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short fuel trim

G

gotboost3

New member
i dont understand what fuel trims are and how to diagnose them through my aeroforce when does it change and why where should it be at idle and wot? i need some insight on fuel trims so i know what i should be seeing because im throwing code P0133 and i read that its due to a slow response occuring with short fuel trim....lemmme know
 


Dont worry about STFT's .... LTFT's is what you need to watch... a + value means your running lean and the PCM is adding fuel. - Values mean your running rich and fuel is being removed.

Get ahold of a tuner and do some MAF tuning to correct these values. You want to be in the +3 or -3 range for LTFT's.
 
well at idle my ltft's are +16 an at wot im around -3 is that good or am i runninglean hence the headers and no tune?
 
You want your trims at WOT and PT to be at 0. The only way to get them there is with an AFC or a MAF tune. NOT a PCM.
 


gotboost3 said:
well at idle my ltft's are +16 an at wot im around -3 is that good or am i runninglean hence the headers and no tune?
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Well, it's pulling fuel for some reason at WOT which is not good. Also, the LTFT at +16 indicated a vac leak. Do you have your rear O2 removed by any chance?
 
wouldnt i be able to notice a vacuum leak on my boost gauge? my vacuum sits at 20 all day and driving its at 10 then at wot im at 6.5 psi....sounds right there are some ripped vacuum fitting on my tb and FPR tho maybe those are it....
 
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will you tune your car already. all those mods you threw at it have everything thrown off on your PCM.

besides, +16.4 at idle is usually a vacuum leak. 9 times out of 10.
 


Bio248 said:
will you tune your car already. all those mods you threw at it have everything thrown off on your PCM.

besides, +16.4 at idle is usually a vacuum leak. 9 times out of 10.
Click to expand...

thats exactly what i get at idle it stays at 16.4 never moves till i give it throttle or the cars moving...
 
damn i looked for a vacuum leak but i cant find one....got some loose fittings that i guesss could be leaking....could a bad canister purge solenoid cause this?
 
Hey buddy wounder if u can help me got a problem that comes n goes got tune pcm at idle im running good once im at cruise im all over the place like +20 to + 35 but when i step on it everything is working perfect as i look at the scanner - disconnected maf works good for a few minutes then everthing goes to hell readings all over the place.Need help
 


two places to look for a leak when you cant find one externally is the egr valve or the idle air control valve nine times out of ten its the idle air control
 
one thing you can try thats quick is to tap on the area around the idle air control valve with a hammer. if the idle inpromves then the valve isnt seating right but failure to notice a change doesnt mean the valve is good either
 
The code thats showing is p1133 and the fuel trim is maxing out at cruise O2 sensor was replaced 3 times maf sensor is ok checked it with it pluged and unpluged so basicly at idle its good at exceleration its good only at cruise everything goes to hell...
 
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