EGR vacuum solenoid melted! ....Why?

I have an '89 XJ w/. the 4.0. I recently had problems w/ it running like garbage then not at all. I discovered that the vacuum line coming off the throttle body and into the map sensor had cracked, then fell off. I replaced the vacuum tube and my beast was up and running again.Over the next 50 miles or so the engines performance became weaker and weaker.

I had a chance to look things over today and found that the EGR vacuum solenoid was melted as well as one of the vacuum lines coming out of the air box. I opened the air box and it had a mixture of oil and moisture in it and looked as if the air filter was slightly burnt on the rear side where the vacuum lines enter the box.

Anyone have an idea what I have going on with the EGR system?

Thats weird that it looked burnt. I have oil in my airbox caused by the common blow-by issue. Maybe fuel vapor or soemthing caused it to burn?

1985xjlaredo said:

Thats weird that it looked burnt. I have oil in my airbox caused by the common blow-by issue. Maybe fuel vapor or soemthing caused it to burn?

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Hmmm..the "burnt" area on my air filter may just be a result of blow-by.Another thing I noticed when openig the airbox was how much it reaked of exhaust.

Don't see too many people jumping on this one...I kinda figured it was a rare failure. I checked Advance Auto and they don't carry an EGR vacuum solenoid for my Jeep..so....I suppose I'll go throw some more money at my local Jeep stealership.:flamemad:

Problem solved.........

I ended up replacing the EGR valve, EGR transponder, and a host of vacuum lines. Threw a tune-up on it while I was at it. I fired it up today after performing all this work and it still ran like crap.....Then a light bulb lit..I removed my catalytic converter, peered inside of it, and realised immediately what caused all of my issues in the engine bay with melting my EGR plumbing. The cat was atleast 90% clogged..this created an immense amount of backpressure and exhaust heat. This heat was then backfed into my EGR plumbing pretty much wiping out anything that wasn't made of steel.

My cat is now, ahem......completly clean. My pig is running like a raped date again and I'm now shopping for a high-flow cat to replace my "cleaned" cat.