Poor engine response after acceleration

[trevorzucker]

Hey there,

I recently got my hands on a N/A 86 944.

A few days ago, I power washed the engine bay (I covered the battery), and noticed a strange issue.

Whenever I bring the engine RPMs above 4000, the car becomes very laggy. If I put it in neutral, the RPMs drop extremely quick and the engine stalls. The only way for me to prevent it from stalling is keeping my foot on the gas to maintain 1000 RPM (when I do this, the exhaust sounds extremely spuddery, almost like I'm not firing on all cylinders, and I smell gasoline). After I drive for a bit or sit in neutral with my foot maintaining RPM, the RPM will shoot back up and everything drives normal again.

Does anyone have any suggestion on what could be happening here?
I inspected spark plugs and spark plug wires to ensure there is no moisture. I also live in an extremely dry climate and I am fairly certain all moisture has evaporated by now.

Thanks.

[walfreyydo]

Check:

Spark plugs/wires/plug gap - it sounds like one of the cylinders is missing, recommend checking all your plugs and wires with a spark tester. Verify all are firing, especially when the problem arises. Verify they are gapped correctly

DME temp sensor (the blue top one near the intake manifold) - when it goes bad it could be sending a signal to the DME that the engine is cold, thereby richening the mixture.

AFM repair/refurbish - there is an actuator arm which has contacts and gets worn. If the contact point is slightly adjusted, it can have a fresh conductive surface to connect to.

Throttle Position Sensor (TPS) - sometimes the sensor for wide open throttle can stick and cause issues with fuel mixture or confuse the computer.

Vacuum leak - usually results in a surging idle or a car unable to idle.

Stuck injector - less likely, better to check the above first before going down this road.

All of the procedures to check the above is on clarks-garage.com recommend reading through them and testing

[TibetanT]

Hello There:

When you purchased the car, did the previous owner provide you with any records?

If there are records, read through them all and make note of when the last good service was done. Such as: 1) complete tune-up, 2) when was the last 50,000 mile service done (water pump, engine seals, timing belt/balance shaft belt) Fuel Filter changed, oil change service, entire ignition system upgrade (plugs, cap, rotor, plug wires) and fuel injection system tested, etc., etc., etc.?

From what you describe here, sounds like a fuel enrichment problem, but could be something else.

If the timing belt, balance shaft belt and front-end has not been serviced in a long, long time then now is the time to get this done. If not, you may end up with a broken timing belt and some real serious expense to get the car running again.

Sorry but I have to ask, "why did you power wash the engine bay" ?

You may have gotten some electrical components wet that do NOT like getting wet. <<

Hope this helps and "Good Luck" with your car.