Injection pump woes I think

[Garagefull]

I recently acquired an m1031. Unfortunately I inherited the truck from my father, and it had sat unstarted for several years. It started right up with two fresh batteries.I noticed right away that when letting off the throttle that the truck felt as if it was going to stall. It also felt like it was catching up so to speak when letting off and reapplying the fuel. I scoured the forums and checked fuel delivery, air intrusion and adjusted the idle a bit higher. After approximately 500 miles,I noticed that the motor was slightly louder than normal, and down slightly on power. The idle seemed as if it was lower again. No signs of black flecks anywhere internally in the injection pump. Time for an injection pump? I have a reman HD civilian pump, but really didn't want to change it if not necessary. Thanks for any input.

 

[sandcobra164]

Since the truck sat for some time, I would change the fuel filter and run it a little more. I noticed you've put 500 miles so that should likely rule out most of the stale fuel that was in the truck. I'd also try your favorite fuel additive to aid in cleaning out the system. I recommend the Stanadyne additive and normally find it at Tractor Supply. When checking for black flecks did you remove the top cover from the injection pump? If so did everything appear clean and tidy in there? I recently installed a new injection pump on my truck as mine had the flecks and a host of other issues. As you can imagine it cured my problems and runs like a new truck. Prior to changing the injection pump I replaced the cartridge type filter to a spin on type and replace all of my rubber lines while troubleshooting / parts swapping. I like to start cheap and dig deeper as necessary.

 

[cucvrus]

Also check the right side of the pump. See if the lever on the side is moving freely. It runs up and down on the right side and pushes a small plunger. I don't know the technical term. But if you can clean and lube things on the side of the pump it may run a bit better. Only a suggestion. NOT a cure. I have plow trucks that get sloppy wet with salt water and they get a bit tight in the linkage after setting over summer. Mr Rusty just had the same symptoms and some oil on the throttle linkage at the injection pump and driving it seemed to straighten it out. Just a suggestion. Use oil not spray. Good Luck.

 

[Gunfreak25]

Most CUCVs dont have the plastic governor ring retainer, that was a pre 1985 Stanadyne design.

If it sat for several years, I'd suspect fuel tank issues. Maybe algae?

Louder engine as in how? More diesel clatter? Fuel inlet pressure has a direct effect on pump timing, higher pressure means more advance timing.

I've torn pumps apart with enough varnish from sitting that theres no WAY they would have run if put on engine, not correctly anyway.

I'd throw a algea treatment in, drive for awhile
THEN change the filters.

Sent from my SM-G955U using Tapatalk

 

[Garagefull]

I will be sure to check those linkages tomorrow. I know which arm you are talkin about and never thought to check it.I do I had used a can of stanadyne additive that came with a reman pump that I bought several years ago. It seemed to be a very good product and I will be sure to give it a try.

 

[Garagefull]

Well, a flashlight inspection shows that it is leaking around the throttle shaft after today's drive. That and it also left a puddle in the garage. Looks like I'll be swapping pumps out this weekend. I have a 2829 4544 to install, and a spin-on filter adapter.

 

[Gunfreak25]

It's not hard to reseal a pump with a 30 dollar kit but if you just want her done and dont mind spending a few bucks, definitely go replacement.

DieselCare on ebay has inexpensive rebuilding services and CUCVRUS as well as others have good reviews.

Sent from my SM-G955U using Tapatalk

 

[Keith_J]

Also check the right side of the pump. See if the lever on the side is moving freely. It runs up and down on the right side and pushes a small plunger. I don't know the technical term. But if you can clean and lube things on the side of the pump it may run a bit better. Only a suggestion. NOT a cure. I have plow trucks that get sloppy wet with salt water and they get a bit tight in the linkage after setting over summer. Mr Rusty just had the same symptoms and some oil on the throttle linkage at the injection pump and driving it seemed to straighten it out. Just a suggestion. Use oil not spray. Good Luck.

That is the low speed timing advance, driven off the throttle shaft cam. The timing advance is also driven by fuel pressure.

I have had great luck with Diesel Mechanic in a Bottle. Just recently too after my 1031 sat for over a year and had the same symptoms. Take the top cover off, siphon as much fuel as possible, then fill up with the Diesel Mechanic in a Bottle. Let it sit for a few hours, then run.

 

[Keith_J]

The green wire on the injection pump is the cold start advance, it overcomes the case drain check valve cracking pressure, around 5 PSI. This further advances timing.

On my 1031, the install of the PTO governor was incorrect and they had put a switched 12 volt line to the green wire, causing the fast idle solenoid and cold timing advance to be always on. This caused a noisy idle, I disconnected this unneeded wire and insulated the breaks. The only purpose of this is overspeed protection where it shuts off the engine if the generator speeds over 2000 RPM. If you disconnect this line, make sure the governor works correctly!!!

Varnish on the throttle shaft will cause leaks, the Diesel Mechanic in a Bottle will solve this problem. The varnish forms at the seal to shaft interface, the shaft moves sideways due to the cam ring for low speed advance. This is a cause for throttle shaft leakage.

 

[Garagefull]

I was unaware of the change on the governor ring. I think I will pull the cover give her a good soak tomorrow. I had never personally driven this truck before it went into storage, so I don't know if this symptom showed up after sitting.

 

[Keith_J]

With the cover off, move the metering valve through full turns to see if it sticks, this is the most likely cause of your problems. Definitely try the Diesel Mechanic in a Bottle. It is a powerful detergent, the best I have found for dissolving varnish. Give it a few hours to work and get fresh fuel.

 

[Garagefull]

Thanks for the advice.The Stanadyne additive snapped it right out of it. Actually I am shocked at how well it worked . It has never ran better. I was not looking forward to changing out in an injection pump.

 

[Garagefull]

After putting about 50 miles on the 6.2 yesterday,the Stanadyne treatment really did it's job.Motor appears to be much quieter, easier to start.Again,thanks for the advice. I hope that tractor supply will restock the stanadyne.. I will be running it as a preventative measure.