Losing prime after shut off?
03-04-2017, 05:05 PM
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Losing prime after shut off?
OK I got a 2002 24v I bleed it it starts runs fine revs up fine for like 30min or more no problem but if I shut it off it loses prime no and no fuel in filter the one after electric pump on side engine ? Primed again runs suit off won't start same thing ? Help! !!
03-05-2017, 04:00 AM
#2
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Check the lift pump right now!
To me it sounds like you have two problems:
A- No lift pump pressure, the injection pump sucking through a dead LP and the filter.
B- A leak that makes you lose prime.
I would take a good look at the fuel lines and hoses, (replacement kit can be odered at fostertruck.com or built yourself with off the shelf materials) and at the quick connect fittings on top of the tank. Those sometimes rust away.
To me it sounds like you have two problems:
A- No lift pump pressure, the injection pump sucking through a dead LP and the filter.
B- A leak that makes you lose prime.
I would take a good look at the fuel lines and hoses, (replacement kit can be odered at fostertruck.com or built yourself with off the shelf materials) and at the quick connect fittings on top of the tank. Those sometimes rust away.
03-05-2017, 09:39 AM
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A common problem is a leak in the return line, usually at the back of the head where it is hard to detect. Because it is not under pressure, fuel staining is almost nil making it hard to see. On my truck, I opted as a precautionary measure to place a one way check valve between the lift pump and the tank. No more drain back.
03-07-2017, 06:41 PM
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No lp pressure then how does it start?and run
Check the lift pump right now!
To me it sounds like you have two problems:
A- No lift pump pressure, the injection pump sucking through a dead LP and the filter.
B- A leak that makes you lose prime.
I would take a good look at the fuel lines and hoses, (replacement kit can be odered at fostertruck.com or built yourself with off the shelf materials) and at the quick connect fittings on top of the tank. Those sometimes rust away.
To me it sounds like you have two problems:
A- No lift pump pressure, the injection pump sucking through a dead LP and the filter.
B- A leak that makes you lose prime.
I would take a good look at the fuel lines and hoses, (replacement kit can be odered at fostertruck.com or built yourself with off the shelf materials) and at the quick connect fittings on top of the tank. Those sometimes rust away.
no lp pressure then how does it run?
03-07-2017, 08:52 PM
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03-07-2017, 09:18 PM
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It sounds to me like you have a slow air leak on the suction side of the system. When you bleed the system and prime it, the fuel flow is faster than the air leak, so it will prime and run.
Then you start it. The engine runs fun while an air bubble builds larger and larger until the lift pump loses prime.
Check your fuel supply plumbing from the lift pump back to the tank. Disconnect the fittings, pressurize gently with air and check for leaks by listening or with soapy water.
The giveaway is the empty filter canister. If the supply side is airtight, you'd have a filter can full of fuel and the VP would suck fuel all the way from the tank. Lots of trucks driving around on totally dead lift pumps because once running, they often stay running.
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03-15-2017, 09:20 PM
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it was fuel pump replaced it and wala
The fuel system is normally closed. For fuel to leak out (and the engine to lose prime) there must be a path for air to leak in. Otherwise, it's like inverting a full glass in a sink full of water and lifting up, but not above the water level. The water will stay in the cup until there is a path for air to enter and let the water displace to the sink.
It sounds to me like you have a slow air leak on the suction side of the system. When you bleed the system and prime it, the fuel flow is faster than the air leak, so it will prime and run.
Then you start it. The engine runs fun while an air bubble builds larger and larger until the lift pump loses prime.
Check your fuel supply plumbing from the lift pump back to the tank. Disconnect the fittings, pressurize gently with air and check for leaks by listening or with soapy water.
The giveaway is the empty filter canister. If the supply side is airtight, you'd have a filter can full of fuel and the VP would suck fuel all the way from the tank. Lots of trucks driving around on totally dead lift pumps because once running, they often stay running.
It sounds to me like you have a slow air leak on the suction side of the system. When you bleed the system and prime it, the fuel flow is faster than the air leak, so it will prime and run.
Then you start it. The engine runs fun while an air bubble builds larger and larger until the lift pump loses prime.
Check your fuel supply plumbing from the lift pump back to the tank. Disconnect the fittings, pressurize gently with air and check for leaks by listening or with soapy water.
The giveaway is the empty filter canister. If the supply side is airtight, you'd have a filter can full of fuel and the VP would suck fuel all the way from the tank. Lots of trucks driving around on totally dead lift pumps because once running, they often stay running.
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