Please HELP! 6.2 loss of power

[christrucker]

Hey guys, new to diesels, I have a 83 6.2L van motorhome. It has 65,000 miles. I replaced both fuel filters and air filter. Runs and starts great. The problem seems to be after it is driven a while it losses all power and smokes a bunch. But before that it runs great plenty of power. Trying to narrow down the posibilities. Thanks for any suggestions.
-Chris-

[moondoggie]

Good Day!

Black smoke virtually always means too much fuel (unlikely) or inadequate air (more likely). Soooooo, after running awhile, either your IP is deciding to inject more fuel (unlikely) or something's restricting air flow. I'd take another look at your air filter. Also, if you can drive this thing with the doghouse off, I'd do that & look to see if something flexible in the air intake path is collapsing after getting warmed up (which it might not do with the doghouse off :mad:, making troubleshooting difficult).

Let us know what you find - not many vans & campers with 6.2/6.5's, so your fix will be useful to others through the search feature.

Blessings!

[gmctd]

Good suggestions - also check for nests and other signs that small furry critters like traveling in style, as well.

Also check the fuel return line for blockage, starting with the nipple that is screwed into the top front of the IP

[christrucker]

Here is what I was thinkining might be the problem. Could it be a couple of the injectors just stop working and then it is running on lets say 6 cylindars, so the ones that are working are having to work way harder which is making me floor it and it makes it smoke?

Heres another thought. It is missing the snorkle thing that goes from the front of the van to the air filter, could it be pulling in hot air making it run like that, I could see a little bit loss of power, but not this extream. The motorhome will barely do 55 on the highway floored. WHen it is running good it will do 70 without a problem at half throttle.

One other thing, there are 2 little hoses that connect under the air filter they have a 90 degree angle and go on each side of the motor. When I bought it the one was cracked, I tried to find a new one but couldn't so I taped it up with electricle tape. What are these and how important are they, they could be collapsing from heat, would this cause it?

THanks.
-Chris-

[john8662]

Could it be a couple of the injectors just stop working and then it is running on lets say 6 cylindars, so the ones that are working are having to work way harder which is making me floor it and it makes it smoke?

Not likely, it would white smoke for poor running conditions like this, your engine would lope badly if this were the case (run rough). The symptoms here suggest running rich, for one reason or another...



Heres another thought. It is missing the snorkle thing that goes from the front of the van to the air filter, could it be pulling in hot air making it run like that, I could see a little bit loss of power, but not this extream. The motorhome will barely do 55 on the highway floored. WHen it is running good it will do 70 without a problem at half throttle.

In '83, the snorkel didn't come from factory on the vans. I installed one on one and saw no noticeable difference, so this isn't your problem.

You're right, the engine isn't running right due to loss of power there.



One other thing, there are 2 little hoses that connect under the air filter they have a 90 degree angle and go on each side of the motor. When I bought it the one was cracked, I tried to find a new one but couldn't so I taped it up with electricle tape. What are these and how important are they, they could be collapsing from heat, would this cause it?

The little hoses are for the CDR system, which is part of the emissions on the engine to burn crankcase gasses (blow-by). These should be replaced, because they can be a source of dirt to get into the engine.

So..

You've got a fresh air filter?

Fresh fuel filter(s) - 83 will have two, one underneath and one on the back of the engine underneath the air filter on the back of the engine (will be square).

Check the air resonator that connects to the air cleaner. Some have been known to collapse at the connectors, leading to no-air.

lastly, I do believe that this can be a failing injection pump. An 83 Gvan I work on occasionally does this as well, with the same report. Usually getting off the accelerator and then back in clears it up (an intermittant thing). I have also had other engines do similar things only to clear up later. I suspect the injection pump itself, but do no know what exactly is the cause internally inside the critter.

That's all for now :D

[christrucker]

Is there anything you can do to the injector pump to make it work, like clean it, tap on it with a hammer?? Or just get a new one.

another thing is it seems to have less power the harder I push down the gas. You can almost feel where the engine starts to bog. So the black smoke and no power is symptons of the IP?? Thanks.



-Chris-

[john8662]

The injection pump is at the bottom of the troubleshooting chart, consider it only after you've narrowed everything else out.

It's a replacement kind of thing, a rebuilder can likely rebuild what you have or do an exhange.

J