running too rich or too lean?

[deviousgst]

i recently got my motor rebuilt(forged Je pistons, eagle rods and cometic gaskets)(my mods are up to date) and since then its been cutting out wen i hit WOT. My set boost is at 20psi. Wen im like at 3krpms i hit wot and drags(hesitates) up to 10psi and anything after that it starts to cut out.
i havent got it tuned yet since i got it rebuilt can this be the problem. or is it jst running to rich or too lean...
thanks in advance

 

[rstare]

no i have not checked for boost leaks yet

Thats another possiblity, but its more likley your pump is pushing to much fuel because your not controlling it.

 

[ekstrom133]

Correct me if im wrong but the SAFC controls how much fuel is injected

 

[rEclipserGST]

It manipulates how much air is read thru the ECU. So by telling the ECU you have More or Less air, it adds More or Less fuel.

Your just Fooling the ECU, Tricks of the Trade.

BASICALLY it controls how long the injectors stay open and when they close (pulse wise)

 

[ekstrom133]

well i turned the boost down to 14 psi and found a boost leak at the coupler hose going to the intercooler so hopefully that was the problem

 

[tristanmb81]

i have my fingers crossed!

 

[deviousgst]

How much boost were you running before you rebuilt it.

Either way, you NEED a fuel pump, the stock one is simply not going to push enough fuel.
Pull your pump and see if its the OEM or a aftermarket one.

i was runnin 20psi of boost before the rebuild..im goin to check if i have the stock fuel pump or not...is it hard to change it

 

[delta448]

No, it's not hard to change it. You need a datalogger first and foremost. Once you know what is going on inside your engine then you will know the steps to take with your SAFC to correct your problems.

 

[joshs1074]

you should also do a fuel pump rewire when you change your fuel pump

 

[->PrOjEcTGS<-]

no boost leaks + no exhaust leaks + datalogger & WBO2 = Good Running Car.

 

[deviousgst]

Your stock fuel pump wont push enough fuel to your injectors once you start running about 16psi. You said you are running 20psi.
As I previously stated your not getting enough fuel with all that extra air your getting from the 20psi. You need a bigger pump, simple as that. If you turn down the boost I bet your car will run just fine. So either get a fuel pump (190lph, at minimum, or a 255, but then you need a afpr) or turn down the boost.

Edit: You cant tune what you dont have. You dont have enough fuel and you cant make the pump push more by tuning.

i was wondering how would i know if my MBC is disconnected because i think the stupid shop disconnected it and jst set my stock boost 20psi..because i lowered it on my MBC and it still goes up to 20psi..

 

[nyTalonTsi]

i just bought a tsi and its got a rewired 255 fuel pump and a afpr and its running real rich according to my wideband and the plugs are black but it had 750 injectors so i just swapped them with 560s and with the safc now it needs major tuning