Keep busting Fuel Press Regulators...any ideas?
 

I have replaced my AC Delco Fuel Spider twice now, and both times the pressure regulator has gone bad in just a couple of days and leaked fuel in the plenum :(

Am I doing something wrong? Fuel Pressure is 56-58 psig, vacuum is steady 20" running.

Ordered a Standard Motor Products injector today at the recommendation of a respected local 30yr Chevy mechanic. Hope he's right!

Do the nut kit too!!! with replacing the injector this many times, that will have to be replaced.
they are like 60 bucks, 2 5/8th" flare nuts on the back of the intake once you have the plenum off. and they are held in with a bracket and a torx bit.
They fit in the intake pretty tight, getting them out can be a pain, getting them to seat fully in the intake is even more interesting. its almost easier to take the o-ring off the nut kit where it goes into the intake, put that in the groove on the intake first, and then put the fuel lines in.


I also found that putting the injectors in, that is the easiest way to get the fuel lines into the injector... after struggling for like 15 minutes to get them in, i took the o rings off the fuel lines, put them in the injector first, then the fuel lines just snapped into place.

Nut kit is new, and pressure tested them good. Thanks for the suggestion. I looked in the top of the plenum last night and there were little gas puddles. My spider is under warranty but this is getting old :(. Thanks.

Ok, got new spider in. It pressure tests out good. Just took me three of them. Thanks for being patient with me. Now to try to diagnose my other issue (different thread)!

Thanks, you guys are super helpful.

If the fuel pressure regulator diaphragm keeps blowing out, there's only one thing that will cause that.... a restriction in the fuel return line, (the 5/16" line that goes back to the tank). If the diaphragm is exposed to more than ~75psi, it will rupture.

Thanks Captain Hook, I think I blew one of them when I was pressure testing the fuel return line and pressurized it by pinching off the return hose by the fuel filter. One of them was bad out of the box, the other one I'm not sure what happened. Rookie mistake on the one.

I've pretty much found my rough idle I think. I have only 95 psi compression in cylinder 5. Squirted some oil in it and it only went up 5 or 10 pounds. I did the dollar bill trick at the muffler and it didn't try to suck it in at all (intake valve?). Gonna try a pressure test next.

This **** blazer is driving me nuts. If I don't figure her out soon she's gonna get sold! I love her, but I forgot how much trouble these first gen CPI's can be.

Thanks again.