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Re: fuel pump continued part 2 Posted by Cmyles [Email] In Reply to: fuel pump continued part 2, sarah, Wed, 7 Apr 2010 18:00:08 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Sarah,
It think your engine is flooding out. It runs when you hold the accelerator pedal down because that allows maximum intake of air which makes a somewhat burnable mixture with the massive amount of raw gas in the induction system. Two things are likely to be causing this; 1)jammed fuel injectors or 2)defective fuel pressure regulator. An injector is a small needle valve that opens and closes rapidly allowing gasoline, under pump pressure, to squirt into the induction system. A tiny speck of dirt can jam an injector so that it fails to close and gasoline squirts unrestricted into the manifold. Tell-tale signs (besides poor performance) include raw gas in the cylinders after the engine is shut off. Turning the engine off normally stops the fuel injection instantly but with a jammed injector fuel will keep pouring into the cylinder until the system pressure is bled off. You can also pull the injectors out and see if they leak by running the pump (put the key in "Run" for a few seconds) and pressurizing the system (be careful, gas may spray). If you don't crank the engine the injectors should remain closed.
If your fuel pressure regulator has a perforated diaphragm it will allow raw gas to be drawn by engine vacuum through the vacuum hose into the manifold causing a rich mixture. Run the engine for a minute and then (shut it down and) pull the FPR vacuum hose off the manifold and check for evidence of gasoline in that hose.
Jammed fuel injectors are the more likely suspect given the extreme problem you're having.
posted by 198.233....
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