=20 owner-diy_efi@xxx.edu=20 [mailto:owner-diy_efi@xxx.edu]On Behalf = Of=20 Walter Sherwin
Sent: Saturday, March 06, 1999 5:29=20 PM
To: gmecm@xxx.edu;=20 DIY_EFI
Subject: Injector Driver

Has anyone played with the injector driver = circuitry=20 (two channel TBI - peak&hold) as found in the 16147060=20 PCM?   This box is from a 91-93 light duty truck with=20 4L80E.  I want to force the drivers to operate as either = 6/1.5 A or=20 8/2 A units, instead of as conventional 4/1 A units.  =
 
I know that this is physically possible, by = tailoring=20 the two "current sense" resistors in the circuit, but = I am=20 wondering if anyone knows whether the rest of the components = will stand=20 up to this  current abuse? 
 
Thanks;
Walt.
 
 
 
- ------=_NextPart_000_0031_01BE6812.B2588BC0-- ------------------------------ From: "Ord Millar" Date: Sat, 6 Mar 1999 21:40:09 -0400 Subject: Re: AquaMist pump (was: Re: Voltage controller) 555 is a timer. Pretty handy, with two resistors & a capacitor you can make a pulsing output, and the frequency is pretty stable when supply voltage changes. It can also be used for a one-shot pulse, amoung other things. Also comes in a dual version, 556. You can find them in TI data books, also Signetics, usually listed under "Special Function". No one should be without a few! > >Someone mentioned an op-amp could do this. Also a 555. What is a >555? Is that a particular op-amp? I remember it being referred to as >a timer someone used to drive and additional injector from the signal >to a stock one. > >For now I'll start studying op-amps. Thanks for the help. > >--Dan > ------------------------------ From: "Bruce Plecan" Date: Sat, 6 Mar 1999 22:45:42 -0500 Subject: Re: Injector Driver This is a multi-part message in MIME format. - ------=_NextPart_000_0043_01BE6823.1088D6E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 =20 Not really what I had in mind Ward, but thanks anyways! I want to = use this PCM to drive 4 Rochester TBI injectors instead of two, in = delayed channel synchronous TBI mode (picture a PCM driving a 900 CFM = Holley). But, I would much prefer to drive the injectors as two series = "pairs", directly via the PCM, as opposed to through the custom external = 2-4 channel P&H driver box that I have at the current time. =20 That is what Howell does with their 730/Holley TBI Conversion. I've wired up 16 TPI injectors into 2 groups of 8, and while a = "normal group" runs down to less than 1 msec. when paired 2 is erratic. Will be dooing more = testing on this as equipment appears. On the 749 ecm there is in fact a wiring difference that = allowseither P+H, or Saturated mode. The saturated uses just one driver, and the P+H two. HTH Bruce - ------=_NextPart_000_0043_01BE6823.1088D6E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

 
Not really what I had in mind = Ward, but=20 thanks anyways!  I want to use this PCM to drive 4 Rochester = TBI=20 injectors instead of two, in delayed channel synchronous TBI mode = (picture a=20 PCM driving a 900 CFM Holley).   But, I would much prefer = to drive=20 the injectors as two series "pairs", directly via the PCM, = as=20 opposed to through the custom external 2-4 channel P&H driver = box that I=20 have at the current time.
 
That is what Howell does with their 730/Holley = TBI=20 Conversion.
I've wired up 16 TPI injectors into 2 groups of = 8, and=20 while a "normal group" runs down
to less than 1 msec. when paired 2 is = erratic.  Will=20 be dooing more testing on this as
equipment appears.
   On the 749 ecm there is in fact a = wiring=20 difference that allowseither P+H, or Saturated
mode.  The saturated uses just one driver, = and the=20 P+H two.
HTH
Bruce
=
 
- ------=_NextPart_000_0043_01BE6823.1088D6E0-- ------------------------------ End of DIY_EFI Digest V4 #149 ***************************** 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".