I am having a no-start problem with my 1987 Ford F250 4x4, 302 with 4speed. The truck will not start, but it does fire on starting fluid. The spark plugs are dry. I replaced the high pressure fuel pump one month ago after it failed. Up until now the truck was running fine. The truck did't die while running, it just wouldn't start one day after work. I replaced the fuel pressure regulator today with no change. The fuel pump is operating, and I have 41 psi of fuel pressure at the schrader valve. I have good spark at the spark plugs. I pulled an injector wire and it gives my test light a constant light when the key is on, and a quick pulsing light when I attempt to start the engine. Can you offer me any suggestions on what the problem might be? I really need the truck as the snow keeps coming. Help!

 

Wow,

Well you have done yer homework and checked all of the obvious. If it will run on starting fluid then it's not a spark or timing issue. That only leaves fuel as the problem.

Hum, if you have good pressure at the schrader value and it appears that the injectors are getting voltage. I wonder if it's a fuel volume problem. Does the truck even try to fire when you crank it? Have you checked the pressure while trying to crank the engine. Maybe the regulator is allowing to much fuel to return to the tank and not allowing enough pressure to build up in the fuel rail for the injectors to operate.

It would be interesting to know how much fuel is flowing out the return line to the tank.

This is a tough one.

Good luck,

 

It does not fire or fart whatsoever unless you spray in the starting fluid. I am getting 38psi of fuel pressure at the shrader valve while cranking, and 41ps when the key is on and not cranking. I am at a loss here.

 

Man, this is a tough one.

I am not very competent working on injected engines and I hope someone else will chime in.

Do you have a check engine light on? Do you know if your model truck has fault codes that can be read?

I once had a car that acted simular to this. It ended up being a sensor in the air filter box that air flow in the box caused a vain switch to move. The more air flow, the farther the vain moved. Anyway, the connector to this was corroded.

hum,

 

Do you have this problem on both gas tanks? If you have a single tank, have you verified that the in-tank pump is working? Does the truck run ok once you get it started, or does it just not start? I would try to pull the codes and see what comes up. If your '87 is like mine, the check engine light in the dash is not hooked up so you won't know that the computer has codes until you try to pull them. You'll have to use a volt meter or a small test light to pull the codes. If you don't know how to pull the codes, go to this website and click on "Getting Codes" on the left side of the screen - http://fordfuelinjection.com/index.htm

 

The truck starting once since it quit on me. During that time, it ran like a million bucks, with no problems whatsoever until I stalled it plowing my driveway, and that was it. When I put my ear to the fuel rail, it sounds like it may have some bubbles flowing through it. The rear tank has a significant leak in it so I never use it. I was never able to hear whether the in tank pumps worked or not since I have owned the truck. I hear nothing from them. The high pressure pump you can definitely hear. I am not getting any error codes. The truck does not fart in any way. If it was getting gas that was full of bubbles, wouldn't you at least expect it to fart/sputter or something? HELP!!!

 

Ok, I took a 3 foot piece of garden hose and stuffed it down the filler neck of each fuel tank. I hit the key and I hear absolutley nothing. Dead silence except the distant clicks of the fuel pump relay. Ok, this leads me to my next question. Will a truck refuse to start without the help of the low pressure tank mounted fuel pumps???? Me thinks that there might be some dead wiring down there as I hear nothing from both tanks. I believe that it would be quite a coincidence for 3 fuel pumps to die within one month. I think the next thing is to try giving the pumps a 12 volt jumper and see what we get. Is there an easy spot to tie into the fuel pump wiring without having to lower the tanks???? Does the 41psi of pressure in the Schrader valve consist of air pressure, more than fuel pressure??? Gas definitely squirts out of the Schrader valve when poked with a pen.

 

Ok, I did this once along time ago on a friends chebby truck with a possable in-tank pump problem. I pulled the fuel pump fuse out and jumpered 12VDC into the empty fuse holder. The only problem will be not knowing which side of the fuse holder is wired to the pump so you will have to try each side. This puts "joltage" right to the pump.

That's a good question you have concerning the 41psi at the rail. How it's generating that much pressure and not firing is beyond me. You could always disconnect the return fuel line at the fuel rail and then connect up a piece of hose going to a bucket. Then turn the key on and there should be a strong flow of fuel. At least this would confirm fuel is in the rail.

 

If you get that much pressure at the rail, I would think the injectors are not firing.

And you should hear the in tank pumps run without shoving a hose in the tank, just slide underneath and have the ignition cycled and listen for the 2 second buzz at each tank.

I think if it's an EFI problem, you should check it for codes first off as the solution might be right there!

 

UPDATE::::: I got the old girl running again. I ran a jumper wire to the front in-tank pump (red positive, orange negative), reset the computer, and she fired right up. The wiring in this truck seems to be full of gremlins so I ended up wiring both pumps to the ignition so when the key is on, the pumps are on. This truck has 265,000+ hard miles on her, and she is back in business, ready to plow for another 17 years. Thanks to everyone for their insight. This newbie really appreciates it. Thanks again.

 

Hey that's great news!

Congrat's and welcome to the forum.

Take care,

 

Be careful straight wiring them like that. Should you ever get in a wreck and burst fuel lines, the pumps would not shut off and would create a fire hazard. When you have time, after plowing season I guess, I would re-wire the factory system, with the relay and the inertia switch inline.

 

Also having both pumps running at the same time is not good either.

Hook up two toggle switches to the output wire from the enertia switch (hot all the time on most if not all) so it will cut off in an accident and you can choose which on is on.
Also, if both of the pump switches are off, no one can drive off in it!

 

Rear tank is never in use. It has a substantial hole in it.

I hard wired the pumps (front tank and high pressure) as a test only. I will be routing the wires like it was from the factory when it is light out.

I just wanted to see if getting the front tank pump running would solve my problems.

Thanks to all for the help. I appreciate it!