How to / DIY > Engines

Wonít start when hot


Hi, first post, Iíve had a search here but havenít been able to find info Iím after.
Iíve a dumper with a 3cyl, air cooled engine (TR3 ?).
Starts fine from cold but if stopped when hot it wonít restart. If it get a jolt when at idle that causes the revs to drop (clutch out too fast or tip heavy load suddenly) the engine cuts out and refuses to restart.
Sometimes if I play around with the stopper lever at the pump it may restart. If stopper lever is not 100% against its stop it will not start hot or cold. I get the feeling that some adjustments around the stopper lever (or govener) arenít helping my cause. There is no more external adjustment left on the mechanism.
Battery is fine, starter is fine, fuel flow seems fine (transparent filter housing in fuel line from tank).
Starts fine from cold, runs fine all day.

Any ideas whatís causing my problem ?

i am not familiar with your specific engine, however

from what you are describing, and based on the fact it will restart when cold
i am thinking maybe a sticking governor spool, maybe gummed up.

when the engine rev's up when you drop the load on the engine by too fast tipping the dump
or clutch the governor weights fly out and the system reacts, drawing the spool back toward no fuel position, the governor normally would catch this and correct for overshoot to no fuel, but if the spool is carboned up on the shaft, or the flyweights are hanging up?  who know's, but my bet is the governor can't catch itself and correct.

i have seen it happen on other engine's with mechanical governors, not often but it does happen, as does a sticking injector rack, which might even be more likely, seen that happen many times over the years.  i would first check all the injector racks, and make sure they move freely from no fuel to full fuel without any sign of binding.


probably someone(s) here that can be of more help

bob g

Good advise mobile-bob. I too feel the racks maybe a big part of the problem and then look at the governor set up. Also you really need to confirm that you do have full flow of fuel to the rack. Looking at the filter tells you nothing. Remove the fuel line where it attaches to the rack and make sure it is a good constant drizzle.
It will be a huge help to identify your engine so some nice clear pics of it and the engine number plate will help sort that out. Once established what engine you have then a manual would be good to find for it.

Diesel Engineering:
It sounds to me as you cold have an issue with the pump linkages or possibly an issue with your auto excess fuel control. These TR engines are a little fiddly to set up and plenty of parts to wear or stick. Would suggest in the first instance to remove the gear end cover, and the plates below the injection pumps to ensure everything is in its place and operating freely.

Thanks for the input lads. Apologies I havnt replied earlier. I havenít gotten to touch the engine yet but Iíll hopefully get near it this week.
Just to add, when cranking hot thereís zero smoke or smell so not getting diesel is the issue I reckon.
Iíll get a pic of the engine plate and pull that end plate off to start with and see how all looks.


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