Luis de Prat

Car has 146K miles and this problem keeps rearing its ugly head on and off. My father is the regular driver and he doesn't push it at all. Then I get in it and drive the heck out of it and it will begin to hesitate at full throttle.

Also, at startup it sometimes feels like the engine will die out if I give it gas. Feels very week. Then I pass some magic threshold by slowly accelerating and the engine picks up speed.

Some past history:

Airflow Meter replaced with new unit at 124K
Full belt job and water pump, chain tensioner at 124K
Ignition Control Module replaced at 127K
New alarm control module
Spark plugs replaced about 3K ago
New OE Oxygen Sensor just replaced
New Bosch 14V voltage regulator just replaced

There is no foul "rotten egg" smell or noises that would indicate a clogged catalytic converter.

Occasionally, there will be a faint gasoline smell in the cabin after the car has sat overnight.

I'm completely at a loss as to where to begin looking for this problem.

TIA

Daniel Dudley

If you are saying that the problem gets worse the more you drive, I would replace the fuel filter, and check to make sure the screen in the gas tank isn't clogged. If there is a lot of dirt in there, then the more fuel you demand the more dirt gets sucked up. Parking lets the dirt settle back to the bottom of the tank. I assume you have checked for vaccume leaks, etc..

Luis de Prat

Thanks Daniel, forgot to list the fuel filter which was also replaced about 3K ago as preventive maintenance. Might need to check the vacuum hose clamps for tightness... Which ones should I look at?

jharding

Your Throttle Position Sensor (TPS) is probably bad. There is a voltage test in the Haynes manual, however, I have not been able to get the same readings even with a new switch. With the engine off turn the throttle cam slowly. You should hear a click as you move the throttle cam just off the closed position. If you don't hear a click, the TPS is probably junk. The other problem is water can build up inside and short out the electrics. So even if it clicks it could still be bad. My vote is to just replace it with a new, oem switch. Some people suggest to drill a small hole in the bottom of the TPS so water can drain out. If you do that just make sure you don't drill through something important! :-)

Luis de Prat

The TPS clicks with the engine turned off. This car seldom if ever sees rain, but I guess the TPS could still be at fault. I'll check out that test in the Haynes manual.

Interestingly, I drove the car hard the other night and it hesitated when I started driving it, but later on it drove normally, even when I pushed it hard.

Mark944na86

A few years ago, I had an intermittent hesitation problem on my 86 NA which cleared up after I installed an MSD 6A ignition and Blaster coil capacitive discharge set-up. I also put in new plugs and replaced the wires with Magnacor ones, as I recall.

Anyway, the car ran very sweetly after that, it was noticeably more responsive -- and there was no more hesitation problem (which was an unexpected but welcome bonus.)

Of course, all of this may have absolutely no bearing on your problem. Cars are like that...

BTW, my current performance upgrade is an 89 S2. (Works even better than than the MSD kit! :-)

-Mark

Pitou

I know, the problem is not your right foot.....

Melchior

The faint fuel smell may be your Fuel Pressure Dampener or Regulator. Check the archives to see how to test both of these. These would also effect your start and hesitation problem