I have a 1991 convertible, bone stock, 140,000 miles.

A few weeks ago it was really hot out (85-90), I drove my car about 10 miles, parked in a driveway, then 10 minutes later started the car fine and drove down the road. I got about 50 feet when i would step on the gas and the car would start bucking. i was completely losing power if i pushed on the throttle. it was having trouble revving past 2 or 3 grand while in gear. kinda felt like i was hitting the rev limiter. after about 5 minutes of blipping the throttle and bucking down the street, the problem went away, and everything was good.

Yesterday I had the same problem. It wasnt too hot out (75-80), i drove about 40 minutes, parked my car for about 20 minutes, when i left my driveway i didnt get 50 feet down the road when the same thing happened. It went away by itself again, and there were no more problems.

I was wondering if anyone else has had this happen, and if they were able to figure out what the problem is. Its kinda hard diagnosing an intermittent problem like this. Hopefully I can fix it before it becomes a big problem.

 

Very interesting; a friend of mine's car has excatly the same problem. I'm curious as to what it is.

Perhaps check the AFM? Could the ECU be going insane?

 

The ECU going insane was on my list of possibilities. First off I'm going to replace the plugs and wires. I need to get that done anyway.

 

The most common cause of hesitation on our high mileage cars: The short range TPS.
When the variable resistor wears through, the ECU starts seeing the drop outs as "idle" when you're at part throttle, and gives fuel cuts.
When this first happens, it can be heat sensitive.
-The golden test:
Unplug the TPS connector.
Clip a cheap analog (needle type) VOM on the green & orange pins.
Set it to the 1K scale.
Hold off the throttle & work the short range TPS plunger in & out.
You should see a smooth sweep from ~0 to ~5K ohms.
Any bad spots or drop outs in the stroke - it's bad & will give fuel cuts at part throttle.
(Before you toss it, try spray contact cleaner between the sleeve & plunger.)
- Then set it:
Find the fast idle (warm-up) cam & back it off so the throttle sits on the hard idle stop.
Adjust the setting to 1K ohms.
While holding off the fast idle cam, open & close the throttle a few time to see that the 1K setting repeats.

The upper (long range) TPS is self adjusting.
You shouldn't have to mess with it.
Its job is to tell the ECU how to run the MOP.

 

Thanks for the advice sureshot. Thats exactly the info I needed. I will test it out and get back to you if thats the problem.

 

Also make sure that the plug located on the back of the water pump housing is clean and connected properly.I had this problem once.Good Luck