I have not put the cleaned EGR valve back in yet, I was waiting to see what you thought? I can't seem to find a screened EGR gasket locally in the San Francisco, CA area? So I may have to order on line somewhere. Do you think I should start it up without the EGR installed to blow out any extra deposits? Will this damage the engine? But planing on reinstalling maybe tomorrow morning just to see how it works.

What causes some much carbon build up? Do you think that if the idle smooths out that everything then should be okay? What else should I look at to verify that the car is not running to rich? I don't want to damage the new Catalytic Converter.

Again thanks for all the help. I'll let you know how the engine runs after I put the EGR in.

 

The design of the EGR systems on these engines leaves a lot to be desired. Carbon buildup is notorious.

As far as starting the engine without the EGR valve, YES!! First, plug the port that runs to the intake. Second, get a really long brass pipe cleaner a little bit larger than the exhaust supply port and work it into the port as far as you can. Then start the truck. Repeat until you are satisfied. One more word of advice on this, do it outside with the truck facing away from anything you want to keep clean.

 

Ah, life is good again, well at least for now. This morning reinstalled the old EGR, without blowing itout, because car was in the garage, but I did vacuum the ports first. Took the car on the highway it seemed very responsive when I gave it the gas and when stoppeditidled smooth. I'm going to install at the minium the Tomco Screened EGR gasket and maybe the EGR valve.

I thinking of using the Standard Motor Products EGR valve from RockAuto.com it's $80 compared to $140 for AC Delco. What do think about the Standard Motor products?

Now that we've done all this trouble shooting do you think after replacing the Tune-up parts, O2, Cat, and (will install screened EGR gasket) will this solve not only the ruff idle but the poor fuel mileage? How can I be sure it's not runing to rich? I don't want to damage the new CAT. Went should I pull the spark plugs and inspect? I also have to take the car in for a smog test, will the results show if it's runing to rich?

Again thank you very much for all your support.

 

Never used anything SMP. I do not think it would be a problem though (if you need it).

If the EGR valve is hung open, it will definitely result in lower mileage. As far as whether it is running rich or not, you could pull the plugs again in another 100 or so miles and have a look. They never looked fuel fouled, but carbon/exhaust fouled.

A smog test would definitely show if you were running rich.