Extremely lean when accelerating!??

[/\G]

OK I had this problem for somtime now, My car runs fine, it doesnt stall, but it is not as fast as it should be. When I accelerate my O2 readings are 0.00v untill I let off of the gas. I believed this was due to a bad 02 sensor so I replaced that, now car runs better but the 02 readings are still 0.00v. Also when I reach full boost at WOT theres a loud clank noise and the 02s spike a little for that instant, I have no clue whats causing all of this but im about to take it to some diagnosis guy and spend some $$ but before I do that can anyone help me out here?

Thanks alot
-Randy

 

[99gst_racer]

OK I had this problem for somtime now, My car runs fine, it doesnt stall, but it is not as fast as it should be. When I accelerate my O2 readings are 0.00v untill I let off of the gas. I believed this was due to a bad 02 sensor so I replaced that, now car runs better but the 02 readings are still 0.00v. Also when I reach full boost at WOT theres a loud clank noise and the 02s spike a little for that instant, I have no clue whats causing all of this but im about to take it to some diagnosis guy and spend some $$ but before I do that can anyone help me out here?

Thanks alot
-Randy

You might need to invest a little $ in your fuel system. You have a higher flowing exhaust, intake and you're running 4lbs. more boost than stock. You might need to compensate for that increased airflow with a 190lph fuel pump, injectors, regulator, and fuel controller..... Just my .02.

 

[95TSiNewbie]

get a fuel pump or re-wire and it will help..... then injectors and an afc to actually start tuning for better performance. At 14psi, your stock fuel system wont keep up.

 

[/\G]

Thanks for your advice everyone, so what im getting at is I need a better fuel system. But does anyone know what that clank noise could be, it only happens when i hit full boost under harder acceleration someone told me it might be the BOV oppening to let some air out but I dont really know?

 

[95TSiNewbie]

Where does the sound, sound like its coming from?? Could be a lot of things.

 

[/\G]

im not too sure where the noise is coming from but its like a metalic clank/pop sounds like its coming from the left side of the engine bay when facing the front of the car. When the noise accures the boost reading on the gauge drops a few psi then goes back up for an instant, also the 02 readings spike up on the logger. I dont know if that gives you any ideas but there you go
thanks alot

 

[99gst_racer]

im not too sure where the noise is coming from but its like a metalic clank/pop sounds like its coming from the left side of the engine bay when facing the front of the car. When the noise accures the boost reading on the gauge drops a few psi then goes back up for an instant, also the 02 readings spike up on the logger. I dont know if that gives you any ideas but there you go
thanks alot

Sounds like really rough detonation. Get a pump, injectors, and fuel controller ASAP.

 

[95TSiNewbie]

i agree...wouldnt hurt to change your fuel filter as well. Also check your plugs and make sure the look clean...no oil or anything.

 

[/\G]

ok I took my car to be looked at by a diagnostic guy and he said that the place I have been getting gas causes a lot of problems with cars hes dealing with. He told me that somthing in that particular gas is clogging my injectors. Now what im doing is using Moble gas for a few tanks and if things start to clean up a bit then I take my car back and he is going to flush out my injectors and my fuel rail with some special stuff. Hopfully he is right and this will get me running back to normal again but from now on no more Wawa gas!

 

[/\G]

I got my injectors and my fuel rail cleaned out and the car def runs way better, and the it idles sooo much smoother and its real nice and quiet, but my 02 readings are still 0.00v under harder acceleration??? and suppoesedly the popping/clanking noise came from a backfire in the intake manifold causeing the bov to open for an instant, that should have gone away.... it is alot better but it still happens just not as much??? my fuel trims are:

Low: 111%
Mid: 109%
High: 124%

...better then before.
Do you guys have any input? i just spent 140$ to find out i needed to use moble gas and another 140$ to have a car that runs better but isnt fixed. what else is there to do i thought going to a professional would be the end of my problem. please help me guys i think im gonna sell my car... how about a supercharged scion tc

 

[DSMatMSU]

wow, this sounds like exactly my problem....
my fuel trims are very similar to that, and my o2 drops almost anytime i give it gas... ive got a re-wired walbro 190..... im only trying to run 13 psi or so on my evo 3 16g.... i know i need injectors and an afc to really use this turbo... but i figured it should run better than this.... im kind of at a loss now, short of buying new injectors and an AFC....

 

[/\G]

do you think my fuel pressure solenoid might be leaking i have heard some where that it can have a similar effect.... how would i check that