looks like the stft, lambda, FP des, and FP rail go all funky once the ect hits 140. any ideas why?
looks like the stft, lambda, FP des, and FP rail go all funky once the ect hits 140. any ideas why?
2008 Sky RL
have you replaced your maf?
your vehicle might be entering closed loop at 140* at which point the maf gets leaned on very heavily... i would try to find a way to test the maf signals.
also did you change your optimal spark tables? your timing is like 8-10 at idle when everyone else runs smooth from 15-20
Last edited by cobaltssoverbooster; 10-01-2012 at 02:27 PM.
2000 Ford Mustang - Top Sportsman
nope stock maf.
does it not always run in closed loop? i thought closed loop is better since it adjusts according to what the engine is doing vs some preset tables.
is there a way to see in the scanner if its going from open to closed loop? i know my interceptor can show me but i cant have both running at the same time.
test the maf, like using a multimeter?
no i havent messed with the optimum spark tables. i dont understand how they work even after reading gmtechs thread on it. everything in the main spark advance and the optimum spark tables, around the idle rpm and load areas, is over well 20 so i dont know how i can raise where it actually runs at.
2008 Sky RL
nvm i logged it and its smooth and consistent. your maf is fine.
whats the current tune?
2000 Ford Mustang - Top Sportsman
im about to go pretty much back to the stock tune and redo everything to see if it still does it. ill post up the new log as soon as i can. thanks for the help btw.
2008 Sky RL
went back to stock and it does the same thing. weird.
2008 Sky RL
I would say you have 1 of three possible problems.
1) the 02 is bad or there's some form of leak in the exhaust that changes o2 readings.
2) the sensors to calculate air mass need individual testing. Ex: both maps, baro, iat,
Ect, ext.....
3) tb is acting up or there's an intake leak post maf.
Also there is a new recal for cobalt fuel pumps leaking including the lnf so may want to consider that too.
2000 Ford Mustang - Top Sportsman
1) i just swapped out the precat o2 less that 5k ago so i doubt its that. i used to have an exhaust leak where the cat meets the turbo but i fixed it already.
2) how do i test the sensors without buying new ones and swapping them out? i installed the gmpp 3bar sensors a while back, soldered not crimped.
3) wouldnt the log show if the tb was doing something funny? i can try and look for leaks post maf but i dont think there are any.
despite those three suggestions, why does it wait until the ect hits 140* and not as soon as i start it up?
2008 Sky RL
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