Quote:
Originally Posted by porkface
the only "regulation" for the fuel pump is the MAS relay, which controls the pumps, ac compressor and has other functions. there is no pressure switch to shut off the pumps. the shutoff is because of a timer built into the relay to prime the system. the pumps stop until an ignition signal is received by the relay and then the pumps run again.
you do need to know what the fuel system pressure is when the car doesn't start. needs a special set of gauges to test. i can't relate to WHY the pumps are cycling 3 times and then no start. sound like a relay and/or another problem. keep in mind, you need to know if there is spark when it won't start. the MAS relay has no control over the ignition. good luck, chuck.
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OK, the fact that the pump is timed by the relay helps me understand the system a little better. So as mpolli indicated above, I need to at least take a look at that relay.
I haven't been able to troubleshoot spark and/or fuel delivery because of the intermittent nature of the failure. When I'm at home -- where I have a fuel pressure gauge, and an assistant to turn the key while I work under the hood -- the problem doesn't present itself.