DIY_EFI Digest Friday, 17 May 1996 Volume 01 : Number 142 In this issue: Re: a/f ratio with LPG MAP sensor. ID this MAF Forwarded: Re: a/f ratio with LPG Re: a/f ratio with LPG Re: ID this MAF See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Paul E. Campbell" Date: Thu, 16 May 1996 10:13:07 -0400 (EDT) Subject: Re: a/f ratio with LPG > I was wondering if it is possible to use a normal (i.e petrol) O2 sensor > when running a car on LPG, as opposed to unleaded fuel. If it is a heated sensor (and most aren't), then yes. If not..you have to get it up to temperature before it works. Also as far as I know, those suckers don't actually measure oxygen. They measure ion concentrations of CO2 and they are also confused by NOx and CO. ------------------------------ From: "David W. Taylor" Date: Thu, 16 May 1996 12:57:49 -0700 Subject: MAP sensor. I'm newly subscribed so I apologise if this is old-hat , I am currently looking at options for optimising performance on a 94 Jeep wrangler with a Multi Port FI system and a MAP sensor. Does anyone have an FAQ on MAP operation or know of the best reference on MAP sensors specificly ?? I would like to convert my system to a flow based system to allow a turbo-charger or a small super charger. I believe the computer is a Chrysler re-badge of a GM unit, I plan on disecting one as soon as I find a spare. Thx for any info..... - -- David Taylor dwtaylor@xxx. My opinions are mine ,, and nobody elses. ------------------------------ From: Bob Valentine Date: Thu, 16 May 1996 19:14:40 -0400 (EDT) Subject: ID this MAF Anyone got a ID for this GM MAF: GM# 25007557 "BH" 3 wire connector Picked this up in a box of parts; just want to see what it is. Still looking for a GM TPI throttle body! --> Bob Valentine <-- --> ravalent@xxx.com <-- "Experience varies directly with equipment ruined" ------------------------------ From: RABBITT_Andrew@xxx.au Date: Fri, 17 May 1996 08:57:24 est Subject: Forwarded: Re: a/f ratio with LPG The heated EGO sensor is heated to enable closed loop A/F ratio control sooner after cold start-up since the Zirconium Dioxide element doesn't start working until about 300_C. The sensor does measure oxygen concentration. Once operational, the difference between heated and conventional sensors is not very much at all (heated sensors are supposed give a more stable output). (If it were confused with NOx and CO to any significant degree, then they would be absolutely useless in automotive applications where CO and NOx vary from nearly nothing to a whole heap) Andrew Rabbitt Orbital Engine Company From: ("Paul E. Campbell") pecampbe@xxx.edu:smtp Date: ## 05/16/96 10:13 ## > I was wondering if it is possible to use a normal (i.e petrol) O2 sensor > when running a car on LPG, as opposed to unleaded fuel. If it is a heated sensor (and most aren't), then yes. If not..you have to get it up to temperature before it works. Also as far as I know, those suckers don't actually measure oxygen. They measure ion concentrations of CO2 and they are also confused by NOx and CO. ------------------------------ From: Darrell Norquay Date: Thu, 16 May 96 21:21 PDT Subject: Re: a/f ratio with LPG At 01:31 PM 5/16/96 +1000, you wrote: >Hi everyone, > >I was wondering if it is possible to use a normal (i.e petrol) O2 sensor >when running a car on LPG, as opposed to unleaded fuel. > >Thanks in advance, > > Bruno. (u933234@xxx.au) > I've been running O2 sensors in my Camaro on LPG for a year or so now, but I'm still not sure they read back any useful info. The Stoich A/F ratio for propane is around 23:1, and although Stoich is Stoich no matter what the fuel (at least in theory), they seem to read lean most of the time. I'm reasonably certain that my mixture is not as lean as indicated, but I have the sensors mounted in the header collectors which is fairly far from the engine, so it may be a problem with location rather than the sensor itself. I want to try some heated sensors to see what difference it makes, I'll let you know what happens. By the way, O2 sensors do read oxygen content, at least in that they are proportional to the difference between the exhaust O2 concentration and the ambient air. They are unaffected by concentrations of other gases, and generate a voltage by pumping O2 across an electrochemical cell. Regards dn ------------------------------ From: Darrell Norquay Date: Thu, 16 May 96 21:21 PDT Subject: Re: ID this MAF At 07:14 PM 5/16/96 -0400, you wrote: > >Anyone got a ID for this GM MAF: > > GM# 25007557 "BH" > > 3 wire connector > >Picked this up in a box of parts; just want to see what it is. > >Still looking for a GM TPI throttle body! > > --> Bob Valentine <-- According to my Carter Engine Management controls book it was used in 1985-89 Camaros with MPFI in the 6 cyl 2.8L engines. That's the only reference I could find, although it may have been used in other models. As far as electrical connections, you'll have to check a Chiltons or Factory Service Manual. regards dn ------------------------------ End of DIY_EFI Digest V1 #142 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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