Bob Kennedy

If you are good at diagnosing mechanical problems, I would appreciate it if you could read the few paragraphs below and give me your thoughts. Thanks.

I have a 1993 rx7 touring edition with 115k. I had a fire several months ago that did $7k of mechanical (non-cosmetic damage). It seems a fuel line leaked in the engine compartment. Since then my car has some major hesitation problems. Here are the details:

1- Car hesitates periodically but regularly while driving. It "feels" like it has no power at random times. Even if you floor it there is no power and the techtometer won't increase.
2- Car wont go over 100-110mph and it takes a real long time to get from 80-100.
3- Car runs extremely poor when its cold or for the first five minutes after being started. It runs poor after that too, but not as bad as when cold.
4. I think it is using more fuel than usual. I usually get 17mph, but am getting only 13 or so.
5. Muffler is original and rusty, even showing some small holes.
6. It had a compression test that came out good.


I am wondering is a clugged muffler and/or catylitic converter can cause problems like this. Sometimes (and even going back a couple yrs) the exhaust doesn't seem to flow smoothly from the tail pipe as you can hear poping noises. Problem is that I dont want to go on a fishing exhibition as I just recently spent a lot of money on the car and don't want to spend more and still have the same problem. I've taken it to a mechanic but he couldn't pin point the problem w/o doing lots of costly work/tests.

If you can help, thank you. My email is rj_kennedy@netzero.net

Bob

BinaryRotary

You may want to check all of your ground contacts. There are three principal contacts to check: one at the fire wall where a wire strip connects to the UIM, one on the front driver's side fender wall just below the fuse box in the same location and one on the engine block just above the oil pan lip on the driver's side. All should be scuffed clean of any debris with an emory board or metal nail file. Unless the ground contacts are good and tight, your engine will run wierd.

Tim McCreary

Disconnect the oxygen sensor and see if the hesitation stops occurring during cruise. It only provides efficiency under light throttle and cruising. Possibly replace with new if over 50K miles.

Grounding is the first and most important part. Run a ground wire from the negative terminal back to the ECU frame to ensure a good ground to the ECU.

Have you replaced the ECU?
Have you replaced the engine harness with a new or used one?
Precat or main cat may be blocked.
Reset your computer? (Pull battery cable and step on brake for 10 seconds)
Have you checked for ECU codes? **do this before resetting the ECU

Tim