JD 450C - Won't start after fuel system work

[DSK]

After replacement of an injector and parts of the lines, changing both engine fuel filter and tank filter, draining, cleaning and refilling the fuel tank, I've bled the system and have been cranking it over. At first it ran for maybe 30 sec then died. Running time lessened with each attempt after. Now, it will not start.

I'm cranking no longer than 5 sec each attempt, to try to not be so hard on the starter motor. Probably more like 3 sec. I'm giving it some time between attempts as well.
I first used the priming lever to get fuel up to the filter then pump, then I did see fuel at the injectors while cranking and tightened the connections.
I'm getting starkly white smoke out the exhaust, more than at the start of testing.

I do have a stripped out return line nut (the one the fuel line grommet goes in) so I know I'll need one of them, but a return fuel leak shouldn't be causing this, correct?
Earlier, I tried cranking with the fuel cap off (I'd heard of this before somewhere); it did not start that time but did after a few more tries. But now nothing.
I did use vinegar in the tank for cleaning, so it's possible some got into the pump. It couldn't have been much because I had the filter off while priming up to it, then disconnected the pump line completely to prime to the pump.

Is there a way to rule out the injector pump as being a problem here?
What else should I be looking for.

This has been wordy...if anyone has made it this far, some ideas/advice would be so helpful. I've spent a lot of money and time on this and it's very disappointing...
Thanks

[Jim B]

I would try cracking the injector lines from the pump loose at the injectors again. it may have moved air into them as the system bled out.

Is the battery still cranking it good? You may need to give it a boost to keep it spinning fast.

[DSK]

Thanks Jim,
I'm recharging batteries for another go.
I will rebleed; I'll need to anyway since I've disconnected the injectors again, after noticing some fine particulate rusty fuel coming out of the return line at the injector. I'm starting to think I may not have been thorough in cleaning the last bit of fuel line leading up to or at the pump. It looks clean at the engine filter and directly out of the pump, but may be dirty downstream... I wonder how much trash it takes to clog an injector...maybe that would explain my running ok at first, then worse with time. Can injectors be cleaned?

[DSK]

Same problem with new (cheap) injectors and charged batteries. It starts off running fine but dies shortly. Every attempt to start after this, it starts and runs for a shorter time. The longer it sets the longer it will run, but no more than 10 seconds total. Any attempt to increase rpms and it dies quickly.

Before putting injectors in, I watched all fuel lines shoot fuel so I know there's fuel getting to them. There's about 10g in the tank.

If it's the injector pump, why would it run fine for a short time then fail? This is really starting to irritate me...any ideas for my next steps?

[Jim B]

If the flex ring is breaking up, the bits from it can plug the return from the pump and once there is a certain pressure inside the pump it will quit. The bits generally plug the check valve where the pump return line connects. Some people break the check assembly out and keep running. Not the best idea as it fixes nothing, just lets things get worse from continued operation. The engines will restart after setting a while, as you describe. Put a clean white rag below the timing cover plate on the side of the injection pump and carefully remove the plate. See if there are any bits in there that look like mouse turds. If so, that is a sign the ring is breaking up and an overhaul of the pump is in order. You can also try loosening the screws in the plate and let it leak a bit. If it will stay running with the plate leaking, that is another sign the pump needs an overhaul. A pump shop should install the newer style weight ring and do away with that flex ring, if that is what you find.

Search pellethane ring on this site and you will find a good number of threads/posts with similar symptoms to yours.

[DSK]

Thank you Jim.

I'll try loosing the timing cover plate and see if it runs.

I remember last winter I had opened that plate and saw at least 2 "mouse turds" in there with the fuel that drained out. When it still idled then, I thought I was ok, but now that the problem is worse perhaps it's time for a rebuild after all. I'll definitely check for those pieces again to confirm.

I'll line it up and get the pump off...this is going to be fun...
Thanks again.

[Jim B]

Do you have a pump shop near you to use? Some people trying to do this themselves. Some succeed, some end up costing more in the end when they take it to a shop after they tried and broke something. I recommend a true injection pump shop that has the equipment to test and calibrate the pump after they rebuild it.

You or the shop need to be sure the check valve is clear and working when the pump work is done.

You may be aware of all this; I'm throwing it out for the benefit of another encountering the same issues in the future.

[The Jug]

I went through that also. Was about 1 k rebuilt with no parts broken then I came across an online shop you send pump to, and they will rebuild it for 500 I wish i saw that first of course.

[DSK]

Jim, I did get a local quote for rebuilding the pump several months ago and it was over $1k, if I'm remembering right. That was when I started wondering how difficult can this be...
But I agree with your point completely.

Jug, I would like the info for this online rebuild option if you have it. With parts I'd be halfway to that cost anyhow. I really don't have the time to try to do it and would absolutely prefer someone else who knows the innards of these things. One of my initial concerns was being unable to test it once I got done fiddling with it.

[Jim B]

Sent you a PM.

[DSK]

Received, thanks.

[Stan Disbrow]

Hi,

Another, often overlooked, item is the fuel tank vent. Bugs like to plug that tube. It then tends to pull a vacuum and stall out the lift pump. An easy check for that is open the fuel cap right after it quits. If you hear air flow as the cap gasket releases, you have to clear out the vent tube.

Here is a thread from over in the FAQ about the vent tube. It's a 350 tank, but the same applies to the 450 ones. At least the earlier sub letter ones.

viewtopic.php?f=2&t=13107

I'm leaning towards Mouse Turds in this particular case, but sometimes it is the vent tube. Especially after the tank is fully filled up to ease the work on the rest of the fuel system. No extra space in the tank and the vacuum forms fairly quickly as a result.

Stan

[DSK]

About to close this one out. Thank you Jim and Stan for your inputs.
Yes, I had checked out the tank vent line initially, had to dig it out with wire at the bottom end and blast with air.

Regarding the subject line problem, yes (surprise) it appears the fuel injection pump was in need of a rebuild which is why I couldn't idle. I loosened the timing cover (thank you Jim) and drove it up the hill to where it was much easier to work on and on level ground. Rebuild costs ranged from $450 to over $1500. I called about 8 places across several states.

In the end (not to spurn advice...) I ended up paying for an online DB/DC pump manual, bought the parts kit and...put in the kit myself. I bought everything from a place in WI called Badger Diesel for just under $200. My reasoning was with everything else being so old and mistreated on this dozer, paying the extra money may not have been worth it overall. I heard from the place I bought the kit from that these pumps have had problems with DIY repairs where the pump will literally explode after about 10 hrs if it was not reassembled correctly. Not sure if true. I'm at about 8 hrs runtime thus far so we'll see... 10 hrs seems oddly specific.

Concerning lining up the engine, for the life of me I could not see the other timing mark on the weight cage side. I don't believe it was there. When I got it apart I looked for it carefully but could not find. It was helpful to recall the crankshaft pulley mark, which then was confirmed by the flywheel hole but it took a lot of fiddling.

The teardown and reassembly wasn't bad, cleaning everything took forever. The internals were profoundly rusty. I took it to work and fiddled with it during downtimes.
The reason I didn't see many pellets/turds in the fuel was because that flex ring was gone save one tiny place. What a sight.
Worst part by far was getting the Bristol fastener on the cam ring to break loose...spray lube, heat, hammers, etc. Broke the $35 B wrench but got it off eventually. Pilot tube and cam ring looked ok.
The famous umbrella seals went on with some grease and no trouble.

I hope no one thinks I wanted to willfully disregard the advice to have it rebuilt and tested. When weighing costs versus what I needed it for and the general state of the machine, it just made more sense (I think). I still agree I would rather have had it tested for the peace of mind...now I never know whether the pump will "explode" any second.

If anyone made it this far and hasn't perished of boredom..separate question while I'm here..
I have no tachometer and really want it working. I traced the cable into the engine and pulled out a cylinder gear which the cable went into. There is nothing else to be seen in that hole that can meet and turn that gear; the hole is empty.
What should be on the other side of the tach cable gear to turn it? Looked at parts diags but can't locate. Seems like I may be sunk on that one. Maybe there is a broken piece down in the crankcase somewhere.

Grateful for the forum. Thanks for the advice and knowledge.

[LeonardL]

So that cam pin that requires the Bristol wrench can be a pain but they are a shock release to get them out. I opted long ago to spring for a snap on socket and a short breaker bar. Then a good hammer to shock those loose.

You may be screwed as far as the tach I'm afraid. If that was a worm gear that came out then you're done. If it was an insert that the cable fits inside of then you may still be okay. It's been too many years since I was last inside one to remember exactly how they assemble. You may need to go talk to the Deere guys and see if they can help you sort this out.