6.9 sudden NO power and smoking

[hayman68]

We've had this old truck on the farm since new. Was my fathers and hasn't been used much the last 20 years only has 102,000 miles. Lent it to my brother for a few weeks as he needed a vehicle. Said one day at work he started it and it idled real rough, smoked terrible and low power. I told him to park it and now I got it in the shop checking it out.

It has a turbo on it too my dad had put on in the 80's. Checked basics and took for a spin no visible leaks. It has NO power barely makes it to 30-40 mph. Smokes REALLY bad. Air filter was dirty replaced it, checked turbo its spinning, exhaust is ok ( needs new exhaust) . All original injectors and injection pump. I was gonna replace the fuel filter next here but got to thinking the way its smoking (over fueling) its getting fuel. I took an infrared thermometer and checked exhaust ports after I took it for a spin. They all seem pretty equal like no dead cylinder.

Do these injection pumps fail like this ? Something gets stuck in them?? Called diesel shop that originally put the turbo on that's still in business but the guy there had no idea said it was too old and they don't see these trucks anymore and no longer rebuild the pumps due no parts. Said to check with the parts department and see what they can do. Anyone seen this issue ??

 

[FrozenMerc]

If it is heavy black smoke that you are describing, you are either getting too much fuel (broken injector tip for example) or too little air. I would lean towards the too little air side of things and start looking for a restriction. Mouse nest in the air filter box for example.

The injection pump will fail via under fueling. The pump piston bores wear out, clearances open up, and the pump can no longer force the fuel down the lines to the injectors. It just bypasses into the case.

 

[Rdnck84_03]

First important question is what color is the smoke?

James

 

[hayman68]

It smokes white/blue. Has no air restrictions.

 

[Rdnck84_03]

Does it smell like unburnt diesel or sweet like coolant.

 

[hayman68]

Does it smell like unburnt diesel or sweet like coolant.

Doesn't have coolant smell. Going to do more checks tomorrow.

 

[rhkcommander]

White n blue without coolant smell usually means it ain't burning the fuel. Time for a compression test...

 

[Rdnck84_03]

If you don't have the stuff to do a compression test already, I would try a few more things before going and buying it.

Does it smoke at an idle also or just at higher rpm? If only at higher rpm, does it do it while just holding the throttle an higher rpm or only under a load?

If it were me I would start with a new fuel filter, fill it with atf or diesel treatment. Start the truck and let it run for about 45 seconds, shut it off and let it sit for 12 or more hours to break up anything that may be in the pump and injectors.

After which fire it up and take it for a little drive and drive it like you stole it, if you don't notice any improvement in the power or smoke after a bit of flogging it then I would move on to other testing.

James

 

[hayman68]

If you don't have the stuff to do a compression test already, I would try a few more things before going and buying it.

Does it smoke at an idle also or just at higher rpm? If only at higher rpm, does it do it while just holding the throttle an higher rpm or only under a load?

If it were me I would start with a new fuel filter, fill it with atf or diesel treatment. Start the truck and let it run for about 45 seconds, shut it off and let it sit for 12 or more hours to break up anything that may be in the pump and injectors.

After which fire it up and take it for a little drive and drive it like you stole it, if you don't notice any improvement in the power or smoke after a bit of flogging it then I would move on to other testing.

James

Yesterday i found that I had a fuel filter on the shelf. Put it on and no difference. Cut the old one open and all looked okay inside wasn't plugged just normal sediment etc. General engine Compression I can't see going south suddenly unless a valve went bad. As mention seems all cylinders are firing evenly. Going to do more checks today. My brother did dump in some sort of injector cleaner back when it happened.

 

[FrozenMerc]

Does it start smoking right away, or after things warm up? I am thinking of a possible bad oil seal on the turbine side of the turbo. Putting oil into the exhaust stream that is burning off causing the smoke. Turbine is coked up and not generating enough / any air flow on the compressor side, and hence the low power.

 

[hayman68]

Ppulled

Does it start smoking right away, or after things warm up? I am thinking of a possible bad oil seal on the turbine side of the turbo. Putting oil into the exhaust stream that is burning off causing the smoke. Turbine is coked up and not generating enough / any air flow on the compressor side, and hence the low power.

Pulled off the check valve/regulator on top of the pump. It's not functioning correctly it seems. If pressure builds up in in pump housing things don't work correctly from what I've read. There wasnt like sediment or stuff stuck in there but a film of gunk or something on the glass ball. Carb cleaner helped some. The ball doesn't move. Soaking it more.

 

[hayman68]

Well its back working again as normal. It was the check valve all stuck.

I put the valve in the ultra sonic cleaner in varsal from 20 minutes. That loosened the ball and spring up. The spring was packed with like a varnish stuff. It didn't look rust or metal sediment. See pic. I was able to pick and blow the stuff out of the spring down in the bore of the check valve. Now the ball moves correctly. Thanks for the tips.

 

[Nero]

Shame you went through the haste of changing the whole pump just for it to be something so simple!

 

[IDIBRONCO]

General engine Compression I can't see going south suddenly unless a valve went bad.

You're right and you'd know if that happened. While a compression test is good in some situations, it's about the last test that I'd do to one of my trucks. I just don't feel that it's really that important and not necessarily all that accurate in diagnosing a problem such as you were having.

As mention seems all cylinders are firing evenly.

Which is why it wouldn't be a valve. Not to mention that your used a non contact thermometer on the exhaust manifolds and all cylinders were close to the same temperatures.

Well its back working again as normal. It was the check valve all stuck.

That's good to hear. I know that my above answers were a little late, but I wanted to give them anyway.

 

[Brian VT]

Well its back working again as normal. It was the check valve all stuck.

I put the valve in the ultra sonic cleaner in varsal from 20 minutes. That loosened the ball and spring up. The spring was packed with like a varnish stuff. It didn't look rust or metal sediment. See pic. I was able to pick and blow the stuff out of the spring down in the bore of the check valve. Now the ball moves correctly. Thanks for the tips.

Wow. Good work, detective!
For my future reference...where is this check valve? (a picture would be great)