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EGR Valve

My jeep has had a funny idle when warming up on a wet day. It's always been like this. I bought it new and the mechanics said that it was just cold blooded. Now it's 16 years old. It runs so bad after a wet day that I had to do something. I unplugged the hose to the EGR valve and that seem to do it, but that isn't a real fix. Where are some good places to look for this problem. (I don't mean the internet) I mean the parts on the jeep. It is time to replace the O2 sensor? I've watched the electronically controlled mixture pin move in and out as it should, and there's no extra gas dripping down the inside of the carburetor as well.

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Replacing the O2 sensor is a good idea, especially with a Jeep that old. However, usually, a poor running vehicle on a wet day is ignition related as electicity doesn't efficiently conduct if moisture is present. You might try swapping out the coil for something stronger or going with an MSD type mult-spark discharge. A good tune-up with quality parts like Standard or Mopar is a good idea too. It could even be that the distributor cap doesn't seal well to the distributor because of a flaw in the contact surface on the distributor and it lets moisture in. It could be many things, but I'd look at the ignition system for what ails this type of condition.

Reply to
Big Daddy

If unplugging the EGR has an effect on the idle, then the EGR is a bad one.

Sounds like it was a defective one from day one too.

Other than that, I always suspect carbon tracks inside the distributor cap first for wet running problems and leaky wires second.

You can test the wires easily, at night get it running and use a spray bottle to mist the wires with water. If you get a light show, the wires are worn out and leaky.

A good strong light or direct sun is handy for looking for carbon tracks inside the cap, they look like faint spider web marks and can be white or black.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

snipped-for-privacy@Gsd-Co.Com wrote:

Reply to
Mike Romain

Check The CTO (Coolant Temp Override) valve. It is the job of the CTO valve to block vacuum from reaching the EGR until the engine starts to warm up. If a vacuum gauge shows vacuum reaching the EGR valve when the engine is cold, the CTO is not doing its job. The engine is not supposed to handle the EGR functioning while the engine is cold. CTO = about $25.

Reply to
David Harmon

Good point, but the EGR line also has to go through the thermostat in the air filter and vacuum should not be present in any of the EGR lines until the engine is at speed.

It uses a 'ported' vacuum signal.

Now his plumbing could just be plain wrong with a manifold vacuum tag on the wrong place on his CTO valve....

Mike

Reply to
Mike Romain

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