Hello!

I have a 94 GMC Jimmy with the vortec 4.3 (same drivetrain as a blazer)
It is 4 wheel drive and runs like a champ, but here lately everytime there is increased load on the engine from towing, or heavy 4 wheeling, the EGR keeps going bad. The engine sputters and stumbles and blows out black/blue smoke. I know this is the EGR because I have replaced it 3 times now and it fixs the problem. However this last time I used some gas/fuel injection cleaner after i replaced the egr. It ran just fine, but when I pulled into the parking lot of work, it done it again.

Why is my jimmy eating through EGR's???

 

There is definately something wrong.

Have your EGR Electronic Vacuum Regulator Solenoid and your EGR Control solenoid checked.