DIY_EFI Digest Friday, 12 September 1997 Volume 02 : Number 315 In this issue: Re: Propane on Fuel Injected Cars Re: Propane on Fuel Injected Cars RE: OBD II - fuel trims (adaptives) RE: Propane on Fuel Injected Cars Re: Propane on Fuel Injected Cars Re: OBD II - fuel trims (adaptives) O2 sensor output O2 sensor readings Re: O2 sensor output Re: Propane on Fuel Injected Cars See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Neall Booth Date: Thu, 11 Sep 1997 07:58:13 -0700 Subject: Re: Propane on Fuel Injected Cars Jim Davies wrote: > This package also used the 318 V8, and was available on pickups, vans and > RWD cop cars. Standard Impco parts were used, so I guess you could call it > TBI. BTW, they also had a 2.2 FWD propane car (never actually saw this > one, only the tech stuff. All this was Canada only, IIRC. Well, since IMPCO is technically a carburation system I would have to call it that. At this time the 318 V8 is Chrysler's only alternative fuels engine, as it has been for many years, and is expected to be up until 2003 (I think) when it will be phased out. The only good thing is that the alt fuels. package does offer hardened valve seats and guides, which is advantages for gaseous fuels like propane and CNG. I actually got a chance to see the 2.2 FWD vehicle. Again, it was an Impco type system, but it didn't last very long. Actaully, none of their carburated vehicles did. Neall - -- ********************************** Neall Booth Bi-Phase Technologies Development & Applications Engineer nbooth@xxx.net ********************************** ------------------------------ From: Jim Davies Date: Thu, 11 Sep 1997 06:56:10 -0700 (PDT) Subject: Re: Propane on Fuel Injected Cars On Thu, 11 Sep 1997, Neall Booth wrote: > Jim Davies wrote: > > > This package also used the 318 V8, and was available on pickups, vans and > > RWD cop cars. Standard Impco parts were used, so I guess you could call it > > TBI. > Well, since IMPCO is technically a carburation system I would have to > call it that. > It is? Where is the venturi? Jim Davies ------------------------------ From: James Boughton Date: Thu, 11 Sep 1997 10:05:31 -0400 Subject: RE: OBD II - fuel trims (adaptives) >If the vehicle was travelling at about 55 mph load and had a long term of >say -7%, and from the time it takes to accelerate to 65 mph and return to >closed loop, if in fact the computer ever left, the long term drops to >-11%, is this an acceptable amount of drift. (i.e. should the longterm >numbers move this rapidly or should it be a slow transition) Based on a >situation where the vehicle did not undergo a hot soak condition . You did not say if you acclerated to 65 at WOT or part throttle, but assuming part throttle it is possible that you changed the cell you were in and the long term adaptive in the 55mph cruise cell is -7% and the adaptive in the 65mph cruise cell is -11%. If you did not change cells and the long term actually changed I would say that is quite rapid, however, you are not saying that as you cruise the long term is updating all along which is what I would expect, especially with the short term adaptive hovering about +5%. The other thing that gets thrown into the mix is that it is going to depend on the guy who calibrated the package. He may have the long terms updating quickly, or very slowly, depending on what he likes to see happen. Calibrators are a strange breed and they all tend to have opinions on how things should be calibrated so you never know what might be causing what you are seeing. I would be interested in what tool you are using to obtain the data you see. It sounds pretty handy. Does it update quickly enough for you to see the oscillations of the short term adaptive? This should be in the 1-2 hz range, maybe a little slower at idle. >I realize that at WOT the computer is in open loop and on most of the >chryslers that I have seen there is no feedback what so ever, concerning >fuel trims (i.e. diagnostics tool outputs 0% for both.) Now the fact that >the F-150 did report fuel trims @xxx. You "hint" that these >are probably bogus numbers and I guess I will have to agree and take that >into account. However I have investigated what the fuel trims are in >closed loop just after letting off WOT. My long term is around -14%, which >brings me back to the question above which is how much drift is acceptable >and in what period of time. The still more confusing factor is that the >short term is +9%. It seems that as the pw increase the short and lon term >grow apart from each other. I swapped in new O2 sensors to see if that >would change anything, it brought them closer but significantly there was >no change. What the long term or short term adaptives do at WOT is strictly up to the software writer, and whether they are used at WOT is usually the result of some big meeting where the guy with the most political clout decides what he is going to tell everyone else to live with. Now, with OBDII I just remember something. If you do repeated WOTs and lifts you will drive a lot of hydrocarbons through the catalyst. If you begin updating your adaptives before the catalyst has had a chance to clean up again the down- stream O2 sensor will try to lean out the mixture. This may be causing some of the problem you are seeing. If you try an extended cruise I would expect the long terms to stabilize at some value and the short terms to oscillate around 0. More and more this is sounding like piss poor calibrating and the parts are all fine. Is there a particular drive problem that instigated this inquisition or are you just curious? Believe me cars from the factory aren't necessarily calibrated perfectly, my truck actually dies out if you go WOT rapidly while it is still warming up. Remember, the auto makers can sell cars that drive bad, but they can't sell cars that blow high emission numbers. Jim Boughton boughton@xxx.net ------------------------------ From: James Boughton Date: Thu, 11 Sep 1997 10:18:44 -0400 Subject: RE: Propane on Fuel Injected Cars Chrysler also had a 3.3L v-6 FFV package for several years. This was electronic port fuel injection for gasoline to 85% methanol. Jim Boughton boughton@xxx.net - ---------- From: Neall Booth[SMTP:nbooth@xxx.net] Sent: Thursday, September 11, 1997 10:58 AM To: diy_efi@xxx.edu Subject: Re: Propane on Fuel Injected Cars Jim Davies wrote: > This package also used the 318 V8, and was available on pickups, vans and > RWD cop cars. Standard Impco parts were used, so I guess you could call it > TBI. BTW, they also had a 2.2 FWD propane car (never actually saw this > one, only the tech stuff. All this was Canada only, IIRC. Well, since IMPCO is technically a carburation system I would have to call it that. At this time the 318 V8 is Chrysler's only alternative fuels engine, as it has been for many years, and is expected to be up until 2003 (I think) when it will be phased out. The only good thing is that the alt fuels. package does offer hardened valve seats and guides, which is advantages for gaseous fuels like propane and CNG. I actually got a chance to see the 2.2 FWD vehicle. Again, it was an Impco type system, but it didn't last very long. Actaully, none of their carburated vehicles did. Neall - -- ********************************** Neall Booth Bi-Phase Technologies Development & Applications Engineer nbooth@xxx.net ********************************** ------------------------------ From: Nass Jeff <"KOHLERNET/GENERATORS/NassJeff%Kohler Co."@xxx.COM> Date: Thu, 11 Sep 1997 10:49:55 -0400 (EDT) Subject: Re: Propane on Fuel Injected Cars The venturi signal lifts the gas valve. ---------- > > This package also used the 318 V8, and was available on pickups, vans and > > RWD cop cars. Standard Impco parts were used, so I guess you could call it > > TBI. > Well, since IMPCO is technically a carburation system I would have to > call it that. > It is? Where is the venturi? Jim Davies ------------------------------ From: "Niels Ezerman" Date: Thu, 11 Sep 1997 23:14:34 +0200 Subject: Re: OBD II - fuel trims (adaptives) Hello James, - ---------- > From: James Boughton > Subject: RE: OBD II - fuel trims (adaptives) > Date: 10. september 1997 17:46 > Oh, BTW, stoich at WOT is bad. Even though the EPA is trying > to mandate it nobody currently operates stoich at WOT. When > they do expect vehicle prices to rise. The engines should have > some great components in them, however. Thank you for the well explained text. I have just read about a new Audi V6 2.7l V5 BiTurbo, they have made an engine that operates Lambda 1 at WOT. The engine operates allways Lambda 1 up to between 3000-4000 Rpm and normally also at higher Rpm's too, if not one of the 6 exhaust temp. sensors are to high, then the Lambda goes down a little. Some data: 2.7l V6 90 deg. 400 Nm @ 1850-3600 / 195 kW 5800 Rpm 9.3:1 0.9 bar (13 psi) charge pressure Bosch Motronic ME7 By Niels Ezerman Silkeborg, DK nez@xxx.dk http://www.cybernet.dk/users/nez ------------------------------ From: "alex nicu" Date: Thu, 11 Sep 1997 18:01:25 PDT Subject: O2 sensor output Ok , I'll use the average between high and low , but , I have to set the perfect ( stoich ) point . The EFI unit will have to take a decision according with this point . It's one page on web where I read that this point for normal sensor it's arround 0.45V . OK , but yesterday on the list (#313) I read that the stoich point it's arround 0.6V . What's the real one ? Alex ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ From: John O Hornfeck Date: Thu, 11 Sep 1997 22:28:21 -0700 Subject: O2 sensor readings Ok, all you O2 experts: I nstalled my K&N A/F meter today on my MR2T and all seemed fine. The little lights up&down,up&down, then I go out on the highway and after 15 min of 70mph NO lights. "Oh damn, junk meter." BUT it starts working during the cool down (~4min). So I drive it some more in town and everythings fine. BUT when I take it out on the thru-way again the read out is gone, returning only after during prolonged idle. What the heck???? John O ------------------------------ From: Seth Date: Thu, 11 Sep 1997 20:21:36 -0700 (PDT) Subject: Re: O2 sensor output On Thu, 11 Sep 1997, alex nicu wrote: > Ok , I'll use the average between high and low , but , I have to set the > perfect ( stoich ) point . The EFI unit will have to take a decision > according with this point . > It's one page on web where I read that this point for normal sensor it's > arround 0.45V . OK , but yesterday on the list (#313) I read > that the stoich point it's arround 0.6V . What's the real one ? > Alex > > > ______________________________________________________ > Get Your Private, Free Email at http://www.hotmail.com > Alex- the curve is so steep at lambda=~1 that any value from 0.35to 0.75v might be considered stoich, depending on your definition. - -------------\ 0.9v | | | \ ------------- 0.1v ^ | the sacred lambda =1 appologies for the ascii art Seth Allen ------------------------------ From: Neall Booth Date: Thu, 11 Sep 1997 22:50:21 -0700 Subject: Re: Propane on Fuel Injected Cars Jim: > > Well, since IMPCO is technically a carburation system I would have to > > call it that. > > > It is? Where is the venturi? While I have never seen it, I have it from a good freind inside Chrysler Canada that it was an IMPCO type carbuartion system. There was a vapourizer and a carburator / mixer assembly, incorporating the gas valve for metering the fuel. Since I haven't seen it, I'm not sure how the underhood components were arranged. The system was produced in the early / mid eighties, long before any fuel injection systems for propane were ready for market. (fuel injection for both CNG and propane are both recent phenomina, 93+). Keep in mind, a propane carburator is not of the same type of design as a gasoline carburator. Neall - -- ********************************** Neall Booth Bi-Phase Technologies Development & Applications Engineer nbooth@xxx.net ********************************** ------------------------------ End of DIY_EFI Digest V2 #315 ***************************** 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".