New performance starting issues

[liam]

Hi Everyone,

I rebuilt the engine in my new performance. The engine had new pistons and liners, head was reconditioned with new valves. Pumps and injectors were also reconditioned. The crank was reground and I fitted a new oil pump and cam shaft becouse the hard facing on the old one was beginning to break up.
The tractor was very hard to start when I bought it but I just put it down to a very worn engine. However it is still the same, turns over with loads of white smoke. It will start after about 30 secs but it still runs rough for about a minute and then it is fine.
I have double checked everything such as the pump timing and the valve clearance. It has done only about 5 hours but no hard work. Is the lack of hard work the problem or should I check for anything else? It drives fine and appears to have loads of power and very little smoke when it warms up and it runs very smoothly. Any thoughts?

[thestig246]

hey, congrats on getting it back together and running! you are doing better than me lol..

from what you have said i would take it that it may just need a good days graft. if the timming is bob on then i wouldnt think it was anything too serious..

what is your battery and starter like?? a sluggish motor may be making her a poor starter perhaps?

hope i may have been of some help

dan

[AdrianNPMajor]

Hi Liam

You have been very thorough. That's a full engine rebuild. I know you have checked the injection pump timing and the tappets, but the symptoms still shout timing issues. With the excellent compression that you now have, it can't be anything else. As I'm sure you know, the timing for your engine with a Minimec pump is 21 degrees BTDC. Re the tappets, inlet valves have a clearance of 0.015"; exhaust 0.012".

Best

Adrian

[liam]

Thanks for the replies everyone ,Adrian I thought it was pump timing and I played about with it but it only makes it worse so I set it back as per the book,I have rechecked the tappets and they are okay.If the pump timing was out would it not run poorly and be down on power even when it warms up ? Maybe as the stig says it just needs hard work.My other supers engine is totally worn out and it starts very easy . I am baffled by this and I dont know what to do with it next apart from taking the engine apart which as you can imagine Idont really fancy doing. Liam.

[AdrianNPMajor]

Hi Liam

Did you get the timing gears lined up correctly when reassembling the engine? I'll answer the question for you - of course, you did. Meaning, it's such an obvious thing to get right, it's not the kind of thing that gets overlooked.

So where does that leave us? Excellent compression, refurbished injection pump feeding refurbished injectors. Tappets adjusted correctly. Injection timing correctly adjusted to 21 degrees BTDC.

All the above should lead to a very short starting sequence and above all no white smoke. As you know, the white smoke is uncombusted diesel. To go over the basics, compression ignition is all about the heat produced by the compression of the air in the cylinder. The diesel spray from the injector needs to arrive at the right moment in the cycle to combust. This is what is not happening with your engine. When she finally does start and run, the heat build-up compensates for the initial lack of heat that should have been produced by the winding of the engine by the starter motor - this explains why she runs eventually and seems to run well. If she doesn't start well though, she cannot be producing full power when warm, even if she seems to.

Those are my thoughts. I could be wrong!

Wonder what other wiser members think?

Best

Adrian

[BearCreek Majors]

Pop the cover off of the injection pump and watch to see if the rack is moving to full throttle when you hit the clip. If I try to start mine without hitting the clip they usually crank for a time while blowing out lots of white smoke until they fire.
Remember to keep it clean, any dirt getting in the pump will trash it.

Pat

[Pavel]

Some while ago my SMD started to give starting problems when previously it was an instant starter. The problem turned out to be a slight leak [well a weep more than anything] in the fuel line near the tap even though I always turned the tap off. If I used the SM again the next day -- no problem. But leave it for a few days and the line pressure dropped and because of the vacuum this created, air was drawn into the system meaning it had to be bled out. However leaving the tap on stopped this problem as the weight of the fuel in the tank replenished any lost.
Another thing that crosses the mind is moisture from condensation accumulating in the fuel tank. White smoke and bad starting are also a symptom of this.
Having completely overhauled the engine you would have renewed the fuel filter[s] and put oil in the Minimec -- Yes?

Pavel

[liam]

Hi all , thanks for the replies .When I press in the cold start button I can hear the rack move in the pump but maybe it is not moving enought .I will take off the plate tommorrow and have a closer look. Liam.

[dexta roadless]

One thing comes to my head when reading this. A couple of months ago I had the same problem with a Super Dexta. It turned out to be the feed pump. one of the valves were stuck open, so it didn't create pressure.

[Dandy Dave]

I had a problem with my Power Major that drove me nuts. Every once in a while I would be going along and the tractor would just up and die. I would get off, pump the lift pump a few times, and then the tractor would be fine for hours. One day last year I went out to the shed to start it and it acted like it was starving for fuel. I bleed it as there was some air in the line and had some trouble getting it to go even after that. The lift pump did not act right. I finnally siphoned the fuel out into some cans, and while running the fuel though a paint filter a piece of leave was found. The piece of leave would move around the bottom of the tank and every once in a while it would get near the tap inlet and the suction of the pump would pull it down and prevent the flow of fuel which lead to some air in the line also. I have not had a problem since. Be sure that your fuel flow from the tap forward has sufficient flow. Dandy Dave!

[liam]

Hi all .today i checked the rack in the pump and it is moving fully forward when i press the button so it appears ok . All pipe joints are tight and there are no fuel leaks .The lift pump is new ,it was fitted when I put the engine together and it pumps plenty of fuel through the bleed screws.The tank was washed out and I fitted a new filter on the tap so there is no blockages and the tank is about half full. I cant think of anything else .liam

[Pavel]

Since you've just about checked and done everything possible to find and rectify the problem it might be time to look at the not so obvious.
Check the coolant level.
Before starting lift the bonnet and remove the rad. cap. Fill the rad to the brim, leaving the cap off, and then start the engine. Water will leak out until it warms and reaches a set level. [You may have to pour in another cup-full so that you can still see the water level.] Then watch it to see if any bubbles appear. If there are you have a leaking head gasket. If not -- time for another cuppa and a Rodin thinker session.

Pavel

[Kjetil]

Hi

You said you had another Super. Why not try the Injection pump from that engine?

[Dons62FSM]

Since so many other things have seemingly been ruled out, I would do a compression check. It seems possible that the rings or the valves may not be well seated.

[liam]

Hi everyone ,The pump is different on my other super as it is a blue end orange model.The head has had new valves fitted and I also fitted new pistons rings and liners,the engines seems to have good compression when I turn it over with aspanner on the bottom pulley.

[Dandy Dave]

Maybe you just need to get the tractor out and work it. Get a load on it like a disk harrow and give it a good workout for 8 or 10 hours over a period of time. If it does not have the power to do this then the Injection pump and Injectors will need to be recalibrated as the settings are incorrect. Dandy Dave!

[liam]

Hi Dandy Dave,I am beginning to think that may be the case ,It needs a good workout as I have checked everything else .I am planning to do some topping with it later on in spring when everywhere dries up and I will report back .Thank to everyone for their help. Liam.

[Matt 1944 N]

Hi,
My NPSM is exactly the same as this and it had had a nearly full engine rebuild before i sprayed it and it started and run fine, when i brought it in the workshop and stripped it for respraying and finishing the restoration i changed the camshaft as i had read about them wearing badly and the old one had. Since this it has been exactly the same as your tractor it will crank over and eventually start and then when it does it white smokes loads until it has warmed up and then it is perfect and runs fine. I have tried another injection pump, lift pump, checked the compression, valve gaps, injectors and none made any difference. I am just rebuilding it from putting a genuine cam in to see if that will fix it. Was the cam you fitted a sperious one or a genuine one?

Matt

[liam]

Hi Matt ,It was one from Agriline .The thought had crossed my mind that it may be at fault,Can you please let me know does it fix your starting issues,Ithink you may be on the right track.Thanks for your reply .Liam.

[Dandy Dave]

Comparing Apples to Oranges, but I have a friend with a D-8 Caterpillar. He Had the same sort of issues after a rebuild with an aftermarket cam. (Not a job that I did myself.) Replaced with a Genuine Cat cam and the problems were solved. Some of that A.M. stuff is total trash. Dandy Dave!

[liam]

Hi all just a quick question ,if I was to change the camshaft would i need to remove the engine from the tractor. I am thinking the followers will drop down with the engine upright as it is in the tractor.

[Matt 1944 N]

If you have good cam followers which wont need replacing you can do this if you can get them pulled up away from the cam to hold them up, the worst thing is that you have to remove the tombstone to take the engine front plate off to allow the camshaft to be pulled out. I will let you know as soon as i have run mine properly to see if it is improved

[liam]

Thanks Matt for your reply,thats a good idea for holding them up that you done.My cam followers are new so if I have to do the job it should not be to bad,I am looking forward to hearing how your engine runs ,Liam.

[Dandy Dave]

I hope you won't need that battery charger soon. ... Looks like many of your shop tools are.. er, Tied up at the moment. Dandy Dave!

[Pavel]

How about using a pair of long needle point pliers that have a 90 degree bend on the end of them? I'd hate to wriggle a camshaft in and out with that lot working on a wing and a prayer.

Pavel