Approx. 230k miles. Brand new plugs, wires, cap and rotor, main fuel pump and filter, MAF sensor, ignition coil, throttle position sensor, battery. Idle is most always pretty rough and throttle is slow tonrespond upon pressing it. Also, usually when on the freeway, when I punch the gas to a pass a car or climb a hill, the car will not downshift and there is very little power. But, if I stop the car and shut it off for a few seconds the problem seems to correct itself, at least for awhile. Any clue what the problem may be? My guesses now are either: fuel pressure regulator is shot or ECU isn't functioning properly. I just want my old lady to run right again.

 

thats a lot of new stuff. any of which could be bad out-of-the-box, since new also means untested.

when did these symptoms start? was the throttle body and idle air controller cleaned? have you been through the idle adjustment procedure?

what sort of shape are the vacuum and air hoses in ? air leaks in the intake path between the MAF and engine, and for that matter exhaust air leaks between the engine and o2 sensor, can cause all sorts of funky problems.

 

The symptoms began after the jumper cables were crossed after jumping my dead battery (not me, friend who was helping). The first problem I encountered was the ABS system blew a fuse. From there it was the fuel pump, then this hesitation problem. I was about to embark on a 2k mile long road trip so wanted the car to be in top shape, which was the reason for replacing all of those sensors (did a lot of troubleshooting from this forum).

I cleaned the throttle body when I replaced the TPS. All of the vacuum lines look fine. Have checked for leaks in the exhaust or around the O2 sensor.

Is there a possibility crossing the jumper cables may have screwed up my ECU?

 

try cleaning the idle air control valve

 

reversing polarity of the power supply can damage all sorts of electronics, yes. the ECU and ICU on these cars are both computer boards, using 8048 or 8051 industrial processors.

 

Any update? I am having a similar issue 93 wagon non turbo-- Slow, inconsistent acceleration, car drives like a Buick now :/

Noticed the issue after she over heated, belts got tripped up causing my power steering belt to... umm fly off..

Drive belt and power steering belts were replaced, coolant was filled. Car seemed to drive alright at first but now I am starting to get nervous.

Questions))))
1. Could it be that the engine timing is off? I think the timing belt was removed to replace other belts...
2. OR maybe the kickdown cable just needs to be adjusted? TPS cleaned? I didn't think my 93 940 had a tps ( I have only had car about 2 months)

I also will look into cleaning idle air control valve.. though the car idles fine..Seems a tad slower than usual (might be only in my head.)


Mine is a non turbo if that matters any.. extra non turbo now
Thanks for any insight you all can give.

Much appreciated,
Eric

 

Seems like a lot of people show up here and then disappear. Nothing new or surprising.

I suggest you start a new thread.

 

the timing belt does NOT have to be removed to swap the other belts... the other belts are external, the timing belt is behind the plastic cover on the front of the engine.

 

Dont even **** around with the IAC.

Poor driveability can be a hundred different things. You need to start with the basics like making sure there are no airleaks, fuel pressure is perfect, compression is good on all 4, ignition components are all in excellent condition, timing belt is perfect, and mixture is correct.

Here we go.....

Any codes?