delsolintegra

This may help some people. The car is a 93 Del Sol SI with auto. The problem was with the A/C on and stopped at a traffic light the car had no throttle response to pull away. The longer I sat at the light the worse the idle decreased and stumbled. The second I turned off the A/C compressor the engine came back to a strong idle. I figured it was load related to the engine.

Turns out it was the MAP sensor gasket. It's a flattened rubber gasket sits recessed in a groove below the MAP sensor. The MAP sensor has a flat plastic bottom and just rests on the gasket. Must have been the original rubber gasket.

The best part is I got a replacement O-ring at ACE Hardware that fits and cost about 60 cents.

Here's some pics of the MAP sensor location and the part number.

Maybe this should be a sticky.

tony_2018

Any replacements before this incident?

delsolintegra

I've had the car about 6 years, no replacement on the MAP sensor that I know of. The wording on the sensor is "Sensor Assy MAP, 079800-2500 DENSO, SV PS-30". Looks factory to me. The gasket was flat and flush with the throttle body housing, even looked like a little green corrosion on the aluminum by the gasket. Might be a sign of air leakage.

Other items I have replaced up to 2 months ago were the coolant temp sensor which cured a hot engine restart problem. Also the cap, rotor, coil, igniter, plugs. A year ago I did the TPS.

I try to fix one thing at a time so I can tell what finally cures a problem.

joey1320

Kind of weird you were not getting some type of vacuum fault but good find bro. If you didn't, I would suggest coating the new o ring with a bit of top grade silicone grease to prevent it from drying/cracking prematurely.

delsolintegra

I forgot to mention I did that too.

As these cars get older it seems like the sensors performance deteriorates enough to badly effect performance but not quite bad enough to throw a cel.

I noticed that with the coolant temp sensor. I never got a code 6 but it must have been right on the edge of throwing it.

joey1320

Nice job!

oneheadlight

excellent work!! I've been having a similar experience, and been focusing my diagnostics on the stupid IACV (idle air control valve), but it isn't helping. You caused me to look at the MAP now. I too have seen where the part does NOT give a CEL (check engine light) but the part is still beyond performing well or at optimum! Tired of people saying "oh it's fine if there is no CEL" ya right.. Saw that on a couple of things, like the 02 and IACV!

I'll go over to ace/true value and get an o-ring.. I want to see what a 20 year old o-ring looks like on mine! I bet it's bad too! Nothing can last THAT long and still be in great shape!

again.. THANKS for posting this! It has helped me a lot!