poor acceleration

michael · #1 07-06-2003, 04:10 AM

for quite some time my car seems to be accelerating poorly at low rms. When I start it in the morning on the way to work I have to go uphill and it runs terrible I have to stomp on the pedal to get in the higher revs and it takes some time to get there. It seems like it's having trouble getting fuel or fuel pressure and it doesn't go away it just gets slightly better after a while. On occassion it runs well I can tell because sometimes when it shifts hard during hard acceleration it's like a slingshot like when I first bought it. I really miss that and I miss the full spectrum of torque that it used to have I drop quite a few $'s on performance mods and it's just going to waste because of this problem. I checked the codes and got 22,32,34 and 38 I changed the 02 sensor code 32 reset the comp and it won't go away 38 just showed up today. what should I change first or is it something not related to the codes. I tried a fuel filter, injection cleaning, cleaning fluid, plugs are only a few months old, cleaned throttle alternator and battery are fine
got a new catalytic converter air filter tranny is fine new front diff and tailshaft brakes aren't dragging and are new same w/cv's and wheel bearings. P.S. my gas mileage sucks please help and sorry so long. Thanks Mike

Landshark · #2 07-06-2003, 06:06 AM

i kinda have the same problem. i changed spark plugs, a coil (reports misfires on #1 cylinder if going up a hill on cold engine - didn't help), TPS, throttle body cleaned, fuel filter, air filter, exhaust (Stebro didn't help

).......

i'm thinking now it may be one of two things: knock sensors (cheap to replace) or a gummed up Idle Air Control valve (most likely). i may take it to the shop and have the throttle body/IAC cleaned real good and the knock sensors done at the same time.

Red Wolf · #3 07-06-2003, 04:12 PM

One other thing you might want to check are the vacuum lines for the IRIS valve. Basically, look under the intake manifold between the power steering pump and the alternator, there should be a vacuum line going from the underside of the manifold to a black plastic fitting.

Just last week, John / svx_commuter did a quick inspection of my car and found that the vacuum line for my car's IRIS valve was disconnected. We reconnected it and the car pulls a lot harder now in the sub 3,000rpm range that I normally drive it in.

Check out this thread for more info on the IRIS system:

The hidden 37 extra HP in a 92?

Hope it helps.

John

michael · #4 07-10-2003, 08:36 PM

I figured it out, I replaced my O2 sensor with a bosch universal and I guess it didn't agree with the car. I don't know if it's the sensor's fault because I didn't put a new one in yet I just disconnected the universal one but it runs great now. Did anyone have a problem with universals before would an OEM operate at a different voltage than a universal, please help.