ALRIGHT THE CAR RUNS NICELY WHEN I FIRST START IT UP AND RUN IT BUT ONCE IT STARTS WARMING UP I BEGINS TO HESITATE WHEN I KEEP THE THROTTLE IN THE SAME POSITION IT WILL STUMBLE AND LOOSE POWER THEN REGAIN IF IM IN FIRST GEAR IT WILL HESSITATE AND THEN START BURNING OUT. IS THERE ANY WAY TO TEST THE THROTTLE POSITION SENSOR. I JUST SET IT AND PROBLEM DID NOT GO AWAY. COULD THE EGR SOLENOID DO THIS???

 

That could be a tough one to help figure out without being there. You can test a TPS, set your voltmeter to read 0-5v then backprobe the signal return wire (the one taking the message back to the ECM), ever so slowly open the throttle (key on, eng. off) watch the voltmeter, it should sweep smoothly between approx. 4.5v-.5v. If at any point in the sweep the reading acts erratic, replace the TPS. Shouldn't be the EGR which shouldn't hurt a thing if it's open @ cruise condition (and you can't hold a cruise, right?) However, devise some method of disabling the EGR (blockoff gasket works for a temporary), then run it and see if you still have the problem. As for good cold operation, sounds like this is a "closed-loop" problem so check the O2 sensor, check the temp sensor, and check the ECM for any trouble codes which might help narrow the search.

 

replaced TPS and MAT sensors did nothing could it be a vaccuum problem i plan on putting these heads i have on this weekend so i will seal it up real good do you think it could be plug wires??
ill try that O2 sensor too thanks for the help

 

Probably not the plug wires which should also be a problem cold. (And would be much worse under acceleration than cruise). MAT is O.K., check the CTS (or just replace it, they don't cost a lot). If you have vac advance, check the diaphragm. Also (I have no idea what you're running) if your distributor has centrifugal advance, grab the rotor button and give it a little twist left or right. In one direction it should move smoothly about 1/4" then snap back when you release it. Keep us posted. It helps us all to learn the final diagnosis of a problem.

 

i AM RUNNING TUNED PORT INJECTION WITH THE STOCK DISTRIBUTOR FROM THE 92 I REPLACED THE CONTROL MODULE IN THE DIST. A LITTLE WHILE AGO I WILL TRY THAT CTS AND THE O2 BUT i WOULD THINK THAT FOR THE O2 I WOULD HAVE GOTTEN A CODE. WOULD IT BE THE MAP SENSOR IS THAT POSSIBLE I DONT GET IT CAUSE THE PROBLEM SEEMS TO GET WORSE THE MORE THE CAR HEATS UP ITS NOT LIKE IT JUST STARTS THE PROBLEM STARTS OFF SMALL AND PROGRESSIVELY GETS WORSE THE WARMER IT GETS

 

A MAP sensor can give you driveability problems like that. It's difficult to explain the test for which you'll need both a high impedance DVOM and a hand-held vac. pump. First take a visual of the entire vac.hose and wiring to the MAP and check the body for defects. On the O2, most conditions will set codes but don't bet the farm on it. It's more important if you can find out what it is communicating to the ECM (scanner). Is it asking for more fuel than it should? Is it responsible for a too lean condition?

 

how do i check that and what asks for the fuel what effects the ratio is it. i know you can check the ratio through the o2 sensor but the map sensor is what tells it how much fuel to deliver right?? anyways why would the engine heating up effect that??

 

The unit in charge of keeping the ratio correct is the ECM. However it is just the decision maker, it needs input on the operating conditions, which it gets from it's various sensors. The MAP's job is to tell the ECM what the vacuum condition in the manifold is, using that info and the TPS helps the ECM know how much of a load the engine is dealing with. The critter most responsible for asking the ECM for more or less fuel is the O2 sensor. It is giving the ECM the facts about how rich or lean the current situation is and the ECM adjusts from there (many times a second). As for the ratio; it's not arbitrary. The ECM is seeking stoichometrical efficiency (14.??:1) during almost all normal driving conditions. Bottom line: any sensor may be "lying" and the ECM will try to run the car with this faulty information. Or any controller (the components the ECM uses to effect changes)may not be responding properly to the commands.
Sorry to digress. But back to my initial comment about driveability being a dog to diagnose like this.

 

WOW whatever ill try the cts and o2 i think thats what your sayin. thanks for the help ill tell you if it helps tomarrow