6.2 on its way out?

[erasedhammer]

Engine isn't maintaining idle and appears to be missing at times. While driving sometimes it will seem as if the cold advance was turned on and suddenly I have extra power because of the timing change. When at stop lights the truck is vibrating, and it does miss, just one time, nothing too bad. Under load/acceleration/high rpm it is fairly smooth.

Video of the engine idling after being warmed up after 15 mile drive:

Injection pump? Fuel quality? Internal damage?
When I had the oil pan off the inside of the cylinders and underside of the pistons looked almost brand new. Odometer shows 14k miles, but I dont know what the military did.

 

[dougco1]

Engine isn't maintaining idle and appears to be missing at times. While driving sometimes it will seem as if the cold advance was turned on and suddenly I have extra power because of the timing change. When at stop lights the truck is vibrating, and it does miss, just one time, nothing too bad. Under load/acceleration/high rpm it is fairly smooth.

Video of the engine idling after being warmed up after 15 mile drive:

Injection pump? Fuel quality? Internal damage?
When I had the oil pan off the inside of the cylinders and underside of the pistons looked almost brand new. Odometer shows 14k miles, but I dont know what the military did.

Does it puff any smoke when it skips or surges? It sounds fuel related. Bad/sticky injector? Bad injection pump? Other than the surging the engine sounds strong and I would lean towards a bad/sticky injector.
Another thought, Try unplugging the cold advance wire when its warm and idling. Maybe the temp sensor is going bad and advancing your pump timing randomly.

 

[erasedhammer]

Does it puff any smoke when it skips or surges? It sounds fuel related. Bad/sticky injector? Bad injection pump? Other than the surging the engine sounds strong and I would lean towards a bad/sticky injector.
Another thought, Try unplugging the cold advance wire when its warm and idling. Maybe the temp sensor is going bad and advancing your pump timing randomly.

No smoke at all.
The previous owner removed the high idle solenoid and cut the wire to it off at the cold advance. The cold advance is still hooked up to the temp sensor but the glow plug module is removed as I installed a push button for the glow plugs.

 

[cucvrus]

I would say injection pump issues. Get it rebuilt at a reputable shop. It costs about $500. to do in parts. Good Luck.

 

[erasedhammer]

I would say injection pump issues. Get it rebuilt at a reputable shop. It costs about $500. to do in parts. Good Luck.

Know of any rebuilders around dc/maryland? I can never find anyone willing to touch these pumps. Any shop that I mention a 1986 chevy k30 runs to the hills.

 

[antennaclimber]

Try Oregon Fuel Injection. I have purchased a few pumps from them with great results.

 

[erasedhammer]

Try Oregon Fuel Injection. I have purchased a few pumps from them with great results.

Any local to dc/maryland? I am stationed in maryland right now.

 

[dependable]

If you want to evaluate the overall mechanical condition of the engine, a simple compression test will tell you a lot. But I agree with others here that problem sounds fuel related, and likely the IP.

 

[cucvrus]

Know of any rebuilders around dc/maryland? I can never find anyone willing to touch these pumps. Any shop that I mention a 1986 chevy k30 runs to the hills.

I have been using DCP https://dieselcare.store/collection...-service-for-1983-1994-6-9l-7-3l-ford-idi-db2
Never had a problems. Right now I am waiting for one to come back. The best thing I seen recently is that they replace the metal nomenclature tag on the pump with a date and new tag. Best thing I seen in years. It will stop the BS of I just replaced the pump. https://www.steelsoldiers.com/threa...recked.173878/page-35#lg=post-2296572&slide=3
I had guys drop off their CUCV's and swore the injection pump was just replaced. Being a NOS or take off does not count as a fresh rebuilt injection pump. I want to see the data plate with the date going forward. That little pump makes the CUCV a good vehicle or it will make it a dog and very unreliable. Be Safe and Take Care. Change the lift pump when you change the injection pump. Its a simple task. You would not believe the nasty stuff in the bowl of an old lift pump.

 

[erasedhammer]

I have been using DCP https://dieselcare.store/collection...-service-for-1983-1994-6-9l-7-3l-ford-idi-db2
Never had a problems. Right now I am waiting for one to come back. The best thing I seen recently is that they replace the metal nomenclature tag on the pump with a date and new tag. Best thing I seen in years. It will stop the BS of I just replaced the pump. https://www.steelsoldiers.com/threa...recked.173878/page-35#lg=post-2296572&slide=3
I had guys drop off their CUCV's and swore the injection pump was just replaced. Being a NOS or take off does not count as a fresh rebuilt injection pump. I want to see the data plate with the date going forward. That little pump makes the CUCV a good vehicle or it will make it a dog and very unreliable. Be Safe and Take Care. Change the lift pump when you change the injection pump. Its a simple task. You would not believe the nasty stuff in the bowl of an old lift pump.

Which stanadyne model db2 comes stock with the CUCV? Is it by year or just all years? I'm not sure what model is on my truck, ill have to take a look later.
$400 for a reman replacement seems like a good deal though.

I have a fresh lift pump, filter, and glow plugs in the truck. IP should be the last thing to make it last a while.

 

[cucvrus]

I never went into much details. This is the new tag that was on the pump. https://www.steelsoldiers.com/threa...recked.173878/page-35#lg=post-2296572&slide=3 It runs great and had lots of power. Good Luck. Seattle is a bit far for me to travel to assist. Good Luck. Get the new J code intake gaskets.

 

[german m1008]

.......

 

[joshuak]

Know of any rebuilders around dc/maryland? I can never find anyone willing to touch these pumps. Any shop that I mention a 1986 chevy k30 runs to the hills.

http://www.jgparks.com//products/12/Injection+Pumps.html

Authorized Stanadyne dealer in the area (Maryland), they quoted me 750$ for a rebuild, if I remember correctly.

 

[cucvmule]

Engine isn't maintaining idle and appears to be missing at times. While driving sometimes it will seem as if the cold advance was turned on and suddenly I have extra power because of the timing change. When at stop lights the truck is vibrating, and it does miss, just one time, nothing too bad. Under load/acceleration/high rpm it is fairly smooth.

Video of the engine idling after being warmed up after 15 mile drive:

Injection pump? Fuel quality? Internal damage?
When I had the oil pan off the inside of the cylinders and underside of the pistons looked almost brand new. Odometer shows 14k miles, but I dont know what the military did.

Could be as simple as sucking air into fuel system. What do the rubber fuel lines look like? Have you checked the clamps on the fuel lines for being tight? Have you used a clear fuel line from the pump to the fuel return line to see if there are air bubbles in the fuel?

When you changed fuel filter did you do an autopsy on it to check for contaminates?

Do not assume anything.

 

[erasedhammer]

Could be as simple as sucking air into fuel system. What do the rubber fuel lines look like? Have you checked the clamps on the fuel lines for being tight? Have you used a clear fuel line from the pump to the fuel return line to see if there are air bubbles in the fuel?

When you changed fuel filter did you do an autopsy on it to check for contaminates?

Do not assume anything.

I replaced all the rubber hoses recently, it's all fresh.
The old filter was the box style and as far as I could tell the fuel that drained out was free of contaminants

 

[cucvrus]

This is the old dance around the real problem tradition. I am only saying this because I know that people in general like to avoid the ultimate answer and solution for monetary reasons. Been there and done that. The real issue is if you didn't replace the injection pump yourself with a known new rebuilt fresh one then that would be the correct path to travel. Do it now rest knowing you done it right the first time and travel on for many years and miles to come. All sorts of witch hunts take place on this topic and in the end it comes up as a worn out injection pump. And I don't like spending the money either. I never spent the time (time is money) trying to avoid the inevitable. That little pump fixes a lot of ill's in a diesel engine. Good Luck.

 

[erasedhammer]

Well it looks like the injection pump has up and completely died.
Cranks but absolutely no start and NO SMOKE.

Just in time for the cops to show up and say it's disabled and will be towing it away in 48 hours.

 

[dependable]

If it were my truck, I guess my focus would be try to get off street somehow, at this point.

 

[erasedhammer]

If it were my truck, I guess my focus would be try to get off street somehow, at this point.

Called the police, they said the best chance I'd have is to move it down the street. Unfortunately I live in an HOA that will also tow the vehicle if it enters the neighborhood. Something about green trucks are not allowed....


Very annoying that the truck went from running decent, to completely dead after sitting for a few days.

 

[erasedhammer]

I cracked the injector lines open and they were pretty dry. Bled them (6/8 ) and the engine fired right up. Running smooth without hiccups after warming up. Surprisingly the engine would not fire up with only 4/8 injectors bled.

Prior to my original post, I had just replaced both the send and return fuel lines from the tank. The return line was left open for about an hour while I made up some hose.
I'm not sure if the injection pump or injectors are to blame or just air working its way out of the system (specifically the return lines).

Could an open (unsealed) return line cause all the fuel to back out of the main injection lines?