Fuel Drain Back

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Mar 11, 2007 | 10:49 PM

Jailhouse Jim

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Fuel Drain Back

I have a 2001 Ford F-250 that acts like the fuel prime is syphoning off overnight. It may take 1 day or five but when you go to start it, it stumbles and acts as if there is air in the system. It will clear itself after a minute or two of idling or clears quickly if you bring the engine rpm up. Could the fuel be draining off creating an air issue? Is there a check valve to stop this? When I purchased the vehicle the fella said he replaced the fuel pump and I have changed the water drain and filter due to leakage. This issue has not gotten any better. When it starts there is no smoke as would be indicitve of glow plugs and you can hear the air going through as the enging will stumble. What do you all think? After the intial start, the pickup runs good all day long with no issues.

Jailhouse Jim

Mar 12, 2007 | 07:58 AM

Pocket

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From: Parker, CO

It is normal for fuel pressure to bleed off after you stop the engine. The fuel bowl stays full, but if you install a pressure gauge, you can watch the pressure drop with the engine off. The fuel pump kicks on and runs for 20 seconds with the key in the run position to prime the fuel system. All our PSD's do this and it's perfectly normal. Takes only about 5 seconds or less to pressurize the fuel system to be able to start, about the same amount of time it takes for the glow plug lamp to shut off on a cool morning.

More than likely it's not a fuel issue, but rather an oil pressure issue. A leakback in the HPOP system can cause hard start issues, and even stumbling for a minute after the truck has started. Check the oil level in the reservoir by popping the small cap off the top of the HPOP. The oil should be within a half inch from the top. Check it after your truck has sat for a day or so.

Mar 12, 2007 | 07:49 PM

Jailhouse Jim

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Start up stumble

Quote:

Originally Posted by Pocket

So if this is the case, what is the cure? This fuel system is totally foreign to me. I am used to the old direct injection from a Roosa Master or piston style pumps. This high pressure oil deal is interesting and confusing at the same time.

Jailhouse Jim

Mar 12, 2007 | 07:55 PM

Kwikkordead

Fleet Owner

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From: Rio Rico, AZ.

There's a check valve that is installed in the bottom of the HPOP reservoir that is supposed to prevent drain back.
I have no personal experience to offer you, but I have heard plenty of testimony that it needed to be fixed.

Mar 12, 2007 | 07:56 PM

Kwikkordead

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From: Rio Rico, AZ.

Another thing that comes to mind is >sometimes< the main oil pump mounted on the crankshaft gets tired and has to be replaced as well.

Mar 13, 2007 | 05:59 PM

Jailhouse Jim

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My oil pressure is good. The level in the HPOP is at least an inch below the top of the resevoir so that may be it. Any ideas how to make the repair?

Jim

Mar 13, 2007 | 06:26 PM

clintbonnie

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From: Ardenvoir, Washington

I would suggest switching to Shell 5w40 synthetic. The dino oil will cause running problems on start up. The injectors need a good supply of oil and will cause the engine run bad until the suppy feeds all the injectors.. My 99 on start up, even with new oil in it, would romp, romp until I changed to synthetic.. It is more money but good insurance..I would never go back to dino..Have you check for any fault codes?