454 EGR

[Buckethead]

Greeetings to the list from an FNG!

 

I have an '89 GMC C3500 with a TBI 454 in it. This truck gets used to pull the horse trailer, haul hay, and any other "real work." when pulling a heavy load or going up hill I get the stupid "check engine light."

 

I checked the codes and the problem is the EGR isn't responding. I replaced the EGR controller and the actual EGR valve. In spite of this I stil get the same light and code. I've been told that this may mean my EGR ports in the intake manifold are clogged. To check for this I manually opened the EGR valve while the truck was idling and the engine continued to run. Apparently, if the ports are clear the engine should stall.

 

So, have I been given good info? Is this likely the source of my EGR problem? Does anyone have anyother suggestions?

 

Thanks!

[contactspec]

I think you're on the right track. My 86 has been running sluggish and getting poor mileage. I tore off the Rochester and am rebuilding it, and pulled the intake manifold. Found a volcano of shale in the valley, shale build up in the lifter areas, and am WD-40ing the heck out of the upper section, to do the same on the block after I drop the oil pan.

 

I'm going to have the manifold baked and blasted, even though I got the blockage out-- too much air in thru the carb gasket has necessitated it.

 

My check engine light has not been lighting, but with my luck, the bulb has burnt out.