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Marc, Technician
Category: Car
Satisfied Customers: 1888
Experience:  33 years exp. automotive repair NYS emisisions repair cert.
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I have a 1990 motorhome E-350 ford 460 fuel injected. In ...

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I have a 1990 motorhome E-350 ford 460 fuel injected. In the middle of a trip it began run rich, it would stall at idle. it would run at high speed but produce black smoke. Now if it starts in runs ruff and stalls. Thinking a fuel injector problem, but it's not just one all the spark plugs fouled. I also have some gas in the oil. Thinking one or more of the senesors rather than pulling all the injectors????

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1990 Ford E-350 460

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You need to check the fuel pressure regulator .

Those are classic symptoms of a bad fuel pressure regulator.

Pull the vacuum line off the regulator after it has just been running if the inside of the hose is wet change the regulator.

Check to make sure the regulators diaphragm holds vacuum.

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Customer: replied 11 years ago.
Relist: I still need help.
Checked the fuel pressure regulator, it holds vacumn. check engine light never came on (thuoght that might help) Any other ideas???
Are you saying that the check engine light does not even come on when you start the engine??
Customer: replied 11 years ago.
Reply to Marc's Post: The engine light comes on when started but does notstay on so I figure it won't show any defect codes????? Thanks
It may be a sticking fuel pressure regulator or a restricted return line. (just thought about it) You need to run a fuel pressure test as described below.
All EFI and SEFI equipped vehicles should be 30-35 PSI at idle and 40-45 PSI with the vacuum line removed from the regulator. Disconnect the return line at the engine fuel rail and run a hose from the return fitting on the rail into a gas can. If the pressure is still high, replace the regulator. If not, check the return line for a restriction. Clean or replace the return line as necessary.
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