Will it work? I can get them for a pretty good price. If they compatible It will be a worth while mod.

does your chip change the A/F mixture? My problem is i have a 17.5:1 A/F mixture so i am VERY VERY rich. I assume your chip does change the mixture.. I am debating on if the AFC is going to be usefull on my TGP (if compatible) after your chip.

Shane

just a thought if its that rich your injectors maybe leaking at the pintle??  just think if you punch it and its leaking thats gonna make a super rich mixture.  Do you get blackish smoke out the tail when you punch it?  With the stock injectors I would get the black smoke with the accels I can put my foot to the floor and no smoke?!

Quote from: RedZMonteWill it work? I can get them for a pretty good price. If they compatible It will be a worth while mod.

does your chip change the A/F mixture? My problem is i have a 17.5:1 A/F mixture so i am VERY VERY rich. I assume your chip does change the mixture.. I am debating on if the AFC is going to be usefull on my TGP (if compatible) after your chip.

Shane

Sorry I did not catch this post, I can never keep up with all the emails and projects and posts too, I find the other board has less traffic and is easier to keep up with, but this one is better and more serious with many top-notch owners.

As for running the AFC, the ECM grounds 3 injectors from each bank of the motor, so if the AFC can handle that then sure, fire away.  The fueling there in the stock chip has enough overkill in boost fuel and an error in the fueling tables to make for a very rich/over-safe condition at all boost areas with 8 to 10 psi being the worst (depending on rpm at those points too!!).  McLaren and for that matter, any OEM will tune as rich as possible just this side of rich fuel bog/detonation (YES, you can detonate from being too rich too!!), this to make sure that the engine and its fuel pump/fuel filter/fuel injectors are safe at providing fuel for an engine when it gets 100K or 150K and more miles (within reason).  If everyone were to replace their fuel pump/filter/injectors every 80K miles, OEM and aftermarket chips could be tuned finer for max power, but there are other variable too numerous to list here that can also effect proper/safe fueling.  As you know there is also some inherent cooling from running extra fuel in the combustion chamber charge to make use of the latent heat of vaporization there (make sure you test and cofirm your final numbers on a hot day too!!). In my chip I do adjust that rich fueling, but still like to error some on the side of safety too while making more use of the engine/turbo/intercooler?s abilities, and rely on the active knock retard and even better boost retard should there be much detonation (and is why I HARP at anyone wanting to defeat ECM boost control!!!!).  After all my chip tuning was done, I proceeded to do extreme testing to my TGP engine to find out how weak, or if at all the engine components where.  Holding the boost manually to stop the ECM from backing it down when I knocked, and with 10 psi and stock timing added back in I hit 10 degree knock retard with no problems, 12 degrees and spark plug ground straps started to collapse, 14 degrees of knock retard and I totally lost a spark plug ground strap, 15 degree (max in chip but plenty with the boost retard also there) and past that I blew a head gasket, left my foot into it longer and fried a piston, but that was with 16 to 17 psi 92 octane and way more timing than was safe, I knew this would happen but since I was done tuning the chips I sell with safe power (and needed an excuse to rebuild/build-up my engine  :lol:  ), it was time to crank the boost and timing and see what flies, me or the engine parts (it was pretty fast for a while).  Rods held with no bends after taking everything apart, crank was fine, rod bearings showed a little hammering but not too bad, all in all its going to be pretty hard to hurt this engine, specially with a good chip and its knock and boost retard safety features!!! 8)

So, depending on the condition/age of your fuel pump, fuel filter and fuel injectors, you may find you can tune tighter just for your TGP, but like I said, there are other variables that play into this as well, combustion chamber build up is the most common and responsible for most differences, air and fuel quality with BOTH never being the same from day to day/tank to tank, and basically state of tune with all the sensors and such, and other variables.  Another I just remembered is the condition of the catalytic converter.  With the OEM pipe failing/cracking in as little as 3 to 6 months, since 1989-90 there have been a lot of TGPs running rich in closed loop (open loop is always rich) i.e. rich all the time that a lot of the cats out there are prone to be in some form of restriction or even plugged, so this has a strong impact on engine running as designed and the chip working with it, no chip has compensation for this condition/problem.  Hate to ask this and I KNOW you KNOW this but you stated you had an A/F ratio of 17.5:1, that was ?very very rich?? huh-huh, 17.5:1 is real lean, did you mean 10:1 or so?

Good luck and let us know how it goes.

Jeff M

the 17:1 is what was listed on the dyno print out.. tims said the same thing.. so i don't think it was accurate. But the fuel curve did indicate RICH RICH RICH and the dyno owner did also say it was SUPER RICH!

thanks,
Shane

Got that right, my wideband tests on stock chips was that number I quoted, 10:1 and 10.5:1 in a few areas, like you say, way on the side of rich.  Once you get to the 9:1 area or richer, things can start to knock under power, if you can explode that much fuel.  Now with a TGP that has a fuel pump and filter with 150K miles on them, no more 10:1  :)   I am sure your buddy's shop will get that WB adjusted for you and I would like to see that print out, I love input, more info no matter how much I have, it's nice to see more confirmation, and for the board, the same info from more people.  So will the S-AFC work with the injector/ECM wiring?

Good luck.
Jeff M