A Possible Injector Pump Issue (M1008)

[original]

I have been running WMO for about six months now. I started with a mixture of diesel (20%) and WMO (80%) filtered to 1 micron. I have recently (four weeks) been running a mixture of 85% WMO and 15% RUG. Yesterday, the truck lost power. Full throttle acheived 5 mph and 1/2 mph on hills. I read a similiar thread about power loss that was solved by removing debris from the return fuel line. I am going to replace the firewall filter today and blow out the fuel lines with low pressure. I will also inspect/replace the tank strainer. However, my main concern is with the injector pump. The lift pump is working. After getting home, the truck will not start. Has anyone ever had similiar issues with the IP. I would like to accredit my problem to wmo choking or filter clog, but I'm not very confident in my 70,000+ mile IP. I will open the injector lines and check for fuel. Anyone know of a stanadyne pump rebuild shop around wv. Even if the IP is good, I will probrably rebuild anyway. I hate something that I can't rely on. It's just my luck, the tank is full. Let's get to work now, any information is appreciated. -- Henry

 

[dstang97]

DOnt for get these trucks are 25+ years old and who knows when the last time the IP was rebuilt. Maybe its just me but that is a lot of oil in your mixture. I have heard that 50/50 is the most you should do. Start with the easy things and change the filter, make sure there is no air in the system. and go from there

 

[pmramsey]

I have been running up to a 50-50 split of diesel and used cooking old for three years in several of my M1028s. I have more than 20-25,000 miles on any one of the trucks during the period. We've not have any sort of problem using the oil. In fact, we ran almost 200 gallons through one of the trucks during the last month alone. I suppose you've noticed how much quieter the engine runs with the oil and there's a lot less engine knocking. The oil is a better upper cylinder lube that diesel. The 10-micron fuel filter on the truck should be removing any flour suspended in the oil if your pre-filtering of the oil prior to pouring it into the truck. Please keep me posted as this is a subject that I am most interested in knowing all that I can.

 

[Matt65]

My pump had been leaking for over a year from the throttle shaft. I removed the pump last week and shipped it out for rebuild. I will be updating once the pump returns, which could be today. Thus far I am extremely pleased with Tim at Accurate. There were shops a lot closer to me, but I kept hearing good feedback about his work. I have spoke with him over the phone, and several times through email. He is extremely knowledgeable, and is customer service is top notch.

Be sure to take it easy on your starter as you work through this, re-prime etc. Give it plenty of time to cool between use.

http://www.steelsoldiers.com/members/matt65-albums-injection-pump-rebuild.html

Tim @ Accurate Diesel
Phone: (231) 660-1689
www.AccurateDiesel.com - Accurate Technical Services, LLC

 

[original]

Thanks for the link matt, I have narrowed it down to the IP. The IP shaft cracked, but didn't break completely. I don't think it had anything to do with the 80/20 WMO. I have a tank heater and inline fuel heater on the truck so the fuel reaches 175 F before reaching the IP. At this temperature the 80/20 blend was thinned considerably. It may have caused this old pump to fail. I had my worries about this viscosity of the 80/20 WMO upon startup. That is why I switched to the W85 blend as mentioned above. The W85 is much thinner. I will credit this failure to an old IP which had set for a few years and maybe to the 80/20 wmo blend. I will send it to be rebuilt and continue to use the W85 blend. When poured down the side of a board W85 takes 1/2 a second less to hit the bottom than diesel. I Not to much difference. After the truck heats the fuel it is probably the same as diesel, but I haven't tried it.

 

[mightymanx]

Just a comment

Your posts are virtually impossible to see with a black font on a OD background.

 

[original]

I have vision issues, I can't hardly see the standard format. Sorry, back to the old large white.

 

[original]

I am sending my IP off to be rebuilt. I have two extra 6.2L injector pumps in a box. I grounded them and briefly touched 12v to the terminal where the pink wire goes. Nothing happened. Is this a proper way to test an uninstalled injector pump? I'm going to send one of the extras in to be rebuilt and the other for a small core discount. Any other ways to check an uninstalled IP would be appreciated.

 

[Chief_919]

There is no way to properly test an IP unless it is on the truck or a test stand. Like you described you can test the solenoid, but that is just one part (and an easy one to fix).

Keep in mind around 100,000 miles is where you start seeing failures in these pumps. And if you truck was in service after 95 or so it was run with JP8 insteda of diesel, and that is harder on these pumps as well.

 

[ranchhopper]

Sounds like the check valve in the return line clogged up thats the first sign of a tired pump its better you took it off to have it rebuilt anyways.

 

[original]

I have installed the rebuilt injector pump ($355) and replaced all rubber fuel lines. I'm still having problems with air entering the fuel somewhere. This leads to no power on hills. No big deal, at least I know whats wrong. The pump shop said the the wmo was not to blame for pump failure. I will continue to run the W85 mixture and see how the new pump holds up. I had an extra pump rebuilt so I don't have to much to lose. Thanks for all the help.

 

[southdave]

pump need to be grounded probely why you did hear the solenoid click

 

[SGT Estum]

Any updates on this one? Is you truck running better now?

 

[SGT Estum]

Bump. I'm having nearly identical issues. I'm about to try the snake oil and various additives...

 

[Kid Kodiak]

Properly calibrated Injector Pump

Hey original,

Are you certain that the people who rebuilt your Injection Pump calibrated it properly?

I just had mine rebuilt through Peninsular Diesel and they explained that the numbers stamped on the tag on the IP indicate how the IP is calibrated.

For example: If you sent in a 1982 "C" code Injection pump to be rebuilt and installed on your CUCV, you might be installing an IP rated for 135 horsepower.

The CUCVs are rated for 145 horsepower.


The other side of the issue is that you don't want to install an IP that is calibrated for more than the injectors are designed for. The injectors won't be able to keep up with the output of the IP.

So the IP on my 1985 K20 Suburban is rated for 155 horsepower. It wouldn't be the best replacement for my 145 horsepower M1008.

I, myself, am new to the 6.2L diesel and this is my understanding of what was explained to me.

Peninsular Diesel brought me back inside their shop and showed me a 6.5 block on a stand. They walked me through the entire process of how to replace the Injector Pump on my Suburban. They even had all the gaskets I needed on hand.

For what it is worth, I would highly recommend them as they only deal with the 6.2L and 6.5L.

 

[original]

It sad to say that I still haven't corrected this problem. I installed a clear fuel line to the injector pump to watch for air entering the system. No air entering the lines. I have adjusted the IP timing to no avail. Fuel filter and housing ruled out as a problem. I'm begining to think that I have an issue with injectors. Maybe an injector or two stuck opened. Runs fairly normal on flat ground (like there is any in WV). The truck just bogs down when increasing acceleration up hills. Here are the symptoms: Hard to start after setting for a day. Lots of white smoke at idle. Lots of black smoke under throttle. No power on hills. Truck ran normal before injector pump rebuild and rubber fuel line replacement. Slow and steady I hope to resolve this issue , but please don't watch the thread for a quick reply. This truck is not necessary to me and I just work on it as I find the desire. Thanks for the knowledge.

 

[mightymanx]

What you describe sounds like it could be injector dribble.

 

[original]

Sorry to leave this thread unfinished. I just forgot about it. It was the injectors. I replaced all with rebuilt injectors and the truck is 100%. Still been running the same fuel mix for over two years since I left this thread. Thanks to all.

 

[Warthog]

Thanks for the followup.