# 1989 Ford 6610 missing on startup



## Wayne Locke (Dec 1, 2019)

I have a 1989 Ford 6610. The longer it sits not running the harder it is to start. Even if it sits over night it seems to be missing on one cylinder with gray smoke for a few minutes on start up. After that few minutes it runs ok with almost no smoke. It uses very little oil. Most of that is from some blow by and the main seal is leaking some. I would be thankful for any advice on where to start troubleshooting this problem.


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## SidecarFlip (Mar 25, 2021)

Check your injectors. Time to bench them for spray pattern and pop off pressure.,


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## Wayne Locke (Dec 1, 2019)

SidecarFlip said:


> Check your injectors. Time to bench them for spray pattern and pop off pressure.,


Thanks. So one or more of the injectors could be weeping off into the cylinder after shutoff?


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## SidecarFlip (Mar 25, 2021)

Injectors are mechanical and I have to presume you have a lot of hours on the engine and between the hours and the ULSD fuel you now use, the injector pintles are probably shot.. Time for new ones or get them rebuilt. Mechanical stuff wears out and your tractor is old.


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## Wayne Locke (Dec 1, 2019)

SidecarFlip said:


> Injectors are mechanical and I have to presume you have a lot of hours on the engine and between the hours and the ULSD fuel you now use, the injector pintles are probably shot.. Time for new ones or get them rebuilt. Mechanical stuff wears out and your tractor is old.


Thanks for your help! I bought the tractor two years ago from the second owner. So I have no idea when or if the injectors have ever been rebuilt or replaced. I have injectors ordered. Will let you know if this fixes the problem.


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## Wayne Locke (Dec 1, 2019)

Well after $330 and a lot of work getting one stuck injector out, new injectors didn't fix the problem. After installing the new injectors, I ran it until it was good and hot. let it sit over night. On cold crank next day got the same smoking as before. Could it be oil leaking from the head down into the cylinder ?


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## Hacke (Feb 22, 2011)

Does it have a Thermostart cold starting aid (flame heater in the intake)?
If so, look into the intake manifold for leaked diesel after it has been sitting.

*** Edit
I think I have the correct diagram (09F03) attached.

Better than just looking, disconnect the tube #10 from the heater #11, plug the tube and leave it like that. If it can not be plugged easily, put a hose on it and lead the hose to the tank filler hole.

Run the engine until it stops smoking. See if the problem is gone at starts after sitting over night.
And, of course, heating with Thermostart will be disabled during this test.
***


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## Wayne Locke (Dec 1, 2019)

Hacke said:


> Does it have a Thermostart cold starting aid (flame heater in the intake)?
> If so, look into the intake manifold for leaked diesel after it has been sitting.
> 
> *** Edit
> ...



Hacke, thats the first time thats been mentioned to me or mentioned in any website or forum of all my other research on this issue. I'm hopeful you are on to something here. Its piped like the diagram you attached. There is the heater in the intake manifold. It heats when the start key is held to near the two oclock position And it does work. I've tried that. Don't need it in central Georgia. The tubing is piped back to the top of the injector pump. I thought that was strange from the first time I saw it. An air intake heater with a fuel line piped to the injector pump??? First Ford tractor I've owned. Possibly the last too. Anyway, so how is this supposed to work? Heating diesel fuel weeped into the air intake manifold? What controls when and how much fuel enters via the heat plug? I know I've asked a lot of questions here but I just want to learn this tractor since I'd like to keep it for a while. I'll find a way to plug it at both ends since I will never need it here in central Georgia. Then I'll run it until hot and do a cold start the next day. Thanks for your help ! ! !


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## Hacke (Feb 22, 2011)

I attach a picture with the function explained and a link to a video that shows the flames in action (turn down the volume first, there is a terrible noise at the beginning).

The heating coil vaporizes the fuel before ignition. Liquid diesel is not meant to come into the manifold, but if the valve is not closing properly, it may happen. If so, it stays open at all times. If it is a smaller leak, you may get the problem you have. It is not enough to show when the engine runs normally, but after a night standing it has leaked so much that you will have the symptoms.

It is a theory, that's all, and it does not harm to test it.


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## Wayne Locke (Dec 1, 2019)

Hacke said:


> I attach a picture with the function explained and a link to a video that shows the flames in action (turn down the volume first, there is a terrible noise at the beginning).
> 
> The heating coil vaporizes the fuel before ignition. Liquid diesel is not meant to come into the manifold, but if the valve is not closing properly, it may happen. If so, it stays open at all times. If it is a smaller leak, you may get the problem you have. It is not enough to show when the engine runs normally, but after a night standing it has leaked so much that you will have the symptoms.
> 
> ...



Hacke, as as instrument and controls technician in a pulp mill for 39 years and being raised on both my Mother's and Father's families farms, I have a good understanding now, thanks to you, how this intake heater works. I can see how this is definitely a possible cause of my problem. I will let you know what I find. Thanks Harke and thanks to all of you that have helped me with this problem.


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## Wayne Locke (Dec 1, 2019)

One more thing I should have mentioned earlier, it does seem to lose fuel pressure on the manual lift pump depressor while sitting idle. Another reason I thought one of the injectors was leaking but then I thought, WTH, any significant amount of fuel would have to leak through the injector pump. Which seems unlikely since it runs good after heating up. Now I'm thinking/hoping Hacke has hit the nail on the head. I hope so anyway. I'm getting frustrated here.


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## Hacke (Feb 22, 2011)

The hand pump is there to fill new filter(s) with fuel. Are you pumping by hand before starting the engine? Not needed.

*** Edit
I see now that they changed to a rotary pump instead of the inline pump. If you have a rotary pump, disregard the comment about the cold start button.
***
Do you engage the cold start button as well? Not needed at temperatures over -4° C, or 25° F.


These actions give you excess fuel at the start and can be (part of) your problem.


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## Wayne Locke (Dec 1, 2019)

I plugged the port at the injector pump that goes to the cold start glow plug. Ran the engine until all the exhaust smoke cleared then contnued to run it until it was up to opereating temperature. Let it sit over night. When I cold started it the next day the smoking was not any better. No I don't pump the manual lift pump before starting, I just noticed that one time that it was easier to press after running tractor for a while. Just as a troubleshooting step. No I don't use the cold start. I also left the cold start glow plug unwired when I plugged the fuel port.


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## Wayne Locke (Dec 1, 2019)

Anymore troubleshooting suggestions would be greatly appreciated. Thanks to all of you for your help so far.


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## thepumpguysc (Jan 25, 2015)

It’s sounding more and more like an engine problem..
Thermostart deactivated- no change.
New injectors- no change.
The injection pump is a rotary type which means, only 1 pumping unit for all cylinders..
For a 40 year old machine u should be happy it starts at all. Lol


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## Fedup (Feb 25, 2014)

"Sounding more and more like an engine problem."

That was my feeling from the first post, the key being the line concerning oil consumption "most of that is from some blow by" So now we have fresh injectors, which is always a good thing, but the lack of improvement pretty much eliminates that as the root cause of the complaint. The thermostart? Yes they do fail. Usually the element burns out, but sometimes the fuel leak issue does come up. It will more likely be noticed while running, not just a few seconds on startup and only one one cylinder. 

My guess was a slight loss of compression on one cylinder, possibly some minor ring/piston wear or damage that only affects performance on initial startup, and fades away as the piston temperature rises. Might take a bit longer on a cold morning, but it's not uncommon in older tractors or any diesel engine for that matter. Is it a cause for concern? Not really. Is it worth the effort and cost of correcting? Probably not unless it gets a lot worse very quickly. There are plenty of tractors out there with similar situations, and they get on just fine. 

Just my take on it.


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## Hacke (Feb 22, 2011)

Fedup said:


> ...The thermostart? Yes they do fail. Usually the element burns out, but sometimes the fuel leak issue does come up. It will more likely be noticed while running, not just a few seconds on startup and only one one cylinder....


A minute fuel leak from the Thermostart will not show when the engine is running. Drops will be mixed with air and distributed to each cylinder in small portions. Over night the drops will accumulate under the heater plug and run into #1 cylinder's manifold tube. When the engine is started, fuel will get into #1 cylinder through the intake valve, and the engine smokes. After a while, the fuel is consumed and the smoke disappears.

That was my idea of a possible scenario.


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## Hacke (Feb 22, 2011)

Wayne Locke said:


> Anymore troubleshooting suggestions would be greatly appreciated. Thanks to all of you for your help so far.


Get ready with tools to remove the injectors, and a compression tester.
Run the engine hot.
Remove the injectors and test compression on all cylinders.
Let the engine cool down over night and redo the compression test.


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## Wayne Locke (Dec 1, 2019)

How much does a compression tester cost?


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## Wayne Locke (Dec 1, 2019)

The blow by gets worse as the engine gets to operating temperature not better. Does that rule out excessive ring/piston wear on one or more cylinders that gets better as the engine heats up? Could it be the leak off lines not draining to the fuel tank? I replaced the brittle leak off lines a few months ago because one was leaking. Are all four banjo bolts the same? I removed them when I replaced the lines and replaced the copper seals because one was leaking. I think I did them one at a time so not to mix them up but can't remember for certain. The leak off line at the front is piped back to the injector pump. What is that for? 

I bought this tractor about 18 months ago. Here is the history on this tractor since I bought it. To the best of my recollection. Which isn't great anymore. This list is not necessarily in chronological order. And yes, some of the items are definitely not related to my current issue.

1989 year model with about 3800 hours. Per the hour meter anyway.
There was almost no smoking on cold startup and none there after except when accelerating or under short period heavy loading. What I would call normal.
There was very little blow by.
Changed engine oil and filter.
Drained, flushed and refilled with new coolant.
Installed thermostat since there was not one in there at all. So engine running higher but normal temperature. This may have been a mistake as I look back on it.
Replaced muffler since it was bent at inlet pipe, had been brazed but still had small leak.
Replaced radiator because it was leaking.
Replaced radiator hoses
Replaced fan belt
Replaced inner and outer air filters.
Replaced injector leak off lines.
Replaced injector banjo bolts copper seals.
Replaced injectors
Unwired and unpiped intake manifold glow plug.
Replaced power steering cylinder.
Replaced all four steering ball joints.
Removed remote hydraulics because the connectors were leaking. Plugged at the lift cover.


Added some Lucas oil treatment when the blow by started getting worse
Started adding Diesel Kleen + Cetane boost.
I believe the smoking on cold startup started around the time I replaced the leak off lines and banjo bolts seals. Not certain. May not be related to my issue.
Yes I know, I should have kept notes with dates. Especially since my memory is not so good as I get older.

Thanks again for all your help!


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