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perchance · 09-12-2011, 17:57

I'm out of hair to pull out so I'm throwing this open to any and all knowlageable diesel doctors.
The problem is over fueling of an Isuzu c240 with a kiki inline injector pump. The thing starts and idles like a champ and will rev to specified rpm but anything over idle and it lays down a smoke screen like a destroyer. In gear it will not exceed 1000 rpm. The injectors were pop tested so that ain't it. The pump was rebuilt and has no hours on it and when first installed it performed beautifully but the following day was when the touble started. I suspect something came adrift inside the pump but for the life of me I don't know what it could be.
Has anyone encountered this problem and if so what was the solution aside from the obvious "throw the effing thing overboard and get a new one"?

delmarrey · 09-12-2011, 18:20

First I would do a compression check. If that's all OK I'd take the pump and injectors back to where they were serviced. It sounds like the wrong pressure for the injectors.

Or the fuel is blowing by the injector seats (Were there new seals to go under the injectors? If so, they need to be crushed properly.)

Or an air intake restriction. Or timing.

Does it have a turbo?

Ironhorse74 · 09-12-2011, 18:24

First question what color is the smoke?

perchance · 09-12-2011, 18:26

No turbo, new seals, timing set by the shop. They are pintle injectors if that helps. The smoke is white and leaves a slick on the water.
Note: this problem appeared suddenly from being fine one day to shtf the next day.

bobconnie · 09-12-2011, 18:26

Sounds like the crush washers loosend up after cooling down from the first start up,or the pump sliped for the same reason ! ck this before returning the pump and injectors Bob and Connie

delmarrey · 09-12-2011, 18:32

Quote:

Originally Posted by bobconnie

Sounds like the crush washers loosend up after cooling down from the first start up,or the pump sliped for the same reason ! ck this before returning the pump and injectors Bob and Connie

Ditto! You're getting way too much fuel!

Belt drive or gear drive?? (w/o searching for a drawing).

perchance · 09-12-2011, 18:44

Gear drive and the marks are lined up as per the manual and the external timing mark is lined up exactly as it came from the shop. We tried advancing the timing but the engine didn't like it so we reset it to the original mark.

perchance · 09-12-2011, 19:09

Quote:

Originally Posted by Redcoat

When was the last time you looked at your prop.

I have yet to the see the prop but the boat lives in the Fraser river so barnacles are not an issue.

delmarrey · 09-12-2011, 19:11

I'd try reseating the injectors with new seals one more time. If that doesn't help then back to the shop they would go.

One more thing, check your dip stick to see if it's making oil (fuel in the oil). If so you could have a ring problem or a hole in a piston that suddenly showed up.

But not likely.

perchance · 09-12-2011, 19:20

Quote:

Originally Posted by delmarrey

I'd try reseating the injectors with new seals one more time. If that doesn't help then back to the shop they would go.

One more thing, check your dip stick to see if it's making oil (fuel in the oil). If so you could have a ring problem or a hole in a piston that suddenly showed up.

But not likely.

This was someting we suspected so we pulled the head and one piston to check ring condition and all is well on that end and there is no evidence of fuel in the lube oil so I thnik your suggestion of the crush rings will be the
simplest test. Failing that it is back to the shop for the pump.

**Ex-Calif** · 09-12-2011, 19:25

Quote:

Originally Posted by perchance

I'm out of hair to pull out so I'm throwing this open to any and all knowlageable diesel doctors.
The problem is over fueling of an Isuzu c240 with a kiki inline injector pump. The thing starts and idles like a champ and will rev to specified rpm but anything over idle and it lays down a smoke screen like a destroyer. In gear it will not exceed 1000 rpm. The injectors were pop tested so that ain't it. The pump was rebuilt and has no hours on it and when first installed it performed beautifully but the following day was when the touble started. I suspect something came adrift inside the pump but for the life of me I don't know what it could be.
Has anyone encountered this problem and if so what was the solution aside from the obvious "throw the effing thing overboard and get a new one"?

My grandma always said, "check out the last thing you screwed up, Danny"

- pump was rebuilt
- injectors were pop tested but apprently no rebuilt
- ran one day fine
- now runs with significant white smoke and low power

Symptom

- Too much fuel

Ideas
- injectors not reinstalled with new crush washers
- injectors installed with new crush washers but old ones not removed (ask me how I know this one - doh)
- injectors not torqued properly backed off
- pump failed. Not unheard of for an overhaul to go bad

Good luck

Horizon Watcher · 09-12-2011, 20:09

Hello Perchance

Don't give up on your C240 engine, they are a great long life engine.

I would bet on the problem being something in the injector pump was not secured properly, and has let the fuel rack go to the full open position instead of a regulated position.

If it was an injector problem, it would have malfunctioned on the first start up.

A good shop that did the pump overhaul would be glad to test it again on the bench.

Also, could there be any possibility of contaminated fuel.

I have this same Isuzu engine on my boat, and it is 31 years old, with all the original paint on the threads of the injectors and the pump. I do not know how many hours are on the engine, but it has worn out several mechanical tachometers.

Redcoat · 09-12-2011, 20:24

Have you left the dock since the repair? I mean on a test run? Is it posible that your prop is overgrown with muscles or extremely fouled.Kinda saw the same symptoms in Seattle. Would run fine in neutral and crap in gear.