1990 F250 7.3L startup help
 

Greetings,
Apologies if this exact scenario has already been covered. If it has, please post the thread title or links, as I could not find it!

So here goes:
Startup was getting harder and harder, and the "warm up" light was only staying on for approx. 2 seconds.

To counteract that, I just put in new glow plugs (motorcraft) and replaced the fuel return lines, cups, and o-rings and copper washers on the injectors.

After I fixed the threads on the adapter on the number 1 injector 😒 and got the small fuel leaks fixed, the truck ran great, and starting was right on! Warm up light stayed on for about 15 sec before it went off.

Drove it last night around the block, and then about 15 miles this AM. After sitting for approx. 20 min this AM, I went to start it, and the "warm up" light only stayed on for approx. 3 sec, and the truck was hard to start again.

Any ideas and suggestions as to what else might be going on are appreciated. Thank you!

Are you still running the Factory style fuel fitler ? ( the one with a fuel bowl on the bottom .. ) ?

If so .. Go to napa or your faveriot car parts store .. ( BF-1222) use this number to get a better filter assembly ... the factroy unit often will suck air and or cause issues with run ability :c:.. keep posted :pca1:

Guessing fuel issue now
 

I do have an aftermarket filter, but I too am now guessing a fuel supply issue. I replaced the glow plug relay last night, and now the timing of the plugs being on seems reasonable. Startup still takes 3 times or so if the truck has been sitting for more than hour. I can only get it to start by pumping on the "gas" pedal. So.....air in the fuel lines? Is there a primer pump? Will fuel leak back into the tank?
Any help is appreciated.
Thank you!:hellox:

If you are getting air in the lines, holding the pedal down will help purge it while cranking. Some guys have installed primer bulbs in the fuel line to help with this issue. You can also convert to an electric fuel pump as well.