Gary - KQ6RT rambled on about something in :
But, in that case, isn't there a regulator somewhere, to make sure the pressure stays around, in this case, 18psi? Same probably holds true with the '91 that the original poster mentioned. Any extra fuel will get rerouted back to the tank, IIRC.
Only way to know for sure would be to check a manual. (Joe might know too...)
NOI
I just dug out the old shop manual for my Blazer. Here is what I have found. The pressure regulator is located on the inlet of the TBI unit. There is no access port to measure the regulated pressure. The fuel pump is supposed to deliver pressure between 13 - 18 PSI. In order to measure the pressure you need to install a Tee fitting on the fuel inlet to the TBI. The regulator is supposed to regulate pressure between 9 - 13 PSI depending on engine load.
Thinking back, I was able to tell when I had a fuel pressure problem with mine just by watching it run. The "Injectors" actually mount above the top of the TBI and spray down the throat like two sprinkler heads. If you see a nice even mist you probably have adequate pressure. If you see the nozzles dribbling fuel out you have a problem. My experience has been that when the pump goes bad, your car will be undriveable. Pressure just slightly below the proper range is usually remedied by installing a new fuel filter. I hope this helps. - Gary
Thanks for the responses. My manual shows the regulator inside the throttle body assembly and yes the injectors (2) sit above and spray down. The problem is that the fuel pump is delivering zero fuel - the electrical circuit checks out so I have to conclude that the pump is shot. The only psi rating I could find was in the TPI & MPFI section and that was 34 to 39 PSI. Guess I'll call around when the shops open in the morning and see what I can find for replacements. Thank you.
Jon
No, not even a whisper from it. I can easily suck fuel through the line though (using a vacuum pump :-) ).
Jon
Jon Greene rambled on about something in :
Hmmm. Check the relay?
NOI
yep, relay works fine - voltage where it's supposed to be on all wires connecting to it.
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