Trying to finish my tune.
On a test drive the car runs ok when cold, (full acc and boost, no stuttering or popping.
Thr car has a new ecm, i have pinned out the ecm, check the harness and all senors that i have.
When hot it seems pops at wot back off just a bit and its good
As the car builds up to going wot the a/f is 12.0 and accels nicly,
push the pedal to wot and the popping starts. a/f is 13.5 and timing goes from 22-14.
i see that the maf khz is 127 when this happens. i went to that table and the top limit is 127.
i can only assume that i am reaching the top of my maf output table 6 as the numbers won't stay larger.
Is there a way to lift the limit of the tables?
Other things i have changed in the tune is shut off the egr as the car dosen't have this. set the timing tables to 0 for when it was on.
There are no cpu controlled fans so i set that high so it won't cause me any problems by tring to come on. i am receiving a quad drive fault a.
on this quad driver is the data dash (whitch i don't have)
low speed fan (no tin use,reason for turning off)
canister purge (car doen't have one)
and TCC brake switch (which i have to check to see if its connected.)
the last one here makes code 38 come on.
i have got the car to run better, seems not to have this problem when cold. which i am starting to belive is that the fuel is richer or the timing less or both.
Don't want to seem dopey but is there an attach file for this forum?
92 Pontiac 3.8 V6 S/C, MAF tuning
Moderators: Mangus, robertisaar, dex
My answer may not help much but I thought i would at least try!
13.5 a/f ratio at WOT? Have you tried running the vehicle richer? Maybe you need larger fuel injectors, or your current fuel injectors need to be cleaned. You could also try raising your fuel pressure a little just to test that idea out before you spend $$$ on some new injectors... Might want to make sure you have the proper octane rating for your fuel too.
Also you dont have any exhaust leaks do you? I had some and it through my O2 sensor way off. Might want to make sure your ignition system is in top shape too and it is able to fire correctly with the increased compression.
Hope something in there helps!
13.5 a/f ratio at WOT? Have you tried running the vehicle richer? Maybe you need larger fuel injectors, or your current fuel injectors need to be cleaned. You could also try raising your fuel pressure a little just to test that idea out before you spend $$$ on some new injectors... Might want to make sure you have the proper octane rating for your fuel too.
Also you dont have any exhaust leaks do you? I had some and it through my O2 sensor way off. Might want to make sure your ignition system is in top shape too and it is able to fire correctly with the increased compression.
Hope something in there helps!