92 500E missing under heavy accel

[jeff (moose)]

I have been dealing with an intermittent stumble under hard accel at highway speed that has me searching the data bases and finding actuators mentioned but no diagnosis or troubleshooting guidelines.

Could someone give me a hand? Thanks in advance.

I have recently found a loose connection (intake air temp) and repaired it and repaired the A/C blower motor, polished , glazed and gave her 3 coats of Mother's paste wax. She is looking hot and running fine but this stumble is making me look at the bottle of Hemlock and considering it for tonights cocktail. I should note that there is a slight noise from the exhaust that may be a loose exhaust shield. Please help!!

[jeff (moose)]

I thought I read something, somewhere, a long time ago that there was a wide open throttle sensor that can cause this on a 500E but I can't find anything on it.

[FLYNAVY]

I think your 500e may still use a throttle position sensor, and yes this has been known to fail. Either way, it sounds like you are having a problem with transient fuel enrichment, so it could really be a number of things. Have you taken a look at your MAS to make sure it is working properly? It wouldn't necissarily be the most likely culprit for this problem, but a lot of owners have had problems with these sensors at higher mileage. I know its a common problem for the C43/m113 community, and I would guess the same for the m119 types

[jeff (moose)]

I will look for a TPS. I assume it is a 5 vt. reference device with .5 being idle and 4.75 being WOT? I do know that you test it with a volt meter and look for a smooth tranition from idle to WOT and back down.

Is there a way to test that MAS in a situation such as this?

Thanks in advance

[300EVIL]

The TPS is buried in the throttle actuator under the intake manifold. If that's your problem, big $$$$. I'd look at the ignition side first. This sounds like a spark problem to me. You should plug it into a scanner and see what codes your getting. If your near Lake Geneva, WI you can drive on down and I'll run the codes for free.

[Gen3Benz]

Originally Posted by 300EVIL

This sounds like a spark problem to me. .

me too.
How old are the plug wires?

[jeff (moose)]

OE

I will get the trusty Fluke meter out and give them a good look this weekend

It makes sense that the spark would follow the least course of resistance.

I guess I will give it a new set of those expensive spark plugs while I am there.

Thanks again

[Jim's500E]

No, no Jeff...use the plugs the motor calls for...the OE Bosch ones are fine. But sounds as if the problem may lie elsewhere (?)

[jeff (moose)]

It was a joke. the OE Bosch plugs are dirt cheap. All i need is someone to make the time to get them done that is the problem.

Jeff

[Jim's500E]

Oh ... LOL ...thought you were going to sport Platinums for some odd reason.