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Fuel pump problem Helpppppppppp

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fishnxtc

Freshman Member
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88 vanden plas. I can hear my fuel pump priming when it is cold. But if the car has been running for any amount of time and I turn off the car my fuel pump does not want to prime. Is this a sigh that my fuel pump is going bad? I have heard that fuel pumps will go bad when they heat up....Thanks Chris
 
Fuel pumps fail in several ways and many go intermittant before total shut down. Fortunately, your fuel pump is not in the gas tank so it is easily changed for another. I would change it now and not let it strand you. I would also change out the gas filter which is in the vicinity of your pump.
 
Fish;

You haven't said if the car starts when warm.

Another thought...measure the voltage at the wire connections at the pump when both cold and warm. Before replacing the pump, make sure that you don't have a less expensive problem with the main or fuel pump relays first.

If the car starts when warm, putting a fuel pressure guage in line at the filter with a tee and measuring fuel pressure when the pump primes when cold and comparing that to when the engine is warm might also shed some light on what is happening.

Good luck!
 
Michael has a good suggestion. The fuel pump, if it is healthy should draw about 75 or 80 psi under static conditions. That is when the gage is directly connected to the fuel line and blocks it. The pump when teed in as Michael suggests should show about 40 psi when regulated at the fuel rail. The regulated pressure should be fairly constant but vary 5 psi with manifold pressure changes.
 
what do you mean by you hear it ''priming''it should not have to prime once installed.I havent heard my pump do any thing since i started driving a fuel inj model my old 72 had carbs and the system lost pressure when parked and the pump would run till it got pressure back up. I have never heard a jag pump prime after once pressured up.
 
WEll I replaced my fuel pump and everything seems to be working fine now. Thanks everyone for their input.....Chris
 
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