M1028 running problem

[BOBCAT]

I just got an '86 M1028. The previous owner let it run out of fuel, then let it sit all winter long. I filled the tank, put a new fuel filter on it, charged the batteries and it runs well for 40 seconds, then shuts off. It starts right up and runs for 10-15 seconds and shuts off. Starts right up, and runs for 3 seconds, then cuts out.

Any ideas? Thanks.

 

[m1008chevy]

First thing I would do is check if you have any air leaks in your fuel lines. Put a clear tube from the top fitting of your injection pump to the metal return line. The problem I was having with my truck is the fitting on top of the injection pump was stuck, not allowing fuel to flow through which would fill up the top portion of the injection pump with diesel and since it is pressure sensitive, the truck would shutoff after maybe 5 seconds. Took the fitting off, cleaned it, blew some air through the return line and its been running fine ever since. My truck would also blow white smoke. Hope this helps, good luck.

 

[BOBCAT]

First thing I would do is check if you have any air leaks in your fuel lines. Put a clear tube from the top fitting of your injection pump to the metal return line. The problem I was having with my truck is the fitting on top of the injection pump was stuck, not allowing fuel to flow through which would fill up the top portion of the injection pump with diesel and since it is pressure sensitive, the truck would shutoff after maybe 5 seconds. Took the fitting off, cleaned it, blew some air through the return line and its been running fine ever since. My truck would also blow white smoke. Hope this helps, good luck.

Thanks. I'll try that in the morning. I am thinking that it has to be something simple. Maybe annoying, but simple. It was running well before they ran it out of fuel, and runs well now - before it quits.

 

[GPrez]

Try Loosening the fuel line fitting at each injector. Crank the motor till you get fuel bleeding at each injector and then snug them up and try starting. This will help bleed air from the system.

 

[Ford Mechanic]

Hey Peter! Subscribed!

 

[BOBCAT]

Thanks. I loosening one injector (driver side close to the firewall) and cranked it up. The motor "Disneyied" (chity-chity-bang-bang-ed) while I pumped the pedal until my leg got sore and I quit stomping. Then it quit. I will try the other injectors later.

 

[BOBCAT]

Put on the clear line and cranked. Tube had a small, spirit level type bubble right at the top of the tube that allowed fuel to go underneath it. Truck ran for about 5 minutes, then quit. When I checked the tube was filled with air so the beast must be sucking air someplace. Thanks and have a great 4th.

 

[BOBCAT]

OK, here's what's happening. I bleed the system, get it running for a while and it cuts out. The clear line from the IP has tiny bubbles coming from the IP, and the whole thing seems to be sucking air. The new stock fuel filter and old housing etc. is being replaced with a NAPA housing #4309 and a NAPA #3123 fuel filter. I am going to replace all the fuel lines and put a check valve just before the IP. I am also going to put some new, bigger batteries in this beast and I am going to order a new IP solenoid just in case. They do go bad and I have 2 CUCV's so sooner of latter it will be used. I just prefer working on stuff in my garage than on the side of the road in 90+ heat.

Have a great 4th.

 

[rsh4364]

Sounds like you have a good handle on situation,I would also drop tank to clean and inspect filter sock or maybe cam-scope it.And when doing spin-on filter add a fuel pressure gauge.Really helps diagnose fuel issues.

 

[CUCVLOVER]

As Rsh4364 stated add a fuel pressure gauge to the system.
But I would set up two gauges one in cab and one under the hood. That way you can see it while running down the road and while you are under the hood.
Do as wish, hope this helps.

 

[rsh4364]

I kinda like the wix #24770 head and filter# 33005,The head unit has 2 inputs and 2 outputs,makes it easier to add accessories like pressure gauges and such.Head unit is about 33$ and filter is about 21$ at Summit.

 

[Ford Mechanic]

Peter I have a bore cam of it comes to needing to scope the tank. And if it has somewhere to hook up a fuel pressure guage I have one also.

Does this platform have a mechanical pump on the engine or a electric one in the tank?

 

[cucvrus]

I want to mention that you could have a minor fuel leak in the fuel feed line or hose. I have a truck that has the fuel line so rusty that it sweats diesel fuel.(Mr Rusty) Not enough to puddle up but enough to let it drop the fuel and suck air when you do get it started. I also seen the metal fuel lines at the rear under the cab rubbed thru. Check them out. This is a 30 + year old vehicle. It did a lot of vibrating over the years. Check closely. I have a fuel cap that I put an air fitting in and just put a few lbs of pressure in it to check for the seal of the entire fuel system. Crazy idea but it works well. 5 lbs of air pressure find s most leaks quickly.

 

[Ford Mechanic]

I want to mention that you could have a minor fuel leak in the fuel feed line or hose. I have a truck that has the fuel line so rusty that it sweats diesel fuel.(Mr Rusty) Not enough to puddle up but enough to let it drop the fuel and suck air when you do get it started. I also seen the metal fuel lines at the rear under the cab rubbed thru. Check them out. This is a 30 + year old vehicle. It did a lot of vibrating over the years. Check closely. I have a fuel cap that I put an air fitting in and just put a few lbs of pressure in it to check for the seal of the entire fuel system. Crazy idea but it works well. 5 lbs of air pressure find s most leaks quickly.

Alot do the same to re-prime and test the M939 fuel system. We'll have to see if we can get a spare cap.

So I take it this is a mechanical system.

Peter how much fuel has been added to the tank?

 

[cucvrus]

You can do the mod to your present fuel cap. It will not hurt the cap function. Just tap it put the fitting in and remove it and plug the hole or just let it in and live with it. Never do any harm to the system and you can test it and use the air to prime the fuel system.

 

[Ford Mechanic]

Alright guys, I got over to Bobcat ' and looked at this truck. It starts and runs to well to be having a fuel leak sticking air, in my opinion. It fires right off and then shuts down, no stumbling or missing. I belive it has a weak fuel shut off solinoid.

So is this common at all? Is there a quick test to verify? It looks to be inside the housing. Does anyone have a part number for it? I called NAPA and they couldn't find it. Any tricks or things I need to know before replacing it?

Thanks for the help guys, I'm going to try some searches, but tap a talk is a little more difficult with searching.

 

[BOBCAT]

I read someplace that there are only 3 little 5/16" bolts holding the top of the IP on, and having had a bunch of coffee for breakfast and nothing much happening at work, decided to take the top off the IP. I removed about a teaspoon of rusty sand from the bottom of the IP, put the top back on, and the beast fired right up. I backed it out of the garage and let it idle. I drove it around the property and brought it back to the garage where I noticed that the IP was leaking like crazy out of the back under the air cleaner. Tightened it up, it stop leaking and stalled when I put it drive. It would not start and run. Loosened the rear bolt on the IP so it was leaking again and it rand fine. Drove it around again. Tighened it back up and it quit. More work required.

 

[cpf240]

Maybe the return line check valve on the back of the IP is plugged up, causing back-pressure, that is relieved by running it with the cover loose?

 

[BOBCAT]

Unfortunately the check valve seems fine. Are these solenoids 12V or 24 volts?
Thanks!

 

[cpf240]

Should be 12v on a CUCV.

Just for fun, maybe try blowing air down the return line to see if the line is clear to the tank?