DIY_EFI Digest Sunday, 17 August 1997 Volume 02 : Number 278 In this issue: Re: TPI Questions Re: Fw: Eprom switcher Re: TPI Questions Re: TPI Questions Re: TPI Questions Admin test, don't bother See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: dzorde@xxx.com (dzorde) Date: Sat, 16 Aug 1997 09:46:03 -0700 (PDT) Subject: Re: TPI Questions I ended up finding a gas fitting that would fit a 5/8" pipe, and with a bit (well quite a lot) of teflon tape on the fitting it now screws into the return line of the tpi unit quite nicely. Don't ask about the size or thread of the fitting though, I have no idea what it is. Dan dzorde@xxx.com > > > > >I was planning on starting at 4 degrees advance, but increase after I get >the bugs worked out. Maybe I should reconsider. > >Sounds like you and I are doing the same thing... > >Do you know what type of fitting can be used for the return line (the >fitting on the TPI unit / fuel rail). >I can't seem to match that with anything. I have a fitting that fits the >line in, but not the return line. > >Also, has anyone used the MSD fuel pump? Summit sells these for about >$130.00. ------------------------------ From: clsnyde@xxx.net (Clare Snyder) Date: Sat, 16 Aug 1997 16:53:57 GMT Subject: Re: Fw: Eprom switcher I piggybacked two eproms, pin for pin, with the enable pins separated and switched - this was in a small computer, not an ecu > >---------- >> Von: Clare Snyder >> An: diy_efi@xxx.edu >> Betreff: Re: Eprom switcher >> Datum: Mittwoch, 13. August 1997 14:29 >> >> I missed the start of this thread. What are you trying to accomplish? I >have >> two eproms in the disk controller of my old COCO. They are connected in >> parallel, pin for pin, except for the enable pin, which has a simple spdt >> switch to select which prom is being accessed. This allowed use of two >> different operating systems, RSDOS and ADOS. I likely still have the >diagram >> in an old Rainbow magazine somewhere. >> > Hi, >The main problem is the space for an additional eprom in a small ECU. Some >have a seperate shielding box inside, so i would use the gatters, flipflop >and resistors as smd parts. It is easier to use a 27C512 eprom when only a >27C256 is normally needed and switch from the lower half to the upper half >(or do it with 4 sections when a 27C128 is standard) because of the same >ammount of pins. The additional parts are only necessary when i want to >switch under load; that is the real comfort. >Bye, >Peter >s68558@xxx.de > > ------------------------------ From: "George M. Dailey" Date: Sat, 16 Aug 1997 19:01:31 -0500 (CDT) Subject: Re: TPI Questions If it makes you feel any better, I could get only about 6 degrees max on 87 octane regular. -no EGR- GMD At 07:06 AM 8/14/97 -0700, you wrote: >Sorry I'm a bit late replying to this mail, but here goes. Yes it pings >without egr, mind you I have never tried it with egr so I can't compare. I >left egr off for the reason of getting max power, to combat the pinging I >have to run no more than 4deg advance and avgas. But I'm happy now. All I >need now are some rear tyres with grip. > >Dan dzorde$geocities.com > >> >> >> >> >>I was hoping someone would jump in here. >> >>Do you have any evidence of the engine knocking without EGR? >> >>I have the same question - do I want it or not? I'm also not concern with >>economy, only power. >> >> >> >> >> >>>I'm lost, for a performance engine, do you want egr or not ? When I built >>my tpi 350, I pulled the egr valve and stuck >a blanking plate over the >>hole instead, oh, I also put the little metal plates in the manifold >>gaskets where the egr is >meant to breathe through. Was this a mistake (I >>don't care about economy, only power)?>> >>> >>> >>>Dan dzorde@xxx.com >>> >>> >>>The EGR valve is still present and connected, but doesn't actually do >>>anything since there isn't a supply of exhaust gas to the valve. >>> >>>Grounding the EGR feedback wire will set off the SES light (it simulates >>>the EGR being stuck in the open position) >>> >>>Leaving it disconnected will also occasionally set off the SES light >>(there >are a few cases where the ECM will command the EGR to actuate, then >>look to >see what happened.) Fortunately, temps down here are high enough >>that this >doesn't happen often. (been about 4 months since the last time >>the code >went off) It will also clear itself within a few minutes of >>driving. >>> >>>Someday I'll have an EGR flange welded to one of the exhaust headers to >>>supply external EGR.. but it's a low priority. >> >> >> >> > > > George M. Dailey gmd@xxx.com ------------------------------ From: "George M. Dailey" Date: Sat, 16 Aug 1997 19:01:25 -0500 (CDT) Subject: Re: TPI Questions Hi Dan, what were you able to set the timing too without getting excessive detonation? I could only getabout 6 degrees with my egr plugged. GMD At 06:10 AM 8/12/97 -0700, you wrote: >I'm lost, for a performance engine, do you want egr or not ? When I built >my tpi 350, I pulled the egr valve and stuck a blanking plate over the hole >instead, oh, I also put the little metal plates in the manifold gaskets >where the egr is meant to breathe through. Was this a mistake (I don't care >about economy, only power)? > >Dan dzorde@xxx.com >>> Thanks for the help. >>> >>> This P/N thing is confusing. I have the JTR book (and a bunch others) >>and >>> most say not to ground this pin. >>> If I remember correctly something to do with idle and deceleration. >>Should >>> I be concerned???? >>> I think a lot of this is tied to an automatic transmission, not manual. >>Is >>> this true? >> >>I left mine open..sortta. I'm using Aluminum Corvette heads that do not >>have the internal EGR passages in combination with a '86 VIN "F" TPI >>manifold. >> >>The EGR valve is still present and connected, but doesn't actually do >>anything since there isn't a supply of exhaust gas to the valve. >> >>Grounding the EGR feedback wire will set off the SES light (it simulates >>the EGR being stuck in the open position) >> >>Leaving it disconnected will also occasionally set off the SES light (there >>are a few cases where the ECM will command the EGR to actuate, then look to >>see what happened.) Fortunately, temps down here are high enough that this >>doesn't happen often. (been about 4 months since the last time the code >>went off) It will also clear itself within a few minutes of driving. >> >>Someday I'll have an EGR flange welded to one of the exhaust headers to >>supply external EGR.. but it's a low priority. >> >>Curt Martin (cmartin@xxx.com) >>Ormond Beach, FL >>http://www.america.com/~cmartin >>'87 350 TPI Camaro.. (used to be a 2.8L V6 :) >> > > > George M. Dailey gmd@xxx.com ------------------------------ From: "George M. Dailey" Date: Sat, 16 Aug 1997 19:01:27 -0500 (CDT) Subject: Re: TPI Questions It appears that by not having the EGR system (with a stock ECM and engine), you will not be able to advance the timing to get the part throttle economy you deserve. Full throttle is unaffected by the EGR, but if you don't have the proper timing advance to begin with, you will not have it at WOT. The EGR system seems critical in setting the proper spark advance to begin with. Without it, you could run into detonation and as a result, have the timing retarded even futher. Has any one ever herd of an GM TPI EGR valve squeaking? My mom's car had this problem (Dodg K-car). Sounded like premature puppies yelping. I traced it to a resonance in the EGR valve. You could actually see it vibrating. My TPI engine (complete with defective EGR valve) makes a very simular sound. Dosen't seem like the EGR valve, especially since it's disconnected. GMD At 09:03 AM 8/12/97 -0500, you wrote: > > > > >I was hoping someone would jump in here. > >Do you have any evidence of the engine knocking without EGR? > >I have the same question - do I want it or not? I'm also not concern with >economy, only power. > > > > > >>I'm lost, for a performance engine, do you want egr or not ? When I built >my tpi 350, I pulled the egr valve and stuck >a blanking plate over the >hole instead, oh, I also put the little metal plates in the manifold >gaskets where the egr is >meant to breathe through. Was this a mistake (I >don't care about economy, only power)?>> >> >> >>Dan dzorde@xxx.com >> >> >>The EGR valve is still present and connected, but doesn't actually do >>anything since there isn't a supply of exhaust gas to the valve. >> >>Grounding the EGR feedback wire will set off the SES light (it simulates >>the EGR being stuck in the open position) >> >>Leaving it disconnected will also occasionally set off the SES light >(there >are a few cases where the ECM will command the EGR to actuate, then >look to >see what happened.) Fortunately, temps down here are high enough >that this >doesn't happen often. (been about 4 months since the last time >the code >went off) It will also clear itself within a few minutes of >driving. >> >>Someday I'll have an EGR flange welded to one of the exhaust headers to >>supply external EGR.. but it's a low priority. > > > > > George M. Dailey gmd@xxx.com ------------------------------ From: Johnny Date: Sat, 16 Aug 1997 19:25:35 -0700 Subject: Admin test, don't bother test 1 ------------------------------ End of DIY_EFI Digest V2 #278 ***************************** 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".