My shop has been working on a John Deere M-Gator with a hot start problem. It starts fine when it's cold, but if you drive it a while and then shut it off, it doesn't like to restart. We changed the air filter, replaced the batteries, and cleaned the fuel filter. I'm looking for ideas.

More information:

John Deere M-Gator, 3 cylinder Yanmar diesel engine. Glow plugs appear to work during cold starts. The engine has about 800 hours on it. The old air filter was several hundred hours past due for a change. The thing has had at least two oil changes in its life, but is probably still on the original oil filter. (Parts availability SUCKS over here). The engine may have been run without an air filter in very dusty conditions at one time. Cranking speed seems ok. It sometimes blows gray or black smoke when cranking. The engine has plenty of power once started. I do not have to ability to do a compression test (no tester). I'm thinking the motor is toast, but I'm hoping someone will come up with a fix I hadn't thought of.

Edit: Can't...fix...typo...in title...

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Engine may be "dusted" if run without an air filter in those conditions over there. A compression check is really in order if at all possible.

Also, when cranking, try holding the throttle wide open and cracking the connectors loose on the injectors and see if you see fuel spurting out indicating that indeed, fuel is being injected.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

on my john deere lawnmowers they use a solenoid to control fuel flow to the pump,it's mounted right on the side of the pump.when you turn the key on you should here a snap,this is the solenoid energizing and opening up the fuel flow.when these go bad like my 430's did they seem to work fine cold but when hot they seem to take a little more juice to energize,usually you just have to take your finger and help it to open and it will hold it there.also they have numerous safty switches that have to work.

Thanks. Dusted is a likely possibility, but unfortunately one that I can't do much about. I will look for a fuel solenoid on the pump the next time we get the Gator in the shop.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

If the engine is dusted how come it starts fine cold. Cold is when its hard to start and engine especially a diesel. When trying to start hot give it a shot of wd 40 and see what happens.

My 99 E300 had that problem. Starter was the answer. Heat soak was the problem. Drive all day and it was fine. Shut down and try to restart and it takes a lot of cranking.

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

I checked for the solenoid mentioned above. No joy. My new crazy idea is that the valvees have never been adjusted (200 hour recommended interval), but the valves still seal when the engine is cold. Then after the engine gets hot, the valve stems elongate enough that the engine starts to bleed off compression and doesn't want to start. I finally have the Gator in the shop, so I'll find out soon.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Adjusted valves. All were way loose. Cold starting has gone from good to perfect. Hot starting is still a no go. It smokes when you crank it hot, so there's no doubt it's getting fuel. Cranking speed might be a touch slower hot than cold, but not by much. I don't think that's the problem. Anybody got any other ideas?

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

is there a hot fuel Adjustment somewhere?

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed

Why would hot cranking speed be even incrementally slower than cold cranking speed? Oil's warm, engine clearances have increased due to heat...

...perhaps increased too much. What condition are the cylinder walls in?

well i checked jdparts and for one i don't know what gator you have and second the one i did look at didn't have a time control relay.your best bet is go to weekendfreedommachines .com into forums-resto and repair and tell them your situation, maybe someone there has one and has had the problem.

Wonder if the timing is wayy off?

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg