94 Ford 150 Won't start

I'm lost, the truck was running fine, started right up and I let it run to warm on a cold morning and it died will I was inside. Now it won't start period. It cranks, dash lights work, I hear a Click when I turn the ignition to on (assume thats the fuel Pump priming), switched tanks back and forth, the fuel guage changes as the its switched (again I;m assuming the switch works) Sprayed starter Fluid in the Throtle Body and she wanted to start but never really fired, checked for spark at the plugs, Got a Spark...The Fuel pump inertia switch is still in the down positon never popped up..so that looked good

...All in all I'm lost and need HELP......Got a New fuel pump relay but I cant find were it is mounted on the truck....

I'm lost, the truck was running fine, started right up and I let it run to warm on a cold morning and it died will I was inside. Now it won't start period. It cranks, dash lights work, I hear a Click when I turn the ignition to on (assume thats the fuel Pump priming), switched tanks back and forth, the fuel guage changes as the its switched (again I;m assuming the switch works) Sprayed starter Fluid in the Throtle Body and she wanted to start but never really fired, checked for spark at the plugs, Got a Spark...The Fuel pump inertia switch is still in the down positon never popped up..so that looked good

...All in all I'm lost and need HELP......Got a New fuel pump relay but I cant find were it is mounted on the truck....
Check to see if you have power to the inertia switch. Hook a test light up and turn the key on. You should have power at one of the wires for a few seconds(grn/yel ) i think. (Youll have to repeat this for testing, cause the pcm shuts off the power to the pumps if the engine doesnt start) If you do , the relay is ok, its mounted in the power distribution center, under the hood. Power goes from it to the inertia switch, and from there to the fuel pumps. If you have power going to the inertia switch, but not coming out, the switch is bad. The contacts oxidize in them sometimes. If you have power coming out to the pump, its probably bad, or bad wiring in between. You can also put a jumper wire on the inertia switch harness and see if it starts. If it does, dont be tempted to leave the jumper there for long. Its there to shut off the pumps in case of a crash, to reduce the risk of fire. Good luck
Later
Ed
.

OK thanks for the Reply. This is were I am currently..On the Inertia switch I have power going to from the Green/Yellow wire. I popped the interia switch Open and then back closed...Then I Probed the red/Yellow wire comming out of the Interia switch and had Power.. So I if read your reply correctly that should lead me to the Fuel Pump.

Question: with Dual Pumps I cant see both of them being bad.
Is there a external pump between them? If so were?

I was looking at the Haynes Manual and It talked about the MAP sensor controls the Fuel and Air by use of the PCM any help there..:)

OK thanks for the Reply. This is were I am currently..On the Inertia switch I have power going to from the Green/Yellow wire. I popped the interia switch Open and then back closed...Then I Probed the red/Yellow wire comming out of the Interia switch and had Power.. So I if read your reply correctly that should lead me to the Fuel Pump.

Question: with Dual Pumps I cant see both of them being bad.
Is there a external pump between them? If so were?

I was looking at the Haynes Manual and It talked about the MAP sensor controls the Fuel and Air by use of the PCM any help there..:)
Ok, sorry i didnt notice you said you had dual tanks. Power goes from the inertia switch, to the tank selector switch, then to the pumps. You are right, the odds of both pumps going bad are pretty slim. You can check power at the switch, or at the harness connector on the tanks. You can hook jumper wires to the tank harness` to see if the pumps run , just disconnect the harness to prevent any backfeed. Some of the older model trucks did have an external high pressure pump , frame mounted, under the drivers seat. Yours doesnt, i think they quit using that in 90, or 91. You asked about the map sensor. It does help control the air fuel mixture, but it sends signals to the computer , and the computer controls the fuel/air mixture, along with input from other sensors. It doesnt control the pumps though , and normally wouldnt keep one from starting.
Later
Ed
.

Well the best thing I found out is to KEEP a apostiive attitude. This truck is drviving me nuts...found fuel is getting to the Fuel rails at the injectors. The Shrader valve, when I depressed it. the fuel just rolled out of it. Instead of squirting like it was under pressure...Could it be that I am not getting Fuel pressure,,,if so were would I begin to look....thanks for all the help but this truck is dead in the water right now:)

Well the best thing I found out is to KEEP a apostiive attitude. This truck is drviving me nuts...found fuel is getting to the Fuel rails at the injectors. The Shrader valve, when I depressed it. the fuel just rolled out of it. Instead of squirting like it was under pressure...Could it be that I am not getting Fuel pressure,,,if so were would I begin to look....thanks for all the help but this truck is dead in the water right now:)
With the tests youve done, have you determined whether the pumps are running or not? You should be able to hear the pumps for a few seconds, after you turn the key on. This will be a whirring sound, not a clicking sound. You can take a piece of hose, and stick it in the filler neck, and hold it to your ear when you turn the key. If the pumps are coming on, you should have pressure at the schrader valve.(more than a dribble) If you dont have a pressure gauge to test with, take out the valve, and hook a piece of fuel line to the fitting long enough to reach a container. Turn the key to power up the pumps, and you should get a strong , full stream of fuel(25-30 psi if you have a gauge) If the pumps are running , and you have no , or little pressure, the filter could be clogged, or the pressure regulator bad. But the symptoms you described dont indicate either. Good luck
Later
Ed
.

Well, since it won't start with either tank, I'll ask you this: When was the last time you replaced the fuel filter? It could be plugged and both tanks funnel into the only filter on it. Will it start if you press on the gas pedal? If it does, it may be a sticking IAC (idle air control) valve which is located around the throttle body. try this and see what happens.

With the tests youve done, have you determined whether the pumps are running or not? You should be able to hear the pumps for a few seconds, after you turn the key on. This will be a whirring sound, not a clicking sound. You can take a piece of hose, and stick it in the filler neck, and hold it to your ear when you turn the key. If the pumps are coming on, you should have pressure at the schrader valve.(more than a dribble) If you dont have a pressure gauge to test with, take out the valve, and hook a piece of fuel line to the fitting long enough to reach a container. Turn the key to power up the pumps, and you should get a strong , full stream of fuel(25-30 psi if you have a gauge) If the pumps are running , and you have no , or little pressure, the filter could be clogged, or the pressure regulator bad. But the symptoms you described dont indicate either. Good luck
Later
Ed
.Got the Hose in the tank and once again I heard only a click like it had power. But not running the pumps, it was the same thing on both Fuel Tanks.... Got the tool today to change the Fuel Filter..so I'll give that a try but I think the problem will boil down to WHY are both pumps not working, they have power I have verified that,, what would send a signal to run or stop the Fuel Pumps...

Got the Hose in the tank and once again I heard only a click like it had power. But not running the pumps, it was the same thing on both Fuel Tanks.... Got the tool today to change the Fuel Filter..so I'll give that a try but I think the problem will boil down to WHY are both pumps not working, they have power I have verified that,, what would send a signal to run or stop the Fuel Pumps...
If you have power to the harness connector at the tanks, then the problem could be the ground for the circuit. The power to the pumps is controlled by the ECM, if you have power back to the tanks, this is ok. Disconnect the harness at the tanks, and using the truck battery or a spare( lawn mower battery will work for this) , hook jumpers to the connector that goes in each tank. The two smaller wires are the sending unit, the larger(red or brn/wht + ) and orng or blk i think , are power for the pump. Just check the other side of the connector to be sure. If the pumps run with the jumpers in place, then the connector, wiring from the switch to the tanks, or the ground for the circuit are bad. If the pumps still wont run, hook a ground wire to the pickup tube assbly. , and the + to the harness , and retest. Since you said you have power, and neither pump will run, i suspect the ground. Like you said, both pumps going bad at one time are unlikely.
Later
Ed
.

Have you tried to see if you have spark?
Maybe the ignition module is shot or the hall effect swith in the distributor is not sending pulses.
You should go to Wally-Mart and buy a code reader and a Haynes manual - that's a cheap investment.
Good luck bud!

Have you tried to see if you have spark?
Maybe the ignition module is shot or the hall effect swith in the distributor is not sending pulses.
You should go to Wally-Mart and buy a code reader and a Haynes manual - that's a cheap investment.
Good luck bud!


Got a good spark and a Haynes manual. Although I wouldn't reccommend the Haynes Manual to anyone...Its very Vague and talks in general terms (staying with Chilton)...As for the truck, I did the Sharder Valve check that Unclebuddles (above) described...GOT NO FUEL coming out...basically starting a process of elimination. Change the Fuel Pressure Regulator (still won't start) Everything still points to the pumps...Gonna change the Filter Tommorow tried to do that myself, It takes a special tool and some experience to do.. I Tried it, couldn't geter done, so calling in the big guys..after the filter I moving on to Check the wiring at the pumps..as described above. trying to maintain a good attitude but this truck is Got me on the Ropes :) thanks for the help..

We have succeded...The trucks runs..
We started this morning with verify the pumps worked..Took to push pins and probed the Hot/Red and Ground/Orange, then hooked up a small battery charger on the pushpins and the pumps ran fine..So that started us tracing power..This is were the Chilton manual (Greatly helped out) The Fuel schematic saved the day. Finally traced the power with a test light from the Relay Distro Box thru the inertia switch to the Fuel Selctor switch on the Dash and suprise suprise. The Fuel selector switch has 4 wires atttached two for the Fuel Guage and 2 from the inertia switch to Pumps..We jumpered the intertia to pumps and she started right away. I orginally thought that since the Fuel guage worked the switch had to be good...so much for logical thinking...But all in all I learned a lot and want to thank everyone who replied for the awesome help..
Thanks for all...espciaclly UncleBuddles..Ed