99 f150 interment no start hot

rayhubble · May 28, 2009

4.6 eng no codes, 40 lbs of fuel psi any tips on where to start?

Bruce Amacker · May 28, 2009

I'd check fuel flow on the return side. It's a return system, right? A weak pump will cause this due to fuel boiling in the rail and not enough ooomph from the pump to flush the vapors out. I had my ass beat by one like this a few years ago and it taught me a lot about fuel flow. Return flow should be like a hard piss- more than a pint in 30 seconds. 40psi doesn't mean anything if the flow is low. Don't measure flow on the supply side, measure it on the return side after it overcomes the regulator.

Good Luck!

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Brad Clayton · May 28, 2009

I would do a real good visual on the engine compartment to start with, looking for anything out of the ordinary, rust, chaffing, add ons, ect. I would also check the connection at the crank sensor, a known problem with these. If in doubt replace the pins in the connector.

GregKneupper · May 28, 2009

When the problem occurs does the theft light flash and is the odometer dashed out? I have been seeing alot of eec relays sticking lately.

Mekanik · May 29, 2009

4.6 eng no codes, 40 lbs of fuel psi any tips on where to start?

You are sure that you have 40psi of fuel pressure when the problem occurs?

Inspect the wiring at the a/c accumilator. I have seen chaffing there before.

rayhubble · June 3, 2009

hey guys thanx for the tips finnaly got it to act up after driving it 200 miles fuel psi droped to 10 psi and then it would not start again, i ended up replacing both the pump and regulator.