7.3L non turbo 1994 F250hard start when warm

[ss72@comcast.net]

this motor starts every day when cold in the morning.after truck has been run for more than 30 min (fully warmed up) and shut off for 1min or longer , the motor will not restart untill the motor cools down ,(at least 4 hrs later), have been to 2 ford dealers and 2 independent techs. no answer to the problem. motor has new glow plugs, fuel lift pump, batteries, fuel filter, 1 new fuel tank. the problem is worse in the summer time. if it was a gas motor i would think it is a vapor lock condition. ss72@comcast.net

[M.L.S.C.]

Injection pump, typical symptom for a failing one. You can verify this by shutting off the engine, then slowly pour water over the injection pump till tis fairly cool to touch - if it fires up right away, you may wanna start looking for a replacement. One thing tho, use lukewarm water NOT ice-cold, also avoid cooling the flange where the pump bolts to the gear housing up front and focus on the injector lines end instead.

[hesutton]

Just based on what you've said, I would also vote that your IP is on the way out. How many miles are on it and the injectors? 100,000 or so and they get tired. You can increase their life with some lubricating additive like Power Service or whatever you like.

Heath

[zpd307]

i saw this yesterday with my truck. i was pulling a trailer for some distance to get hay during the day when it was warm. once it cooled off it started like a champ. once it got dark and much cooler out there was no problems. so how long do you think i might have with this pump. i do not know the exact mileage on the pump and injectors. the motor has around 150k on it so i am gussing it is factory. the problem is i am planning on getting a turbo but not until next spring, too much other stuff to get back up to snuff. when i do, i would be putting on g codes and a factory turbo or upgraded pump. but the truck will be used late november to make 5 1/2 hour trip, one way, up north for deering, pulling a bunch of atvs and a slide in camper. i do have a supposed rebuilt pump that came with the truck when i bought it but dont know if it would be worth it w/o doingthe injectors and return lines. ffrom what i understand, changing to g codes and turbo pump w/o a turbo would not be good.

[Kaliburz]

Have both of you check your starters? Are they spinning the engine FAST enough to get it to start? Takes more 'juice' to spin the starter when the engine is warm.

A buddy had exactly the same issue. Got worse and worse. After a nice short trip, it would crank and crank, then start. Shops were telling him it was the IP and/or injectors. Then one day, no crank. So he puts new batteries (950 CCA from Costco) and starter solinoid (cheap)- nothing. He takes out the starter and has it check.... yup, that's it. IF YOU CAN COUNT YOUR ENGINE REVOLUTIONS WHILE CRANKING, IT IS TOO SLOW. Batteries or starter or both.

Now, he can turn the engine over and not even have to glow plug it after the first start of the day. He has 135K and an ATS turbo on it. Priviouse owner used it for towing.....

If you don't have the gear reduction starter, get it. Trust me.....

The engine cranking speed is VERY important. Trust me. I have a JD 2240 tractor. The orginal Bosch starter and starting setup did not spin it over very fast.... gave symptoms of a weak battery or a bad starter. After adding an Optima battery, a gear reduction starter and a Ford starter solinoid refit (to signal the starter to activate), it spins over like a scalded pig! We could NEVER get it started in the winter w/out plugging it in. Now, you just spin over a bit and she'll fire. If it's really cold, I hit the pre heater in the intake that I refitted for 20-30 seconds. But plugging in is not needed any more.... unless it it's the mid to low 20's.... as the daily high.

[Snotzalot]

Before I would replace the IP I would inspect and test the starter.

[janro03]

my truck is doing the same thing, same truck. did you get yours fixed?

[zpd307]

mine has never given me a problem on short trips, so it was unusual for it to take forever to start the other day after a couple of longer drives. but once it was cooler out, everything was fine again.

[M.L.S.C.]

Guys, water-cooling your IP costs nothing, same with keeping an eye on the cranking speed - gotta do some diagnostics before jumping into a parts shopping spree.

[janro03]

we did test the starter, that was bad. we replaced the starter and the truck started right away when cold.. drove it around, went back to the house waited an hour before tyring to start then same issue... just kept turning over. i guess the next test the ip?

[Snotzalot]

Did it fire at all? When was the lift pump replaced?

[grasshopper7.3]

I'm so pumped you guys posted this....I bought a '93 2 weeks agoand it cranks up quickly in the morning. After a trip to anywhere it takes 6-7 (3) second cranks to fire up. Each time the starter getting faster. I also was told glow plugs and module. It only has 158k on it so I will check starter and battery juice. This is my 1st IDI after 2 Powerstrokes.



DM

[JASTECH]

Mine is doing the same. I arrived back from getting the truck in another state yesterday. When the engine has been run for a while it will start right back up. But if it sits for a few hours but is just warm then it will crank and crank and not start until I use starting fluid.
It has 2 new 1100 cca batteries and spins way too fast to count rpm's. I use Lucas in the fuel. It has 195k miles on it. From reading these posts it might be the IP correct?

P.S. What about plugging the return lines, that will stop the fuel from going back so it will start easier correct?
Blocked fuel return lines.jpg

[Snotzalot]

The return line system is used to cool the injectors, so you can't do that.

[janro03]

ok we are going to test it soon for the ip, i will let everyone know what happens.. need my truck