Ford 5000 4 cyl diesel injector/pump help

[JF in MI]

I’m looking for help/suggestions in trying to figure out what is going on with a Ford 5000 4 cylinder diesel misfire. It has a frequent misfire on one of the cylinders until fully warmed up then runs perfectly smooth (this only started this year). Mostly at the higher end of the RPM scale but sometimes at cold idle also. One of the times it was missing at cold idle and I cracked the lines to the injectors one at a time and found the #1 injector made no RPM difference with the fuel leaking out. The other 3 almost stalled the engine when allowed to leak. I changed out the #1 injector for new and it seemed to be a bit better at cold low RPM but still missed at higher. Swapped out the #1 and #2 injectors but the cold low RPM miss stayed with the #1 cylinder when repeating the leaking fuel test. It has a Simms-Minimec injector pump. Has anyone experienced this? I’m wondering if the pump has an issue but, once again, when it reaches full operating temperature it runs beautiful.

 

[used red MN]

In my opinion it’s time to set the valve clearance and run a compression test to prove #1 cylinder is as capable of supporting combustion as the rest of them.

 

[JF in MI]

In my opinion it’s time to set the valve clearance and run a compression test to prove #1 cylinder is as capable of supporting combustion as the rest of them.

These were my thoughts exactly but as I mentioned I have very little experience in diesel engines and wouldn't even know how to do a compression test on an engine with no spark plug hole. To add to it; yes, it has a whole lot of blowby. Would it be common for low compression in a diesel to misfire while cold and that misfire clear up at full temperature? (makes sense to me but I don't know enough).

 

[used red MN]

wouldn't even know how to do a compression test on an engine with no spark plug hole

You pull the injectors and the compression tester has an adapter that takes the place of the injector or use glow plug holes which I don’t think your engine is equipped with.

Would it be common for low compression in a diesel to misfire while cold and that misfire clear up at full temperature?

Yes

 

[Dieseltech]

Runs fine warm, miss when cold is s sign of low compression. Pump is not the trouble. Diesels can run fine when warm with 250/275 PSI compression, but won't start/run well that low when cold. 350/425 PSI is needed for best results.

 

[JF in MI]

You pull the injectors and the compression tester has an adapter that takes the place of the injector or use glow plug holes which I don’t think your engine is equipped with.

Yes

I kind of figured I'd need a special adapter. I also am pretty sure I'd need a diesel specific compression gauge as I'm pretty sure mine doesn't go up that high.

 

[Harry in Ky]

If the compression is that poor, you don't really need a gauge (or adapters) to prove it. You should be able to see it in the blow by tube, as well as increased oil consumption. If you can narrow it down to one cylinder with "cold running" problems you can swap the injector with one from a good running cylinder and eliminate the injector as the cause. If you're that ambitious. On the other hand, if it's only for the first few minutes of cold starting, it runs okay after that, then live with it until it gets worse. If/when it does you'll know it. Running through the valve adjustment won't hurt if that's been a long time coming.

 

[JF in MI]

If the compression is that poor, you don't really need a gauge (or adapters) to prove it. You should be able to see it in the blow by tube, as well as increased oil consumption. If you can narrow it down to one cylinder with "cold running" problems you can swap the injector with one from a good running cylinder and eliminate the injector as the cause. If you're that ambitious. On the other hand, if it's only for the first few minutes of cold starting, it runs okay after that, then live with it until it gets worse. If/when it does you'll know it. Running through the valve adjustment won't hurt if that's been a long time coming.

Yea, it has plenty of blow by.

 

[Harry in Ky]

So who needs a gauge?

 

[JIM MN]

Do some troubleshooting? Low compression? Valves-- maybe stuck, broken rings? Also I would second the thought of adjusting that engines valves? Warm up the engine and check the valve clearance? Any tight clearances? If injectors are OK, valves good, I would pour in some injector conditioner in the fuel and run it. Put it on a good load, get the engine temperature up to a hi temp. Any change?

 

[JF in MI]

Do some troubleshooting? Low compression? Valves-- maybe stuck, broken rings? Also I would second the thought of adjusting that engines valves? Warm up the engine and check the valve clearance? Any tight clearances? If injectors are OK, valves good, I would pour in some injector conditioner in the fuel and run it. Put it on a good load, get the engine temperature up to a hi temp. Any change?

Did the injector cleaner thing a few months ago, no change.

 

[used red MN]

Yea, it has plenty of blow by.

Another thing you can do is leave the fuel off and crank the engine with the starter. Listen to the sound of the starter, as each cylinder loads the starter as it passes through the compression stroke. In two revolutions of the crank the engine passes through the entire firing order so all cylinders pass through the compression cycle. If the starter load and speed sound constant and than sound like it sped up and turned faster for a bit that is an indication one cylinder is down on compression. Some newer computer ran vehicles actually have an amperage coil on the starter cable and in diagnostic mode can give a starter amp load percentage change between cylinders.

 

[560Dennis]

Leak down test it.

 

[Destroked 450]

When’s the last time you checked the oil in the injection pump or changed it
A sticking plunger can cause a miss fire

 

[the tractior vet]

I’m looking for help/suggestions in trying to figure out what is going on with a Ford 5000 4 cylinder diesel misfire. It has a frequent misfire on one of the cylinders until fully warmed up then runs perfectly smooth (this only started this year). Mostly at the higher end of the RPM scale but sometimes at cold idle also. One of the times it was missing at cold idle and I cracked the lines to the injectors one at a time and found the #1 injector made no RPM difference with the fuel leaking out. The other 3 almost stalled the engine when allowed to leak. I changed out the #1 injector for new and it seemed to be a bit better at cold low RPM but still missed at higher. Swapped out the #1 and #2 injectors but the cold low RPM miss stayed with the #1 cylinder when repeating the leaking fuel test. It has a Simms-Minimec injector pump. Has anyone experienced this? I’m wondering if the pump has an issue but, once again, when it reaches full operating temperature it runs beautiful.View attachment 163275

If you have blow by then this tells ya compression is getting past the rings and no rpm change on number one tells me you have a issue on number one , be it a broken ring , stuck ring , or scoring , bad piston . Personally i have never dove into any of the ford diesel engines . What i do know is they are not a sleeved engine thus to rebuild they need bored and the days of the machinist dragging his potable boring bar out to the job site died back in the early sixty's . My one friend would if you twisted his arm hard enough but Dick has been gone now 30 plus years . during my time buying and selling i had many chances to buy nice Fords at the sales , they went dirt cheap because they all had sever blow by and the cost of rebuild one could easy tie up over five k and a ton of added man hours tieing up shop floor space for a couple weeks .

 

[JF in MI]

When’s the last time you checked the oil in the injection pump or changed it
A sticking plunger can cause a miss fire

Change it every spring. Did not note the hours but under 50. I can say that the time I determined the #1 cylinder was not working by loosening the fuel line diesel did squirt out just like the other 4 if that means anything.

 

[Dieseltech]

Change it every spring. Did not note the hours but under 50. I can say that the time I determined the #1 cylinder was not working by loosening the fuel line diesel did squirt out just like the other 4 if that means anything.

That's why it's a COMPRESSION problem. I have the same Ford 5000 that ran fine warm but would NOT start cold in a 60 degree building. Pulled the head and found the valves AND seats ground TOO MUCH, dropping the cold start compression heat needed for best cold starts. I got the head repaired with all new valve seats to raise the valves back closer to flush and now it starts MUCH BETTER cold than it ever did before.