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low fuel pressure w/ ignition on

Old 01-31-2010, 03:45 PM
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Default low fuel pressure w/ ignition on

My 98 SS has been having trouble getting started lately, the car will crank about 5 seconds before it barely fires up. i had a mechanic hook a fuel pressure gauge and with ignition on it barely gets 10 psi, but once it fires jumps up to about 55 psi. the fuel pump is fairly new and i just changed a fuel pump relay that didnt help. what about the regulator??? thanks for any help
Old 02-17-2010, 10:41 PM
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weird timing. my 98 ss is doing the same exact thing you are describing. when its cold it takes about 3-5 seconds to crank and fire. i thought it was a bad battery, changed it and still does it. when the car is warm and you go to crank it over it fires instantly. im thinking my fuel pressure is low as well, and the previous owner said the fuel pump was replaced.
Old 02-18-2010, 07:45 AM
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Question Could be???

Small leak at the pump? Since the PCM only cycles the pump at key on, for a couple secs, the leak disallows psi build??
Once PCM sees enuf rpm, the pump stays on, overcoming the leak.
[Common thread: Both cars have had the pump replaced.]
Old 02-23-2010, 04:07 PM
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My guess is a bad fuel pressure regulator.


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