mytele

I have a 99 Chevy Suburban 5.7 Central Port injection. I would like to know what kind of damage could happen to my car if I drove the car with a completely obstucted Fuel Return line. I have read that in testing the fuel pump you pinch the return line and start the car and run at idle briefly and read the max. presure. What would happen if I dove the car? I would like to know what I'm looking at replaceing.

dewey

On a deadhead pressure test, I use key on engine off, I don't start it. If you tied to start it, it would probably flood the engine and wouldn't run. It could also damage the fuel pump, in my opinion, if you tied to drive it. I'm not sure what all it might damage.During a deadhead pressure test, the pressure goes to about twice the norm. A symptom of a clogged return line is the pressure going through the roof.I think trying to drive it that way, is a bad idea.

How do you know the return line is clogged? You could take it loose at both ends, try to blow air through it, pour carb cleaner or something through it, or replace it.Some of the others may have some better ideas.

mytele

Thankyou for your reply. The mechanic who did the diagnosis of my fuel pump left the clamp on my return line. The car was release to me with the clamp still on. I drove the car back home and all kinds of things started failing, Fuel pump and a different mechanic saidthe central port injector module failed and was dumping fuel to all the cylinder. Of course he did'nt know the clamp was on either. It wasn't until I removed a new fuel pump, which I put in, and noticed that the plastic fuel line off the pump was ruptured. Then I noticed the clamp was still inplace. I was wondering what other damage I can expect.