Signs of pump failure?

[red450ih]

My 83 6.2 has been acting strange lately. It won't idle smooth and while going down the road it will speed up or slow down on it's own. The engine rattle is also louder when it trys to speed up on its own. Are there any tests that I can do at home before spending alot at a Diesel shop? It still seems to start fine. The truck has 90K miles on it and the original owner doesn't remember having the pump or injectors worked on before (I'm the second owner).

Thanks,
Keith

Nashville, Tennessee

 

[DieselDan]

Well it certainly not a "normal" failure for a DS2 pump. Usually they get hard to start (esp. when hot) or just fail all together. Sounds like maybe the internal advance mechanism is failing. The only at home test I can think of would be to eliminate weird stuff like the cold advance (HPCA) by disconnecting the green wire that connects to the high idle solenoid and the spade (HPCA) on top of the pump.

It shouldn't be THAT expensive to have the timing checked by a competent diesel shop (I would think!).

Real trucks don't have spark plugs!

 

[6.2 man]

I always start with easy and work my way up . Change the filters first .Then look at the other .Sounds like maybe it is getting air somewhere in the lines ???Might be the fuel pump ???

 

[red450ih]

I put new filters on the truck and that has seemed to cure the problem. The engine runs quiter and is alot more responsive. There was rust in the filter, so I'm going to buy a new fuel tank in the next few days. Who has the best deal on new tanks? I have a long bed with a 20 gallon tank.

Thanks,
Keith

Nashville, Tennessee

 

[DieselDan]

Good call Red. I didn't think about the filter. That must have been pretty clogged to cause such a drastic surge like that! We run into clogged filters when a unit deploys somewhere and they have to use JP8 instead of DF2. The cleaning effects of JP8 usually just fills the filter so bad and fast the truck just barely idles (if that). I thought about an air leak, but he said it started OK. Air leaks can cause fits of starting problems; ask me how I KNOW!

Real trucks don't have spark plugs!

 

[Hans_de_Wilt]

Can I use on JP8 without problems or do I need an additive ? Does JP8 clean the injectors too ?

Hans.

 

[DieselDan]

The US Army uses it all the time. I wouldn't recommend it though. It's really "dry" (lack of lubrication) and, although I don't have hard numbers, I would venture it's hard on pumps and injectors. At Ft Irwin, CA. I noticed a few HMMWVs with impending pump failures and worked on a few more generators with small diesel Onans that wouldn't run; the injector pump rack would stick closed (a quick oil bath would free it up). JP8 also makes rubber fuel lines gummy. It does clean the fuel tanks. 'Not sure about the injectors, I would think diesel injectors are more prone to wear than fuel deposits (ala gas injectors).

Real trucks don't have spark plugs!

 

[surg82k5]

I know that there is a site that i found on here i can't remember the address but it is something like Coleman surplus.. something like that, i know that they had a 32 gallon fuel tank for a blazer that might fit in your truck and it cost something like $30. I will try to find you the site if you can email me at [email protected] and i will be sure to get the site for you..
Sergio

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