Fergie TEF missfire at idle

[MrNoo]

Eve all, rebuilt a TEF, new liners/pistons etc head faced, new guides/valves/springs etc the works. Timing is spot on along with Spill timing. Starts and runs fine, pulls well with no smoke etc but when you put the engine at tick over it tries to misfire and run on 3 or more like 3 and a half. Pump is chucking plenty of fuel out, injectors were serviced/overhauled so I hope to rule them out. It does puff a small amount of smoke out when at tick over/miss fire. I did think that maybe I have got a tight valve clearance but would have thought it would have been missing all through the rev range or maybe a leaky injector (that is not cutting off flow) but am pretty much running out of ideas.
Vacuum side of the pump is fine (new seals and diaphragm) small amount of wear at the venturi spindle but nothing major (although I will stick it on the lathe and make some spindle bushes) to rule that out.
So any other ideas??

 

[clunk]

sounds like diaphragm ether leaking or miss aligned its very easily done on the simms pump set up last one i did i had it apart 4 or 5 times before it was right and didn't see anything wrong any of the times lol

 

[MrNoo]

sounds like diaphragm ether leaking or miss aligned its very easily done on the simms pump set up last one i did i had it apart 4 or 5 times before it was right and didn't see anything wrong any of the times lol

Will get it apart again and have a butchers, checked valve clearances, they were a little tight but after adjustment, no change. So have a few things to look at tomorrow

 

[REStracTORATION]

Can you turn pump alittle
Had this on a nash the other day after a full rebuild
I just noticed the pump wasnt just alligned
So turned it back to marks and spot on no misfire

Just a thought process of elimination i guess

When its running rough can you crack a injector to help narrow it to a clyinder.

 

[MrNoo]

Can you turn pump alittle
Had this on a nash the other day after a full rebuild
I just noticed the pump wasnt just alligned
So turned it back to marks and spot on no misfire

Just a thought process of elimination i guess

When its running rough can you crack a injector to help narrow it to a clyinder.

Yes, it's No4 pot, have tried to move the pump (fairly limited) with no difference, know the spill timing is spot on but can double check it tomorrow. Just baffles me as to the fact it clears and runs fine once revs build.

 

[REStracTORATION]

Ok well at least that side ok then,
Tick over set slightly low possibly sounds as if fuel is shutting off to far



Plug computer into her be idle speed sensor

 

[JWL]

Allmost as if one of the injectors isn't getting enough or too much fuel when at tick over/when the injector pipes are at a lower fuel rate/pressure

 

[MrNoo]

Allmost as if one of the injectors isn't getting enough or too much fuel when at tick over/when the injector pipes are at a lower fuel rate/pressure

Yes, although having had them done I would have hoped they were ok, will take No4 injector out and connect it up and run engine and see what is going on. The pump seems to be producing enough pressure esp as it runs fine at full chat up the farm track.
Will try another diaphragm and redo the bushes on the throttle venturi today and see if we get anywhere further forward!!

 

[Philip Watkins]

Yes, although having had them done I would have hoped they were ok, will take No4 injector out and connect it up and run engine and see what is going on. The pump seems to be producing enough pressure esp as it runs fine at full chat up the farm track.
Will try another diaphragm and redo the bushes on the throttle venturi today and see if we get anywhere further forward!!

How about swapping 2 injectors, see if it misses on the same cylinder or the same injector. Will show whether it's injector or pump.

 

[Mursal]

Yes swap the injector ................
Would there be lift in the injector pump shaft, was the rear bearing changed?
If the shaft was down it would reduce fueling and possible No4: phasing/cylinder timing, especially at low revs.
If you loosen the exhaust manifold, wonder if its wetting the exhaust port on that cylinder?

Or it just might be too pampered ............

 

[MrNoo]

Yes swap the injector ................
Would there be lift in the injector pump shaft, was the rear bearing changed?
If the shaft was down it would reduce fueling and possible No4: phasing/cylinder timing, especially at low revs.
If you loosen the exhaust manifold, wonder if its wetting the exhaust port on that cylinder?

Or it just might be too pampered ............

Lol!!! It's supposed to be my new match ploughing tractor!!!
Spent all day rebushing the venturi!! tried another diaphragm, seemed better but still fluffed at tick over!! Re did the spill timing, was spot on, messed around with the threaded rod that connects to the dampener on pump.
But it still does it!!! Not so much of a miss more of a "fluffing" at idle

Not had the pump apart at all, just cleaned it out with compressed air/diesel. If I hold onto the injector pipes, you can definitely feel pulsing from 1, 2, 3 and a weaker pulse from 4, so maybe the pump needs looking at?? I have never taken one apart before, I guess a specialist "pump man" would be required. I may get my other half to video it then you can see/hear

 

[Mursal]

Good idea, that's if the other half is sympathetic to the cause, don't go causing "hassle" ............

Yes, running the pump in the bench would show up a bad element.
But, if you measure the volume of diesel spat out while cranking over, would that show a problem, comparing it with the other three? I wonder, can you take the governor off the back of the pump, to inspect the rear of the shaft.
If you could get the lend of a pump for a few hours, see if it clears ...........

 

[MrNoo]

My ploughing mate Trevor popped up, it's hunting, We changed the diaphragm, sealed around it with a bead of silicone, blew out and re-bled the injector pump/injectors, re did the spill timing and still it persists.

 

[Mursal]

Would you a have an inlet manifold leak, a very small leak wouldn't be noticeable at higher revs
Spray a bit or WD40 on the joints to see can you get it to clear?
Might be worth cracking the vacuum pipe open to see if the engine note changes, not to much though as the spring pushes towards full revs, if I remember correctly.

 

[MrNoo]

Would you a have an inlet manifold leak, a very small leak wouldn't be noticeable at higher revs
Spray a bit or WD40 on the joints to see can you get it to clear?
Might be worth cracking the vacuum pipe open to see if the engine note changes, not to much though as the spring pushes towards full revs, if I remember correctly.

Yes, we cracked the vacuum pipe and could hear it sucking well and engine rpm speed increased. I will try the WD40 trick although to be fair the inlet manifold is just a log style with venturi the one end, so I could have a gasket out of kilter!!
Certainly has had me stumped and I have done quite a few of these!

 

[Flat 10]

Unhelpfully, l thought they all did that.
Smart refurb.
Not relevant in any way but
I have a dexta that's similar.

 

[Right-arm fast]

Eve all, rebuilt a TEF, new liners/pistons etc head faced, new guides/valves/springs etc the works. Timing is spot on along with Spill timing. Starts and runs fine, pulls well with no smoke etc but when you put the engine at tick over it tries to misfire and run on 3 or more like 3 and a half. Pump is chucking plenty of fuel out, injectors were serviced/overhauled so I hope to rule them out. It does puff a small amount of smoke out when at tick over/miss fire. I did think that maybe I have got a tight valve clearance but would have thought it would have been missing all through the rev range or maybe a leaky injector (that is not cutting off flow) but am pretty much running out of ideas.
Vacuum side of the pump is fine (new seals and diaphragm) small amount of wear at the venturi spindle but nothing major (although I will stick it on the lathe and make some spindle bushes) to rule that out.
So any other ideas??

Delivery valve in FI pump sticking or not seating etc or injector as you have checked most other things. Or you have a piston the wrong way round but it's probably indirect inj isn't it.

 

[MrNoo]

I think I will have the pump off and gone through, took it to a ploughing match today and spoke with some other Fergie bods and they suggested it was the pump that was at fault. Be good to get to the bottom of it! Pistons were all assembled the same way around, there is no "front" or arrow markings on them, all Bepco so decent quality. I did my engine and another pretty much at the same time, so they both went together the same and no issues with T'other engine.
No they dont all sound like that when fully sorted, my girlfriend's tractor is as smooth as silk, I did the engine on that one too!

 

[Sussex Martin]

My ploughing mate Trevor popped up, it's hunting, We changed the diaphragm, sealed around it with a bead of silicone, blew out and re-bled the injector pump/injectors, re did the spill timing and still it persists.

Yep, sounds very much like a TEF20. Mine didn't sound dissimilar but I thought it was normal . Sorry, doesn't help I know.

 

[tomlad]

Id describe it as hunting

My thoughts air leak . Bad injector . Pump element . Guevenour