Starts stalls then hard to start

[1Turbo10]

Hi all need some help. My 87 6.9 was running perfect. Every mourning hit the manual glow for 12 seconds start and go. The other mourning out of the blue when I started it, it started and died. Had to crank the crap out of it. I even had to use some starter fluid. Once running it ran perfect with no problem restarting. Let it sit for enough time (onernight) and the same thing happens. I assumed it had to be air getting in so I made sure everything was sealed tight and dry. There is no wet or moisture anywhere that I can find. Any ideas?

 

[The Warden]

You might check the return hose coming off the top of the fuel filter assembly. I had a crack in mine when I first got my truck (the crack was almost hidden by the hose clamp), and this allowed air into the fuel system without really making for any leaks.

Just a thought...good luck!

 

[Michael Fowler]

Got to be air in the fuel somewhere. Besides the hose mentioned by Warden, check the rubber donouts on each end of the steel pipe that runds from the filter head to the IP. These are known to crack and leak with time.
Is there wet fuel lying on the valley cover?

 

[1Turbo10]

Thanks. I removed the return line and soldered a spot where it was rubbing just in case. I also tighened up the junction block on the end. I also cut back the braided return lines to make sure they sealed good. The valley pan is moist but I think its from me pushing the bleeder checking for air. This is frustrating because every time I think I found the problem I"m wrong. I will ck the fuel filter connection but it is all dry. How sensitive is this system?

 

[MARQ2277]

Ya, anytime you have any type of starting issues, it can only be two (2) things. One, you are not getting fuel, wrong tank, pump, filter, line, etc., or you have air in the system, return lines, ran out of fuel, tank switching, filter, forgot to close water valve, etc. It is real easy on out IDI, without all the electrical, it boils down real fast. Be sure to check that you are getting power to the injector pump, if it stops all together.

Marq

 

[1Turbo10]

Is there a good way to narrow/diagnoise problem? does the fact that it starts and runs great all day narrow it to the return line system? Will a clear line in the return line from pump show air? I would like to consintrate my efforts if possable.

 

[MARQ2277]

You are right. You don't want to be looking or wasting your time if you don't need to. Without being there, and hearing what you said, that it was running, and starts, and quits sounds like air, and a lot of the times, the "O" rings start to leak in the return line caps, or you may have a return line leaking. Look to see if you have fuel leaking any where. If you have fuel, or a wet spot on any line, injector, return cap, there's a good chance if it leaks, it also sucks air, and sucking air will cuase your issue nine out of ten.

check for leaks or wet spots first.

Marq

 

[blink_man24]

I've been having the same problem with my '93 IDI. I thought it was the fuel filter i replaced but it always is full when i check it. I'm gonna check out my lines today.

 

[hesutton]

Thanks. I removed the return line and soldered a spot where it was rubbing just in case. I also tighened up the junction block on the end. I also cut back the braided return lines to make sure they sealed good. The valley pan is moist but I think its from me pushing the bleeder checking for air. This is frustrating because every time I think I found the problem I"m wrong. I will ck the fuel filter connection but it is all dry. How sensitive is this system?

Are you opening the schraider valve on the fuel filter head with the engine cranking over or not? If you are not cranking the engine when you open the bleeder on the filter head, you will only let more air in. Only open that valve with someone cranking the motor over and with the fuel shut off solenoid unplugged from the injection pump.

You likely have a leak at the return line caps on the injectors or in the lines themselves.

Heath

 

[MARQ2277]

Let us know what you find out. That way we can always help out the next guy. Let us know what you did to find the issue, what the issue was, and what you did to resolve the issue, even if you use things we suggest, like looking for wet spots and/or leaks.

Marq

 

[1Turbo10]

I did not have any time to work on the truck today. I plan on tackling it tomorrow, I will let you know what I find. It will be tough with everything being totaley dry. I am not a parts changer but it looks like I might just have to start replacing seals. I would have thought this type of problem would have come on slowly instead of all of a sudden. Thanks for all the input. John

 

[Pipeliner_86]

Just make sure you are'nt using either if your glow plug system is still factory stock. You could put a piston thru your oil pan.

 

[1Turbo10]

Ok, heres the fix. What the problem turned out to be was a bad injector bleeding air into the return lines. The way to diagnoise this is to block/plug the return line going from the pass side front injector #2 up to the top of the fuel inlet tube at the filter. Seems a faulty injector can bleed air in at that point causing a very hard start condition. Blocking or plugging return line will answer the question and hopefuley keep someone else's hair in place. !!!