My son just purchased a 1992 F150. It has 100000 km on it. It started beautifully and the fast idle shut down after a couple of minutes as it should. He drove it home (about 6miles) and it was now idling very fast. He turned the engine off while it was idling fast. He called to make an appointment for a safety check and went out a few minutes later and it would turn over but not start. We thought it might be flooded so tried starting a few times with the accelerator to the floor. We added about 2 gallons of gas to the tank just in case it was short. We let the truck sit for several hours before trying again. There is lots of fuel in the rail and we have spark. The sparkplug we removed is dry. The truck hasn't been driven much for about 10 months. We tried switching to the back fuel tank with no change.

Any ideas.

 

Take a long screwdriver (or something) and listen to the injectors, put one end on an injector and the other end next to your ear. Try starting the truck and see if you hear CLICK CLICK CLICK CLICK.

All injectors, without exception, are essentially "noisy little devils". When they are working correctly, they click away like mad. When they aren't working correctly, then they don't click away like mad.

Sound like all of the injectors are not firing, let us know.

 

We haven't tried to test the injectors yet. We decided to try replacing the fuel filter first. We think that by switching to the back tank (which we suspect hasn't been used for a long time) we might have drawn some sludge into the filter which prevents us from getting enough fuel pressure to the engine (we haven't checked fuel pressure as we don't have access to a guage). Anyway we felt a new filter is good routine maintenance and easy to do.

Not so. We have removed the clips from the filter and have the special tool which slides up inside the hose adapter. But we can't get the clips to release. Are there any special techniques? I think the fuel flter might be the original installed in 1992

 

You can use one of those dial tire gauges that O'Reilly sells. On a cold, not running engine there is not much danger of fire with it. Just hold it on the schrader valve on the fuel rail while cranking. It also works for checking your A/C system.

 

You can spray WD-40 or PB Blaster into it and let it set for a while, then push the tool into it and under the Garter Spring, twist until the "O" rings let go, and then pull apart.

Fuel Filter, In-Line

CAUTION:
If the fuel filter (9155) is being serviced with the rear of the vehicle higher than the front, or if the fuel tank (9002) is pressurized, fuel leakage or siphoning from the tank fuel lines could occur. To prevent this condition, maintain the vehicle front end at or above the level of the rear of vehicle. Also, relieve fuel tank pressure by loosening the fuel fill fuel tank filler cap (9030). Fuel tank filler cap should be retightened after pressure is relieved. Depressurize the fuel line system at the Schrader valve on the engine fuel rail. If vehicle is warm, change the fuel filter before the pressure rebuilds.


Removal

1. Shut engine (6007) off. Depressurize fuel system. Refer to Service Procedures, «Fuel System Pressure Relief» in this section.

2. NOTE: When the battery is disconnected and reconnected, some abnormal drive symptoms may occur while the powertrain control module (PCM) (12A650) relearns its adaptive strategy. The vehicle may need to be driven 10 miles or more to relearn the strategy.

Disconnect battery ground cable (14301).

3. Raise vehicle on hoist. Refer to «Section 00-02».

4. Remove filter-to-fuel line retainer clips.

5. Remove push connector fittings at both ends of the fuel filter as described in Removal and Installation, Push Connect Fittings in this section.

6. Remove two nuts from filter studs and remove fuel filter bracket (9A335).


Installation

1. NOTE: Note that the direction of the flow arrow points to the tab of the fuel filter bracket against which the fuel filter rests.

Install fuel filter assembly and two nuts. Tighten nuts to 8-10 N-m (6-7 lb-ft).

2. Install push-connect fittings onto fuel filter ends as described in Removal and Installation, Push Connect Fittings in this section.

3. Snap on filter-to-fuel line retainer clips. Long legs of clips go onto fuel lines.

4. Lower vehicle and connect battery ground cable.

5. Turn ignition switch (11572) from OFF to RUN position several times without starting engine. Check for fuel leaks.

 

I wish we had this truck on a hoist. Unfortunately it is parked on the street in font of our house. So, it is a matter of lying on the street under the truck to work on it.

 

I have tried a tire gauge on the schrader valve, but it doesn't go on far enough to release the valve.

 

The one I got there will do it, look at different ones before you buy a gauge and make sure the release part sticks out far enough before you buy one.

 

Having been unable to replace the fuel filter, and not being able to testthe fuel pressure, we decided to to test the injectors with a long screwdriver. To our surprise, the engine sputtered briefly. We attached a power pack to the battery for a little extra power and tried starting with no success. We then srayed a little ether into the throttle bady and it started and kept running. We drove the truck for about 10 minutes and by that time it was on the extremely fast idle again.
We turned it off and again it would not restart.
So it would now seem that the problem is connected to the warm engine and the fast idle.

 

Sounds like a bad MAP sensor or the hose has come off of it.

 

The fuel system has a fault.
By spraying ether in and having it start shows the ignition is ok.
Running high idle shows it is very lean or has an air leak into the intake system.
You have to check these things out instead of dacing around them if the truck is to ever run useful.

 

If you know how to check for codes, see if there is a code 53. I suspect the TPS is shorted to power, telling the ECM to go into clear flood mode during cranking. This is why you have spark but no injector pulse. This could also explain the high idle.