# McCormick IH 434 Starting problem



## darryl hutchinson (Nov 21, 2020)

Hi Guys,
looking for some pointers following an engine rebuild and engine starting.

I have dispensed with the old style glow plugs and installed 12V ones. I have bled fuel firstly to bottom bleeder on CAV pump (fuel gushes out when screw is open), then undone all the 3/4" unions on the injectors themselves (fuel squirts repeatedly on all injectors when attempting start up), so this all looks good.

I get smoke, and progressively more smoke when cranking, but after say a good 30 seconds of cranking, engine fires up BUT immediately cuts outs. No re-start right away but after a while it will fire again but immediately cut out.

How about a 1,2,3 on what to check next from the experts, please.

Other points to note. I am happy timing wheels are all matching. The mark on the CAV pump mounting aligns with the bottom of the 2 lines on the engine casing. I cannot seem to move this easily (in neutral) as seems very tight. Is it likely this matters, as long as the pump line is somewhere between the 2 engine case lines? Also new lift pump just installed.

Thanks
Darryl


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## Fedup (Feb 25, 2014)

While I'm probably not much help to you here, I am curious. Did the engine run with this same pump and timed approximately where it is now? Can you describe what "engine rebuild" consisted of?


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## darryl hutchinson (Nov 21, 2020)

1 cylinder was broken on inspection, so a rebuild kit was obtained and fitted. All put back as was before, same pump, same position etc


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## Fedup (Feb 25, 2014)

Again, did the engine run before being torn down? If so, then I have to doubt that the pump or anything fuel related is to blame for your current problem. I'd be more inclined to question the fit of the replacement parts, the attention to detail on assembly, measuring/checking clearances, tolerances, things like that. Over the years I've been through more diesel tractor engines than I care to count and I know from experience that in most cases when a fresh engine has that much trouble getting started, it's all too often the result of something that was missed/overlooked or done incorrectly on assembly.


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## darryl hutchinson (Nov 21, 2020)

Anybody else


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## BigT (Sep 15, 2014)

Fedup is an expert on tractor's and tractor engines. You have not answered his question: 
"Again, did the engine run before being torn down?"


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## darryl hutchinson (Nov 21, 2020)

Yes it did. Was black-smoking so decided on a rebuild and found one cyl broken. 

Can't see what could possibly go wrong with re-assembly and we took phone shots of unfamiliar things before we started.

Would be interested to hear from anyone having this kind of problem following a rebuild and what they did.


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## Fedup (Feb 25, 2014)

"Can't see what could possibly go wrong with re-assembly" ???

Would you care to share any details, like what the "kit" consisted of, how far down the engine was dismantled during the process, what (if anything) was done in the way of machine work, or how you confirmed the parts in the kit were indeed the proper match for your particular engine?


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## darryl hutchinson (Nov 21, 2020)

Kit was a BD154 rebuild with sleeves, cylinders, pistons rings, shell bearings, head gasket etc. These were fitted. All else was left "as is". No skim needed. No machining beyond pressing.


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## Fedup (Feb 25, 2014)

I have no books on the 154 engine, but just looking at the CNH online parts diagrams the pistons in the drawing appear to be flat top. That would mean the combustion chamber is a recess in the cylinder head. Is that correct? Nothing was done to the head during the process? No work done on valves, guides, seats, etc? The head was pretty much installed as it was when removed, other than cleaning? Same with the injection pump and injectors? Nothing done there except for external cleaning?

And it started well enough before all this work was done, even with one bad cylinder? Your description of what it does when attempting to start makes me think the pump is working, or there would be little if any smoke while cranking. Timing shouldn't be that far off if the external marks match where you started. I realize I'm only guessing here, but what comes to mind first is that when cranking the engine isn't developing enough heat to ignite the fuel. Even with new glow plugs (and I assume you're using them liberally during attempts) it's just not enough. That brings compression into question. Nothing was done to the valves or seats? I've seen cases where grinding severely worn valve faces and seats resulted in the valve heads being recessed into the head far enough to actually affect compression enough to cause hard starting. That should not be the case here if nothing was changed. The piston crown to head clearance at TDC also comes to mind. The pistons themselves or the thickness of the head gasket. Either could be a factor here. 

I wonder does the tractor have a block or external coolant heater? If so I'd be curious to see what effect warming the engine as much as possible might have on the situation.


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## Busted Tractor (May 22, 2018)

I have never had a diesel that would not keep running after it started. Unless there was another issue. Once a diesel fires there should be enough heat for the next power stroke. Have you tried to reheat the glow plugs? or keep the glow plugs operating? does it still die? Usually to cold start a diesel will emit white smoke (unburned fuel) once it starts the smoke usually turns to black and then clears. When I read the first post I remembered some thing I had done years ago. I didn't want to put the air cleaner on so I clamped a rag over the air intake. Yep started, died, and wouldn't restart. Some one removed the rag---engine started. My checks would be #1 is the air intake clear with nothing that can pop up and block it. #2 check fuel flow at the pump does it run out or just dribble? Check all fuel lines and filter, don't forget the tank outlet. # 3 Possible injection pump issues. after it starts does fuel keep coming from the high pressure lines? Does it slow as if you were shutting it down or just quit with no smoke. If the fuel stops coming from the high pressure lines would indicate a governor issue and the pump needs service.


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