MF 175 Perkins A4.236 diesel starting problems

DavidP, South Wales

Well-known Member
Hi,
I'm having some some starting problems with the above tractor after fairly extensive work has been carried out on the engine. The DPA has been overhauled and been back for checking. The injectors have been back to the repairer twice for new nozzles to be fitted after a test first time. A new lift pump is fitted. The timing has been adjusted in small steps in both directions.
The cylinder head has been overhauled and vacuum tested. New liners and rings have been fitted although they have not fully bedded in yet. Compression results are satisfactory. A new thermostart has also been fitted with a new main filter and tank filter.

The problem is that the starting is not as good as it should be. It appears to be firing on one initially with a lot of smoke. When the engine starts to warm it is OK. It frequently will cut out almost immediately after the first start. When restarted there are no further problems. All of the lines have been checked for possible air intake. A new air filter housing has also been fitted.

Has anyone encountered any problems like this before? Thanks in advance for any suggestions.

DavidP, South Wales
 
I had a 180 years ago, same engine that needed about 20 hours use before it started better cold after all new sleeve assemblies were installed. This model would have started better if the injection pump had the advance feature to retard timing, then advance after startup. Dad's 180 was never as good as the Super 90 on cold starting. What is the actual compression PSI? Another critical area is the valve recession, if the seats and valves are both ground and head surface is not milled the compression WILL drop enough to effect cold starting, but will run fine when warm. Guess that's why dad uses the block heater so much when cold!
 
Hello
25 years ago I ran into the same problem.We found one of the timing gears was marked wrong.I believe it was the cam gear.This tractor would smoke like crazy, but once it started and was warm it started fairly good.The other thing I remember on the Dyno it put out more horse power the it should. You must check the valve timing with a dial indicator.I hope this helps.This was one of those mops that made me want to be a carpenter . Good Luck Lance
 
What are the temperatures when you try starting? To be honest your intial start sounds like it has air in the fuel system. Have you tried pumping the primer prior to you first start to see if it acts differently. Where is the fuel tank on a 175? Directly above the engine?
 
Sounds like the Kubota V1702 engine I'm currently rebuilding. The rings were worn out pretty bad (not enough compression). Since you have new liners, and such I'd check the cam then the injector timing.


Edit: Sounds like the cam timing is retarded, holding the intake valve open longer on the compression stroke.
 
Holy cow David.... if you are having problems... the rest of us are doomed...
Ether. Need any? I happen to have a pallet or two I can lend you....
And how bloody cold is it there lately? And is the petrol people playing with your fuels like they are here?
My new to me Dodge ram with 24 valve Cummings diesel has 2 batteries and a radiator hose heater cord... and on a cold morning... the glow plugs are..... let's just say it is not a good getaway car for bank robbers....
Hopefully the rebuild is just a little too fresh for the weather.... that's all the words of wisdom I can come up with just now... good luck!!
 
I had a similar problem with a 180 a while back and we finally got it straightened out by replacing an injector line. There was no sign of leakage but a new line cured it. Can't remember how we determined which line it was.
 
Hi David, had a starting problem on a 4.236 that I had just rebuilt out of a Manitou fork lift truck. Like yours, full rebuild, faced head and new valves, new pistons and liners, rebuilt pump and injectors and new thermostart. Engine bled up ok slackened one injector pipe plenty of white smoke but no fire. After trying several times I cheated and gave it a one second burst of the dreaded easystart and it started right up, tightened inj pipe and it run ok. Stoped it and it started up instantly and was never any more trouble. Apart from my little story I can not help you but I will go and think about it. MJ
 
Hi everyone,
Thanks for all your wisdom. We all come across a 'Jonah' at some time and this appears to be mine.
It has started cutting out after first start now so it seems more fuel based at the moment. Going out to the tractor in the next day or two to have another go. The timing has not been disturbed but I'm grabbing at straws.
Thanks all.
DavidP
 
If it starts missing after starting there is one more thing to check. On top of the filter base there is a constant bleed fitting that if plugged will not let air out of the filter base. Is usually on the final filter tied in with the injector top bleed line, may be a straight fitting or a banjo bolt. CAV DPA pumps have no internal vent to handle air at the inlet on early models like the later pumps do. Brother had a 1105 MF that had us both scratching our heads awhile until we found the vent bleed bolt plugged. You can usually here the return going back to the tank while working the hand primer if the tank is not full, or best way is to remove the line. US tractors used 3240848 or 3241F360, both fixed phase timing, and 23 dgrees BTDC on engine. Not sure if yours is the same if it's a UK built one. US 100 series never came with the thermostart unit installed either, while the 35, 50, 65, 85, and Super 90 did.
 

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