D6 9U Fuel Issues

[Diver1]

Good Evening Folks,

Just signed up with the forum, first post. Full transparency, I am not a diesel mechanic and I didn't stay in a Holiday Inn last night. I purchased an old Caterpillar D6 9U dozer a few months ago and have been tinkering on it when time permits.
I'll try to list my efforts and results to date:

1. After pressure washing the engine to see what color it might be, yellow not dirt brown, I found a few things that I didn't see before my purchase.
2. The Cat ran weak and lacked power as I drove it into my back yard and pushed some dirt and rock in my rock pit. The exhaust was lightly smokey until putting under load and then it seemed to get less smokey and lost RPM. I only operated it for about twenty minutes.
3. I parked it where it would be easy to work on and pulled the pony motor, it was in pretty bad shape. I purchased an electric starter and single wire alternator conversion from Auto Lec Re-builders and installed it after boring, drilling and tapping threads. Works good.
4. Fabricated a battery box to fit where the pony motor used to be, works fine.
5. Pumped the crankcase oil out and replaced it. Replaced the oil filters too.
6. Cleaned the dead rat, dirt and bugs out of the air cleaner and replaced the oil.
7. Opened the fuel filter tower and removed the filters, this is where it got ugly. The filter tower was 3/4 full of fine rust, about the consistency of frosting.
8. I cleaned everything thoroughly and drilled and tapped the filter housing for a 0-30 PSI oil filled pressure gauge and installed it. Installed new filters and put the top back on. Opened the air bleed vent and the 1/4 turn fuel valve and waited until I got fuel instead of air, then closed the bleed vent.
9. I rolled the engine over intermittently with the de-compressor lever in the start position to build oil pressure and check the fuel pressure. There was no fuel pressure registering, the needle may have moved slightly but that's all.
10. I pulled the fuel transfer pump and disassembled it. The square seal had been pinched badly by whomever was in there last. Put a new seal over the ferrule and reassembled the pump and installed it.
11. The by-pass assembly was missing the plunger so I turned one out of Torlon plastic on my lathe and then installed it.
12. Rolled the engine over again and got 7 - 10 PSI on the gauge.
13. Tried to start the engine and it coughed a few times with ether but did not start.
14. Cracked the nut on #1 - 6 lift pump and saw weak fuel pulses after bleeding the air out.
15. Cracked the nut on the injector line #1 - 6 cylinders and bled the air out.
16. Tried to start the engine and still no luck.
17. Removed and replaced the three very weak lift pumps with used purchased from eBay.
18. Checked and adjusted the injection pump lifters # 1 - 6. Here is where I may have gotten off the reservation; I do not have a depth micrometer so I used a very small T- square and adjusted it to my digital calipers. This may not be accurate enough so I have ordered a digital depth micrometer, should be here in a day or two.
19. When opening the inspection port for the flywheel pointer I noticed a fair amount of debris and oil soaked fibers clinging to the pointer. It looks like there have been some real bad clutch issues in the past, lots of welding on the bell housing and a piece the size of a golf ball missing. I am wondering if the pointer has been dislodged from it's proper place a little?
20. Cleaned all of the fuel injection valves, still won't start.

Tomorrow I will build a fixture to test the nozzle spray outside of the head.

Ideas are most welcome!

Ken

 

[Cliffy]

Do you remember what colour the smoke was?
I think that will give us a big hint into what direction to head to.
I believe the pony motors are great design. Frees everything up, builds oil and fuel pressure and puts heat into engine. They can also mask underlying issues with lack of compression in cylinders.

 

[Diver1]

It was black smoke but not heavy as you would expect with dirty fuel.

The pony motor was truly a mess and barely ran at all. I didn't see the sense in rebuilding it and a preliminary search revealed that parts were going to be hard to find. If you are anywhere near southern Oregon and ,want it it's yours for free!

 

[Old Magnet]

What's the s/n, sounds like an early dry clutch manual that previously lost its drive links (dry fiber)
Have you checked the actual rack travel, not just the throttle position.

 

[Diver1]

S/N - 9U 6149
I have not checked the rack travel, but will get into my book this evening and read up on the procedure. I did pull the nozzles out of cylinders 4,5, and 6, because they are the easiest, and turned the engine over to check the spray pattern and only #3 was emitting fuel, and not spraying just dripping. Not sure what that means ...

 

[TomA]

Put the pony motor back

 

[Diver1]

I understand that a pony motor is useful in warming up the block and obtaining fuel and oil pressure. As I stated, the pony motor on this Cat was on it's last leg and would barely turn the engine long enough to start it, so it's not like it was doing it's job anyway.

Not sure how this would solve my fuel issues.

 

[Diver1]

I spoke with a local Cat mechanic today, he mentioned that during the installation of the lift pumps, if you happen to get one or more of the gear segments keyed into the rack wrong, even by one tooth, the governor may act wrong. My book is not real cleat on this subject. Where is the gear segment, which have a little brass ball pressed into the middle tooth supposed to be in relation toe the rack?

 

[Old Magnet]

Like so....

 

[Diver1]

Thank you Old Magnet. I do have that diagram in my book and installed all six gear segments in accordance with Fig. E. There is a chance I missed a tooth on one or more and will have a look today. While I am at it, I will re-measure the injection pump lifter dimensions with my newly purchased micrometer.

 

[Old Magnet]

After getting the segments checked get back to the injection capsules. I'd recommend you get new capsules for all.

 

[Diver1]

Late lunch break ...
The mechanic I spoke with said he could quickly bench check nozzles/capsules so, you are correct, I will pull all six and get them checked and/or replaced.

 

[56wrench]

Capsules are cheap. I would just replace them all

 

[Diver1]

Thank you 56wrench, that is probably what I will do, however, the mechanic I spoke with, and there aren't many around here, was so helpful that I thought I would bring a little business to him and establish a rapport.
I pulled all six lift pumps yesterday and found at least one gear segment was a tooth off in the rack. I say "at least one" because three of them came out of the lifter as I pulled the pump upward. I later discovered that with a mirror I could see the bottom of the gear segment and how it is indexed into the rack. I also discovered that the shaft of one gear segment had been ground on and was shorter than the tolerance in my book. I replaced it. I am still going to bleed air out of the fuel lines and attempt to start it today, can't get into the mechanic until Monday anyway ...

 

[Diver1]

Of course it didn't run yesterday. While I have all six capsules out, is there a good way to clean the cylinders out, carbon and such. I learned in high school shop class that trickling rice into the carburetor of a gas engine and feathering the throttle will clean out the carbon. It works like a champ too!