almost no throttle response

[1cln91]

91 turbo, awd, 5spd, my car has almost no throttle response, auto tech teacher thaught that cat might be clogged causing intake to not pull air in, cut off the cat, looked brand new, turbo spins, intercooler isn't clogged, it just wont suck in air, brand new k and n air filter, maf isn't clogged up, has brand new ecu, car sat for roughly 3 years, me and my teacher have no clue what could be causing this. I'm new at dsms so any help would be greatly welcomed, thanks.

 

[anubis]

sounds to me like it's either one of two things: you're not getting enough air, or you're not getting enough fuel.

if it's an air problem - make sure the maf is plugged in. check your compression. check your your timing. see if the throttlebody is plugged up. do a boost leak test.

all of these checks can be found on vfaq.com. you should go there and get yourself familiar with that site.

if it's a fuel problem - it could be anything - bad fuel pump, clogged fuel filter, bad fuel pressure regulator, or bad/clogged fuel injectors.

good luck and keep us posted.

 

[1cln91]

I know its not a fuel issue because the filter in new, fuel rail has been removed and cleaned, injectors have been put on a injector refurbisher, and fuel pump runs proper pressure, maf was pluged in, timing is perfect, ran a vacuum test and no leaks found, havent done compression test but 99% sure it's fine, i read in my chilton's manual about the tps sensor and i realy think it might be that because the car runs the same with it pluged in and dissconected, could that be it?

 

[anubis]

absolutely.

here's a vfaq for testing/adjusting your tps.
http://www.plymouthlaser.com/tps.htm

 

[Tantrum]

Even though the maf isn't clogged it could still be going bad when it comes to it's metering capacity/circuitry..

 

[1cln91]

im going to check the tps today in class and hopefully thats it bescause i have a spare that i know works and i'll check the maf to make sure it works.

 

[dedlewamp]

Also check your base timing to see if it is set correctly.

 

[1cln91]

tps and base timing was fine, maf seemed to work properly, hard to tell with supratic idle (using snap-on Modis frequency test), was told by a friend that the vacum ports on the top of the throttle body could be pluged causing the unstable idle, is this correct? Am going to clean egr vavle and see if that will help also.

 

[1cln91]

Found the main problem, 3-4 teeth off timing, replaced timing belt and get the engine timed correctly, runs pretty good now, rpm's fluctuate slightly, and runs rich, o2 sensor was replaced, working with local shop tomorrow to get the final bugs worked out.

 

[1cln91]

Wrong ecu getting correct one on monday