Confirm a diagnosis: FPR &/or injectors

[kstrading]

1992 Ex symptoms: Cold start ok but idles high. Rough re-start 10 min. after warm. Idle won't settle in, runs high and usually stays up around 1500.
What I've checked/replaced:
Motorcraft plugs & wires
Propane test for vacuum leaks.
Swapped coil packs, swapped ignition control modules.
New Motorcraft fuel pump last year.
Sensors: new MAF, ECT, ACT, TPS, IAC, CPS
Computer resets after changes.
Did leak down test on fuel pressure: key on: 36 psi, running: 28 psi.
leaked down to 20 psi in 30 minutes.
Codes: koeo: 111 (pass) koer: 411
Injectors? FPR? Need your advice. Thanks.

 

[410Fortune]

I would start by checking for manifold vacuum leaks. Doesnt seem like a fuel related problem to me.

Whatever you do stop replacing parts, your list of sensors there is up in the range of $500 or so already spent....

high idle = check manifold vacuum.

 

[kstrading]

Thanks 410.
I'm gonna pull the upper intake and check the lower. Probably re-gasket and torque.
I'll look over the fuel rail & injectors while I have it apart.

 

[410Fortune]

Or you could get a cheap vacuum tester?? The early 4.0L OHC can use a good upper end re-seal for sure so its up to you.

Vavle covers, lower intake, upper intake and fuel injector hats and O rings can never hurt. But a vacuum test can quickly tell you if there is a problem. You might spend another $150 or gaskets, O rings, etc and then still have the issue.

 

[Diddy74]

What would be a good example of a cheap vacum tester,(brand) where could I get one?

 

[410Fortune]

Checker, Autozone, etc.
Not sure of the brand, but they all stock them. Most of them double as a fluid pump/bleeder as well. Very handy tool to ahve around.

 

[Diddy74]

Ok cool i'll check them out..ugg autozone....nuff said

 

[kstrading]

Update on the idle problem: I pulled the upper intake, re-torqued the lower and checked injectors. There was no vacuum leak. Ended up finding that the throttle body was worn around the butterfly, allowing too much intake air passed it. I adjusted the stop screw and the tps to solve the problem.... eventually I'll be needing a new throttle body. Thanks for your responses.

 

[Glacier991]

Often high idle problems point to a TPS issue....always worthy of a check.