M818 won't start. Is it my injector pump?

[zachakamp]

I bought a 1970 M818 5-ton about a year and a half ago. I just bobtail around town maybe once every 3 or 4 weeks with it. I haven't had any issues with the truck up until now. I was sitting at a stop light, and when I went to take off, it died. It took a bit of cranking, but it started up and seemed to idle fine, but as soon as I'd tap the accelerator, the engine would die. Once I tried the hand throttle and was able to get RPMs, but as soon as I tried to take off...dead. Each try got worse, and now it will not start at all. I keep my fuel tanks full, and I double-checked. I went through the process to bleed air from the line, but that didn't seem to be an issue at all. Any thoughts?

 

[R Racing]

Possible clogged fuel filter. There is also a screen in the injection pump under the big cap. Its extra fine.

 

[MyothersanM1]

Also, check all your fuel (supply) lines particularly around the fuel tank selector valve. The selector valve is notorious for these problems and is usually the culprit or something in its near vicinity. Make sure you are not drawing air through rotted fuel hoses, lines or loose connections. My truck had the same issues shortly after I got it. It seems to be a degenerative thing as you drive a truck that has sat for a while.

 

[zachakamp]

I checked the suggestions, but no luck. The fuel filter is nearly new. Fuel is getting to the engine (at least via the primer pump). I had absolutely no signs of diminishing power up until it died. I had driven it about 2 miles that day and it seemed great until I tried to pull away at the stop light.

 

[Sephirothq]

Check the small screen in the injection pump.

 

[indy4x4fab]

For some help finding these parts and pricing on the parts from cummins, check here http://www.steelsoldiers.com/5-ton-up/73883-planning-my-m818-recovery.html post 18.

 

[flat tire]

Just had the same exact problem 2 days ago and it was the fuel filter. One of my tanks had bad algae growth.

Worth a shot, my filter was 39 bucks

 

[johndhorse]

We had that happen to one of our M818 and it ended up the solenoid for the electric shutoff had gone bad.

 

[indy4x4fab]

We had that happen to one of our M818 and it ended up the solenoid for the electric shutoff had gone bad.

It's easy to rule out the electric fuel shutoff solenoid, theres a thumb screw on the solenoid that by-passes the solenoid, now if you do this the only way to shut the truck off then is to pull the emergency stop handle. after doing so you will have to manually reset the fuel shut off valve that it activates, and thats very compleated and hard to do.

step one open hood step
two place safety on hood
step three follow cable to valve step four push valve with one finger back to the open position
step five close hood

like I said very hard to check.

If there still isn't a change then turn thumb screw back out to the standard operation position.

 

[MyothersanM1]

Are all the rubber fuel lines still original to the truck or have you changed them out? I was also getting idle and I could increase RPMs at a stand still. The minute I tried to put any acceleration behind it there was a complete loss of power and sometimes stalling. I replaced everything rubber from the IP back to the fuel tank and changed out some well worn brass fittings. I do not have a selector valve anymore as I have downgraded to one fuel tank, so everything is pretty much straight-lined now.

 

[zachakamp]

Thanks for all the advice. I'm going to try replacing the fuel filter again as soon as I can get one. One more thought: Like I said I was able to start it and idle right after it died the first time. It would idle just fine, but died if I would just barely tap the accelerator. After a couple tries at accelerating and dying, it would no longer start. I did get it to start one time later with some ether. It idled for about a minute and then the fuel ran out and it sputtered to a stop. I thought about maybe bypassing the tank switch as well. It just seems weird to me that it would idle so nice that first time, but hardly tapping the accelerator (in neutral) killed it instantly.

 

[indy4x4fab]

Thanks for all the advice. I'm going to try replacing the fuel filter again as soon as I can get one. One more thought: Like I said I was able to start it and idle right after it died the first time. It would idle just fine, but died if I would just barely tap the accelerator. After a couple tries at accelerating and dying, it would no longer start. I did get it to start one time later with some ether. It idled for about a minute and then the fuel ran out and it sputtered to a stop. I thought about maybe bypassing the tank switch as well. It just seems weird to me that it would idle so nice that first time, but hardly tapping the accelerator (in neutral) killed it instantly.

I actaully got rid of my fuel solector valve and went back to the multi-fuel 5 ton set up, with a transfer pump, where it pumps fuel from the right tank to the left tank. and set my engine up to suck from the right tank only. This set up worked just fine in the multi-fuel 5 ton for how long now? I used a mep-003a fuel pump I got used for $20, it has a screen already in side of it that you can remove and clean as needed. every simple set up.

 

[autoshopteacher]

I will echo the rubber fuel line deterioration fix. Had a similar problem and looked at the lines at the selector valve. All looked OK so I unhooked lines from filter inlet and from each tank. I pressurized the lines with air to unplug. I noticed slight weeping from the lines after pressure, indicating leaks. Not detectable under vehicle operation, but there none the less. A trip to NAPA and I got new hoses built. No problems since.

 

[73m819]

Another thing, make sure the FLAT square washer on top of the fuel filter is FLAT and in the recess on top of the filter, if not flat OR not in the recess, OR not flat and not in the recess, you WILL suck air past the O-ring

 

[MyothersanM1]

Another thing, make sure the FLAT square washer on top of the fuel filter is FLAT and in the recess on top of the filter, if not flat OR not in the recess, OR not flat and not in the recess, you WILL suck air past the O-ring

Switch to a spin-on fuel filter set-up, you'll never regret it.