1999 Ford F150 - Fuel Pressure Test

[MAS1866]

Does anyone know precisely where the fuel pressure test port is on a 1999 Ford F150 4.6L is?

[Tim Martin]

If I am not mistaken there is a fuel pressure rail running from front to back on both sides of the engine and around the back of the engine. Basically the rail surrounds the intake manifold. The service port I think is on the drivers side fuel rail roughly about 1/2 way back pointing upwards.

hth.

[steven kiser]

as a rule about 1/2 way down the drivers side rail. it may be covered with a wiring or vac line harness. there are two 4.6's for this year, maybe one is different from the other. i've never run into an issue with fords. on occasion i'll split the line at the filter and install an adapter. i will warn you though, if the cap is missing (i see this a lot) clean port thoroughly before you tap into it. if it isn't clean then you may end up with a leaker and it may break when you try to remove it.

[Tim Martin]

btw. Fuel pressure specs are: KOEO 30-45psi and KOER 28-45psi. Good luck.

[MAS1866]

So o.k. I've got this truck in the shop. I found the pressure check port(thank you). Fuel pressure is arund 35 psi. There no codes, but it still won't run.
The truck starts fine, but when I let go of the key, it dies.

[steven kiser]

put an ignition module in it.........

[brianp87]

Does it lose spark?

[Tim Martin]

The truck starts fine, but when I let go of the key, it dies.

Ok. Does the engine shut off because the ignition switch is released from the start position or is that all the longer it runs even if the switch was in the start position?

Could be steve's hunch of an ignition module is on target but I've seen an ignition switch and a camshaft sensor do the same thing. So if that truck was here in my shop, I'd be hooking up the lab scope and doing more diagnostics before installing parts.

hth

[brianp87]

Exactly dont assume anything. I didnt see the ignition part if it quits after letting it go I would look there

[steven kiser]

didn't mean to sound like a parts thrower. i've just done so many of them it just popped out. could be a bad ig switch or broken run wire to module.

[brianp87]

didn't mean to sound like a parts thrower. i've just done so many of them it just popped out. could be a bad ig switch or broken run wire to module.

I agree with you but for someone to learn they need to know what to test and why.

[Tim Martin]

That's one of the value of a forum like this. We can share and learn from each other.

Thanks to each one for their part.