XJ No fuel

BB98xj

BB98xj

Well-Known Member
Joined
May 4, 2010
Location
King
first crank after sitting for over 30 minutes is *usually* a long crank, then it fires right up. I let it sit and checked for fuel at the Schrader valve on the rail and no fuel.

Fuel pump?
 
Could be check valve or the early warning your fuel pump is about to take a dump. Same symptoms for me and it turned out to be the pump. It wasn’t keeping the lines pressurized and led to long starts until it primed. At least it’s giving you a warning. Had a fuel pump instantly quit on me on my boat in the middle of the lake with no warning by myself. That was a good time.
 
Wes said:
Could be check valve or the early warning your fuel pump is about to take a dump. Same symptoms for me and it turned out to be the pump. It wasn’t keeping the lines pressurized and led to long starts until it primed. At least it’s giving you a warning. Had a fuel pump instantly quit on me on my boat in the middle of the lake with no warning by myself. That was a good time.
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Hopefully you had a paddle with you!

Are you guys talking about the check valve at the pump? Or the regulator at the rail?
 
Yeah there is a check valve integrated into the pump. You can check whether it's pressure regulator, injectors, or pump by blocking off the pressure line with a gauge. Watch pressure. If it holds on the supply line, pump & check valve are ok. If you block off the return line, you can check injectors after checking the pump. If that holds, then it must be the pressure regulator bleeding pressure. Rule of thumb is half the specified pressure in thirty minutes (39 psi for return systems, 49 returnless) . If it's returnless, the regulator is part of the sending unit and if it leaks down with the gauge at the pressure feed, replace the whole fuel pump unit, and it'll fix it. If that tests out ok, and then pressurize the system and it leaks down, pull the fuel rail, and I'll garuntee you've got a leaky injector. Which will eventually lead to a failed converter.
 
a_kelley said:
Yeah there is a check valve integrated into the pump. You can check whether it's pressure regulator, injectors, or pump by blocking off the pressure line with a gauge. Watch pressure. If it holds on the supply line, pump & check valve are ok. If you block off the return line, you can check injectors after checking the pump. If that holds, then it must be the pressure regulator bleeding pressure. Rule of thumb is half the specified pressure in thirty minutes (39 psi for return systems, 49 returnless) . If it's returnless, the regulator is part of the sending unit and if it leaks down with the gauge at the pressure feed, replace the whole fuel pump unit, and it'll fix it. If that tests out ok, and then pressurize the system and it leaks down, pull the fuel rail, and I'll garuntee you've got a leaky injector. Which will eventually lead to a failed converter.
Click to expand...

Thanks for the help! I tried it this AM before I left for work and it fired right up. Its intermittent and a PITA.
 
Sounds electrical. I'd check the fuel pump ground. It's in the rear driver side cargo area IIRC. Could also be the fuel pump relay. Best way to stop long cranks is to prime it three times.
 
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