Well the cat has been replaced now and the egr valve was causing most of the trouble...still getting a fluctuating idle...any other ideas?

 

Vacuum leak, air filter, fuel filter, in that order.

Replace all the vacuum hoses, replace the air filter, replace teh fuel filter.
After that, IAC.

Post up if your still having trouble.

By the way, welcome to the site. I wouldn't sweat an engine with that many miles on it. If she don't smoke while running, you'll be fine. I had one last to 286,000 miles before I totaled out the truck. Engine ran strong as an ox. It even had the puff of blue smoke at start up, valve seals.

 

I concur, as far as the valve seals there is a TSB for em, change to the corvette style umbrella ones and the problem is cured.


I had the same problem, did a tune up and cleaned the EGR and replaced the vacuum lines and its fine now.

224K is a ton of miles, how are ALL the fluids?

 

Hey guys..sorry so long! The truck has never smoked on me and now runs like new. The seafoam in the pcv and brake booster, and gas tank cleaned her out good....the stuff is amazing! I also flushed the radiator cause of the rust. It looks a lot better but I want to change the radiator asap! Now I want to try to get a little more torque out of her....any simple mods to free her up a bit???

 

Oh...milage is 204...not 224...my bad!

 

Mine has been doing the same thing. Since I have extra parts laying around, I started throwing sensors at it. Serious waste of time (glad I had the parts off a dead engine I am replacing for someone).

I finally gave up and hooked the scanner up.

Turned out to be the TPS sensor. It was stuck @ 68%! When I came back from lunch with my GF, the thing would not shift to 2nd until 30 mph, and 3rd @ 55 mph. And it shifted HARD! Anyway, threw it on the scanner and checked the sensors out, at idle, it searched high and low to get the desired idle speed but never could. Took out the TPS and put a replacement in, had a similiar problem, just not as bad. A little tweaking on the butterfly screw to get the TPS to 0% and boom! Smooth idle again! This truck had a sticky EGR valve and someone apparantly turned up the screw to compensate. Watched all the sensors for about 10 minutes on the scanner and everything is working good now.

 

YEp, seafoam is good stuff.

The best way to free her up is via a cold air intake, and header back exhaust system. Muffler at the minimum, but about all that gets you is a seat of the pants feel and more noise.