Hi all
my 86 f150 302 efi ran completely out of fuel and wont start again. I put about a half tank in and tried starting it and it wouldnt. I disconnected the fuel line and had someone turn on with the fuel pump and fuel came out. How would i go about repairing this? Should i try spraying starting fluid into it and then maybe thatll pop it back over and start? Should I disconnect the fuel rail shrader valve as it may have air in it and put it back in?

 

If you have fuel to the fuel rail, as long as the pressure is correct, it should start. Any air in the system should be pushed back to the fuel tank to be vented out. If I understand how the system works, correctly. But I'm not an expert.

Can you measure fuel pressure ?

Where did you disconnect the fuel line at ?

I ran mine out of fuel years ago, I had a gas can with me, because I knew it was very low, after putting gas in, it started right up. Now I did this within a few minutes.

Are you sure you have spark ?

 

Max, he mentioned a Schrader valve on the fuel rail. On my diesel I have a Schrader valve which is handy for purging air after replacing the fuel filter. Is that the location the OP can check for fuel and pressure? Can he turn on the key and purge air there? I'm just wondering if he's air locked?

 

Yes the 302EFI has that valve on the fuel rail. I believe the only purpose for it is to check fuel pressure. But again, I'm not the expert.


Maybe Gary's site under this, may help. The OP can look around that section, documentation, for more info.
https://www.garysgaragemahal.com/198...justments.html

 

Thinking more about it, I think that might work. The high pressure pump would just refill the rails if that pump is working. That's why I asked where did he break the line loose ? Is he sure the high pressure pump is working ?
Did the fuel spray out under pressure, like 35psi or did it just come out.

 

Where did you disconnect the fuel line? Your truck has two fuel pumps, one in the tank or tanks, and one on the frame rail. So if you have dual tanks you will have 3 fuel pumps. Best thing to do is check it on the fuel rail for fuel.

 

The system is self priming. Did you try cycling the key from OFF to RUN a few times before starting?

 

If you get in your truck, buckle the seat belt and close the door. Then turn the key to "ON", you should hear the high pressure pump run for about 3 seconds. The high pressure pump is under cab, below the driver's feet.

 

It's tempting to push the gas pedal after running out. But don't. Let it sit for a minute and then follow standard starting procedure which is turn the key and crank for 4 second and rest it.

 

I disconnected the line near the firewall and fuel came out when I clicked it over, I have good fuel pressure and spark as I just recently checked these before this happened. Also yes, I did click it to run a few times before starting. I do hear the pump running when I click it to the run position

 

Than maybe try to see if you have fuel spraying out when you push in the schrader valve. I believe the pressure should be 35psi. You can buy a fuel pressure test gauge from places like Harbor Fright if you want to go that route.

I'm sure if you google, how to test fuel pressure on a 1986 Ford F150 302EFI, you'll find a video.

 

All the gas EFI systems I have seen purge the air out as long as the pumps are working.
Diesel is a different story and you need to really work to get the air out of the system as I had a diesel at one time.

I think as someone said just turn the key on and off a few times to get fuel to the injectors.
Dave ----

 

I noticed a minor typo in your comment quoted above. Instead of "I have good fuel pressure and spark...", I'm pretty sure you meant to say "I had..."

Present tense versus past tense, very important here. You've tried all the easy stuff, in hopes of a quick fix. That didn't pan out, so it's time to check the basics again, such as fuel pressure. It’s now immaterial if you had checked these systems recently. At least one is presently kaput.

No matter how recently your finger may have been calibrated, don't rely on it for a fuel pressure reading. That's the kind of Hail Mary stuff you do by the side of the road trying to get home. Take the time and do it right, with an actual pressure gauge.

You can also do the starter fluid test. A quick burst, maybe 3 second max, into the inlet duct. Hit the starter and see if the engine responds to this alternate supply of fuel. You're not actually trying to start the engine, only seeing if it responds. If the engine runs briefly (until the starter fluid is consumed), then you know the ignition is good and you've got a fuel supply problem. If no response, you've got an ignition problem. One caveat, make sure the plugs aren't flooded with fuel or otherwise fouled, as that could lead you to mistakenly believe the ignition system was dead. I do not care to discuss how I learned this...

Also, with starter fluid, don't keep spraying and hoping and spraying and hoping. If the engine doesn't respond to a small quantity of starter fluid, more is NOT better. Figure out why the engine didn't respond and correct that. No point is singeing off your eyebrows.

 

You can also pull a sparkplug or two and see if they smell like gas and look wet. If they do, they are fouled and won't fire. You can take brake cleaner and try to clean them up and then put them back in and try it again. All this messing around may have caused some circumstance to where they got fouled. After that, it's not going to run.