JD350 crawler/loader severe power loss..bogging under load

HI guys,

I am going through my just arrived 1968 JD350 crawler loader, looking after all the neglected maintenance items collected over the years, and am now working on restoring normal power to the machine.

When she's cold, she smokes grey, and as it warms up, smoke turns blue, then after working the machine for 10 minutes, the smoke all goes away. In those first 10 minutes though, it's a gutless wonder, at almost full throttle, just opening the clam shell almost stalls it. Putting it in 3rd and rolling away same thing. Smoke also changes color as the load changes, from grey to greyish blue. After it thoroughly warms up, it seems okay, although not as snappy as my other first gen 350. It almost seems like the governor is stuck, it comes up to speed very slowly after a load is applied, sometimes never comes back to full speed.

Things I have checked so far.

1. Air intake system...filter was rusted, plugged and disgusting. Removed that and cleaned everything. No difference.
2. Tank drained and all fresh fuel.
3. Checked fuel supply to the IP, pumps like crazy at the input to the IP just cranking the engine.
4. Checked output fuel flow from the IP while running, flows clean. Removed top cover of IP looking for mouse turds, none found, clean.


When I refilled the tank, I added about a cup of ATF to help clean things up, also put a little in the crankcase. I haven't checked the timing. The IP looks like it has been serviced at some point in its' life. It comes up nice and clean with just a blow nozzle. Fresh safety wires.

The machine has sat for the last 3 years with no movement. The fellow started it once in a while but never drove it around.

I have run it around for about an hour or so in the last few days with no real change.

What else should/could I be looking at?

Your thoughts?

Thanks!

Here is a video I made of the machine just opening the clam shell....

http://www3.telus.net/radioboy/JD350 smoke.mpg

One other thing I noticed...when it is idling, and it's all quiet, I can hear something metallic rattly sound coming from the IP. I can hear it just standing next to the machine, then when using my pry bar stethoscope, I can hear it near the bottom of the IP. I'm guessing after all of my research on the DBG IP pump on my other 350, that the retainer ring [i:2c502e4e21]may[/i:2c502e4e21] be completely gone???

Anyway, look forward to some help before getting out the wrenches.

Cheers

Okay, quick update...

So I went out every 1/2 hour for the last 4 hours and ran her up and each time, after about 1 minute of good full throttle up/down with the bucket, she would smoke for the first while, then after a while would start popping, puffing (guessing white) smoke (as it was dark) and would all of a sudden clear up after about 4 or 5 good pops, and then run fine, full power with no smoke and lots of power, no loading up and slowing down. Every time I let it cool for half hour, it would go thru the same cycle, and with the same results. Pop a few times and clear up to be normal. In my layman's experience, this sounds like and injector sticking and warming up and clearing, not an IP issue. Second thought..valves??

Again, look forward to the more experienced people chiming in.

Thank you.

Sounds like you might have a combination of few
broken piston rings and a injection pump that
needs work. Was someone using ether on this
machine in the recent past? 350 break top piston
rings REAL easy when hit with too much ether.
When they break, they still run almost "OK" when
warmed up but otherwise, terrible. But since the
pump likely has to be fixed anyway, might as well
fix that first and see how much improvement you
get.

Okay John, Thank you.

If I understand the IP correctly, I should be able to remove the timing window cover, and see if the Pellathane retainer is still in there, visible as a thin black ring next to the weight retainer. If not, that confirms it's disintegrated and pump needs to come out. If it is still there, sounds like it might be something else inside the IP??

I'll order 2 seal kits and pilot tubes and a few other things you have mentioned in other posts, that seem to be common wear items in these pumps. I now have two 350s with these IPs that need work.

Thank you!

Paul

PS ether, yes a few spritz's in the morning to get her going for the day, no long, saturating shots as far as I know.

Okay, another update..and some more symptoms.

Checked the static timing, was off maybe 2 line widths, not bad, I corrected that and tried to see the retainer ring. Fit was too tight to see it, but I put a small stainless wire in between and felt like it was dragging on rubberish material.

Gave it a good 20 minute run up/down the driveway, ran like crap for the first 10 minutes, lacked power, would barely go up my not very steep driveway, barely in second gear. Operated the clam shell at the same time and that could have stalled the engine if I let it. Stopped, let the engine speed recover then carry on up the driveway. Did this about 8 times, then on the next trip up, she started backfiring, and popping, some good pops, each one with a little flame burst from the short stack (hood off) then like someone turned on a fuel supply to another injector...she started to really come on, loads of power, smoke completely stopped, smoothed right out, just like someone hit a switch. Wish I could have recorded it, it was an amazing transformation. Couldn't stall it no matter what, loads of snort. Ran it up and down for another 10 minutes and it ran perfect the whole time. Then I let it rest at idle for a minute....decided to run it a few more times and all of a sudden it started backfiring again when I throttled up and loaded it, this time it cleared up in about 30 seconds. Tried the same thing multiple times and each time the same, off idle, go to full throttle, then she'd fart and pop, then clear up under load after about 30 seconds. And after it clears, when she is running, it's smooth and clear and no smoke, loads of power

Anyway, I don't know a ton about these, I'm learning, but to me, it seems like a sticky injector, or something hanging up inside the IP, like weights or ??? and affecting the timing. I don't know how an off time engine sounds. Could a sticky valve cause this? Is this a flaky injector symptom? This machine sat for 3 years without any exercise. Could the IP be loosing fuel pressure at idle then slowly come back up? Or weights relax then slowly come back to correct timing? I don't think it is heat related now.

Here is recording I made of it going up/down the driveway, opening/closing the clam shell. At about 50 seconds, you can hear it starting to pop, then at about 2:30, it clears up.

http://www3.telus.net/radioboy/running up driveway.mp3

Thanks in advance for any input.

Cheers

Progress...finally.

Started it again this morning, this time with a paint stripper gun down the intake pipe instead of ether..fired right up.

Warmed it up as usual, still no power, and smoking, got it up to temp then got out my IR heat probe and measure each cylinder temp at the exhaust manifold port, about halfway up each runner. So here we go... #1 and #3, both 250-260F, #2 is 180. Ahh hahh!
Cracked the #2 injector line and fuel is spritzing out, engine slows slightly and the exhaust smoke goes away. Mmmmm? :?: Now, could this be a stuck open or closed injector or like mentioned, rings?? How could rings work one minute, but then not work the next? As mentioned above, after some good hard running and a few backfires, it clears up and has full power and no smoke.

So, I think my next course of action is to pull the injectors and do a compression test, and then depending on the results, put in new injectors. I just happen to have 3 new ones waiting to go in my other 350 dozer.

Anyway, that's the update from the front.

Cheers

Another update...3pm west coast time..

I removed all of the injectors, # was pretty carboned up on the tip so I used that as the sacrificial lamb, ground off the tip and built a compression tester. By the time I got all of this done, the engine was cool but here is the data.
#1 - 150 PSI
#2 - 50 PSI
#3 - 150 PSI

added oil to # 2 and it came up to 65 PSI.

So, with all this info now, and the only place for the backfiring flame front to come from is the exhaust valve, I'm thinking valves on #2. Going back out to pull the valve cover and see what clearance we have.

Look forward to any input from the Diesel experts.

Thanks!

Hi,
I would first check the copper banjo fitting washers on the fuel line in on the injector pump.
I had the same problem with my machine
cheers

Yes, checked all of those copper washers when I put in the new injectors, they were all good and seal well.

Checked the valve clearances and all were pretty much right on.

I put in all new injectors, no difference. I will order the pump seal kits and see if there is a problem with the IP. In the meantime, I wonder if it's worth warming it all up, getting it running right, then pulling out #2 injector and measure it hot to see what the compression is?

Thanks guys.