86 F-150 5.0 EFI. Started one day ran fine then just shut off. Would not restart. Fuel pressure key on engine off (KOEO) 10psi first prime, 20+ second prime, 40 on third prime. 40psi while cranking. All fuel pumps running. Has spark. Replaced coil, ICM, plugs, wires, cap and rotor, TPS, and pick-up coil. Timing is correct. Firing order correct. Only codes were ACT and EGR. Stuck please help.

 

After a cranking session pull one of the plugs. See if it's wet with fuel or dry.

 

Thanks for the reply Dave. I will pull the new plugs and check. When I changed the old ones they were damp, with #1 & #4 being the worst. Also I am getting voltage at ICM harness, SPOUT connecter, and misc. sensors. Used NOID light on injector and OK. Thinking at first fuel issue tried starting fluid, not a bark. The only time we have had any sign of improvement was after tune-up it briefly, and I mean briefly, acted like it wanted to start. But then just dead crank over and over. I believe timing is correct. At o TDC #1 intake and exhaust valves up, rotor pointing to left of #1 distributor cap pin.
Thanks.

 

Hey Dave,


Pulled #5 its wet.

 

If you are positive you have spark, with a good battery hold the accelerator pedal to the floor and crank it. See if it tries to start or does start. Holding it to the floor while cranking will turn the fuel off to the injectors. It puts the computer in a "clear flooded engine" mode. If you have good spark, it seems you are getting too much fuel for some reason.

 

I thought of the same thing as well. Did not work. Just dead crank. Tested spark at coil wire to distributor and at plugs with calibrated spark tester. Blue spark. But that was before tune up. Will check again. Thanks.

 

Have good spark at all locations. Plugs wet after cranking session. Is fuel pressure supposed to be 35-45 at KOEO? If so I don't have that. I have 4-10 on 1st prime 10-20 on 2nd prime and 20-40 on 3rd or 4th prime. May be bad high pressure or low pressure pump? Give me your thoughts please.

 

It should jump right up to about 38psi or in that neighborhood. After turning the key on a couple of times, pull the vacuum hose to the fuel pressure regulator. See if it has fuel in it. If the fuel pressure regulator is busted, it can leak raw fuel into the vacuum line, and that can go in the engine and flood it.

While you are doing your fuel pressure testing, pump it up as high as you can get it with the key, and then see how long the pressure stays up. It should stay up for very long time without leaking down. If it leaks down, pump it up again and then take some needle nose pliers or something and squeeze off the line coming from the fuel pump up at the engine. If it stops leaking down, then the check valve in the pump is bad. If it still leaks down, then pump it up again and pinch the return line to the tank. If it stops leaking down, the fuel pressure regulator is leaking.

If neither one of these stops it from leaking down, then you have one or more injectors leaking into the engine.

 

Ok,
Replaced high pressure fuel pump and fuel pressure regulator. Rear pumps deliver 6oz of fuel in five seconds. Have not checked new fuel pressure readings yet, but noticeably higher at schrader valve. STILL NO START! AGH!! This is driving me crazy. Ready to start a bonfire. Bring your marshmallows. Any other ideas? Being that it would not even bark on starting fluid, would it be logical to say it is not fuel related?

 

You said it has spark. You know you have fuel. I was going on the idea that it was flooded and fouling the plugs out. If you have spark it should at least cough (bark) like you said.

Pull the distributor cap off and crank it. The rotor is going around and around when you are cranking correct?

 

Hey Dave,
Thanks for getting back to me. The rotor does turn, counter clockwise. If I turn the crank backwards there is little to no play in rotor/distributor before it starts to turn clockwise. I know that I said there was no bark/cough, but there is a want to start when you try it the first time of the day for a second or two. After that just dead crank all day.


Could injectors just die with no warning while truck was running? How many would have to be leaking and/or bad to not make it start?


Could there be a problem with PCM? I have signal/current from it to relays, fuel pump, sensors, harnesses, etc.. I pulled it after no start situation and there is no burnt smell.


I started to think ignition switch, but it cranks, there is good power to ICM pin #4 with S wire disconnected from solenoid, and #2 and #3 as well. Is there another ignition switch wire possibility?


I have always worked on the idea that you need spark, fuel, and air all happening at the right time. But this has me and many others baffled.

 

If you have spark, and squirted starting fluid in it, it should do something. I would double check the spark again. If you have a timing light you could see if it will trigger when you crank it.

I can't remember, but did you try holding it to the floor while you cranked? That will turn the injectors off. If the engine is being flooded, all that fuel will kill the sparkplugs. If they are soaked with fuel, it will not fire at all.

 

I definitely have spark, checked at coil and plugs with calibrated spark tester before and after tune-up. Connected timing light and it works. Tried full throttle multiple times and has not worked. I have not done compression test yet, but as soon as it warms up I will. What should compression readings be? I have 125k on engine. I'm guessing 80-110.


Possible ground issue?

 

Finally found the problem. Decided to do a tear down of the timing gear after noticing strange changes in the timing. Yep shot cam gear. Enough teeth for it to be correct with cranking but then would jump when it would bark. Did this on a hunch after reading about timing issues after 90k on the 302. New timing gear and adjustments and it runs great. Thanks for the help.