landcrabmech

Hello all,

Have a question hopefully someone on here can help me answer.

I am currently working on a 1995 SL500. Problems I have repaired already are, 1- replaced engine wiring harness due to all insulation powdery and non existent in other areas. 2- replace valve cover gaskets and spark plugs.
3- checked and cleaned distributor caps and rotors (slight moisture in each).
4- replaced ignition coil on left fender.

Problem still occuring;
1- starts and idles without issue when cold.
2- while idling and warming up a small mis can be heard and felt.
3- when putting under load the mis is unmistakable and car sputters and dies.

When this happens it is really difficult to start or will not start.
I got it running again and drove up a hill to see clouds coming out of the tail pipe on the driver side.

Could the issue I am looking for be the catalytic converters are clogged, and it is stalling due to really high back pressure, therefor stalling the engine?

Or is the issue the crank position sensor?

I am leaning toward the clogged cat due to the symptoms, what do you guys think?

Scott

OCBroker

Thanks for your reply. I am still having the same problem. I have replaced everything except the converter and the computer control module. I hope you are right about the cats. For your info. I have replaced wire harness, throttle body, o2 sensors, crank shaft sensor, ignition coils, spark plugs, maf, voltage regulator, fuel filter, and idle control module. This is getting very expensive and still no luck. Please let me know.

landcrabmech

I will be attacking this on Sunday and will report back to the forum. I have a crank position sensor and cam position sensor on hand as well if this is not the problem.
What I see, is that the MAF is not getting enough air because the exhaust is plugged. Then the backfire I hear is not actually a back fire but a little explosion in the exhaust manifolds when a little oxygen gets in and helps ignite the fuel load between the manifolds and the cats.

Scott
Instructor of Heavy Duty and Commercial Transport Mechanics.
Vancouver Canada

salabellera

Hello,
I would likely look into the egr valve and egr vacuum selonoid. they are not expensive, consider age of the car vacuum connections are still functions.
Goodluck!

OCBroker

Thanks, I am willing to try anything at this point