Hello all. I've got a '92 Ford F150 Supercab with a 351 Fuel Injected Windsor engine. This morning the truck my father had trouble getting it to fire up. It would just crank and not turn over. So on the third attempt, my father stepped on the gas pedal and the truck started and revved the heck out of it and noticed blue blackish smoke from the tail pipe. Anyhow, the weather this morning(Thurdsay morning)was foggy and wet here in Southern California. Do you think that the moisture would have been the culprit for the hard starting? Normally it starts up right away. Oh, also is it normal for these Ford Trucks to take four seconds to start? I am used to other vehicles starting up at the tap of the starter. Is it possible to make this truck to start at the tap of the starter-within a one second time limit? The starter has been replaced and a complete tune has been performed about a year ago.

 

bump to top. See if someone might help.

 

There are a couple of things that could cause this - but can you clarify:
Does the truck crank (engine turning, but not running on it's own) without running for four seconds, or:
Not crank (no engine turning, no starting) for four seconds...

To "crank" and "turn over" both describe the starter turning the engine before the engine begins to run on it's own. I have several suggestions depending on the nature of the problem. Let me know,
Chris

 

I'll jump the gun -- I think you mean the stater cranks the engine fine, but the engine will not start.

The PCM has a "clear flood" mode. If you floor the throttle during crank, it will cut off fuel flow to the injectors. It sounds like this is how your father got it to start --
the blue/black smoke afterwards is consistent with a flooded engine.

My truck starts in about 1 second of cranking, maybe less.

From this set of symptoms, I would guess you have a failed fuel pressure regulator or a leaking fuel injector. Either situation will cause raw gas to be dumped into the engine, flooding one or more cyclinders. It will also de-pressurize the fuel rail, starving the engine for fuel on the next start attempt. You will either experience a flooded condition (if you try to restart right away), or a long crank time (if you try to start more than (say) 30 minutes later).

Pull the vacuum line off the regulator. If it has fuel in it, the regulator is bad.
If this test passes, connect a fuel pressure guage to the regulator. Observe the correct PSI with the key on, engine off. Turn the key off. Observe that the pressure does not bleed down more than 5 PSI in 30 seconds. Now start the engine. Observe that pressure drops by about 5 PSI at idle, relative to engine off.

If any of these tests are not met, you have a fuel delivery or leakage problem. If the fuel system looks OK, it is possible you have a failing TFI module, bad secondary wiring in the ignition system, or a problem with the distributor cap, rotor, etc.

 

My brother in law has a 92' 5.0 with the same problem. Can you help us find the fuel pressure regulator and I'll try the vacum line test first.

Thanks

hovey30

 

Fuel pressure regulator sits on the fuel rail and is a small round diaphragm holding device. If it is pinholed or the vacuum line is leaking it will give you a variety of responses from full rich to undependable variables. Test the fuel pressure at the schraeder valve (looks like tire stem) on fuel rail with tester on loan from parts store in your area. Advise fuel pressure.
Tex

 

Step on the front bumper and look all the way at the back of the engine next to the firewall. You will see a bracket with three solenoids on it (TAD, TAB, and the EVR). You can recognize these controls because they get both electric wires and vacuum hoses. The fuel pressure regulator is right next to this bracket, towards the centerline of the engine. It's the 2 inch diameter round "thingy" that has a vacuum hose connected but does NOT have wires going to it. You should also see the fuel pressure line coming in and the fuel pressure return going out.