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hello thanks for using just answer
It sounds like you may have a defective fuel pressure regulator. this is located on the fuel rail. Make sure the vacuum hose going to it has vacuum and is not kinked or broken.
Hi - That would be nice, but I think that the regulator refers to GEMS engines (up to '99). Ours is a Bosch engine - according to RAVE:
There are eight fuel injectors, one per cylinder which the ECM operates sequentially. All the injectors are fed from a common fuel rail as part of the returnless fuel system. Fuel pressure is maintained at a constant 3.5 bar (52 lbf.in2) by a regulator that is integral with the fuel pump.
Am I wrong?
I am not in a hurry, so I will check it out and get back to you in the morning.
I have searched with inspection mirror & light. Also, I have been reviewing the workshop manual. For the pre-99 4.0 the pressure regulator is obvious in the diagrams, and addressed in the repair guide (page 416) - just as you describe. But post-99 diagrams do not show a regulator on the fuel rail, nor do the fuel rail refit instructions mention it. The only reference to a regulator is in the tank, which was just replaced.
Any other thoughts?
I know this is not an easy fix and I appreciate your patience.
I attached a fuel pressure guage to the fuel rail - when the car runs, it reads @ 51psi - normal. When it stalls, it's reading @ 48psi. I can try to start the car and after several tries - it may start. Pressure is back to 52 untill it stalls.
I just tried starting it again. Here was the sequence. Pressure was low (20psi). Released pressure to 0. Turned on ignition. Pressure 0. Started car - pressure jumped to 51psi. Car ran for @ 10 minutes till it warmed up. Car stalled. Pressure reads 48psi. Can't restart. I am beginning to wonder if there's a temperature relationship -???
And you were having this problem before replacing the pump? I would hook a voltmeter into the fuel pump wires and see what the voltage is doing when pressure starts dropping. if voltage is dropping with pressure then we know we have some high resistance in the wiring.
Do me a favor. clean your battery cables good. make sure there is no corrosion at all. i remember working on a land rover doing some crazy stuff and had a dirty battery terminal. worth a try
I will give it a shot and get back to you - I agree - you never know....
I have cleaned both battery terminals and repeated the test again, the engine starts right away when cold and runs fine. It stops as soon as it warms up and cannot be restarted.
it is possible the fuel cutoff switch is getting hot and dropping voltage. this should be down on the right hand kick panel. check the connector and see if corroded or melted looking. the power runs thru this for the fuel pump. if looks ok we need to see voltage going into and out of switch when acts up
There had been a fault code relating to a weak signal some time ago. But the check engine light is off now and has been for some time. I am assuming that there are no new codes.
As far as alarm - I had trouble with the front driver side door causing the locks to jump up and down repeatedly -- I was afraid that the circuits would burn out. Also, when there was an alarm issue, the starter was completely disabled.
The car starts when cold and runs smoothly, no misfires (plugs and wires replaced over the summer), but it stops when it warms up. It won't restart until it cools down. Low fuel pressure appeared to have been a problem, but I replacd the pump. Perhaps it was a symptom or a cause of the alarm issue.
I fear this is a quirk with the P38s - I welcome a solution.
I will do as you suggest - looks like a challenge to get a wrench around it. Before I order, the temperature guage seems to be working fine. Wouldn;t that eliminate the engine coolant temperature sensor as a potential cause?
I have ordered the part. I am going to accept this answer as well, though I am sure I will have additional questions. I feel bad that the original mechanic was unable to resolve the issue - I wish there could ba a way to pay partially.
But I believe this is the right direction.
Thanks for your response.
I hope you are having a good holiday. I replaced the ECT sensor (Land Rover part) and see the same result. The car stalls as soon as it warms up.
What would be the next step.
Just checking in - I assume you are on holiday, but I would like to follow up as soon as you are back. please see my last post - the car still shuts off as soon as it warms up.