# 4100 NO START



## Christopher Dunn (Dec 22, 2020)

Hello everyone, just joined the forum as I just acquired a 1999 JD 4100 that doesn't run. Previous owner said it was running great then started clanging and pinging really bad so he shut it down and parked it. He tried a new fuel filter but that didnt work so he gave up. 

I put in FRESH fuel and charged the battery at which point I tried starting it. It rolls over ok, however it refuses to fire. Getting white smoke out of the exhaust while cranking. Today I disable the glow plug system and gave a small snort of ether(into air filter, not intake manifold) and it acted like it was hydrolocking. Fuel solenoid is being activated. Checked all fuses, also tried cranking with radiator cap off to see if there were any visible signs of head gasket failure to rule that out. I have not yet cracked the injector nuts or the banjo bolt at the fuel pump to make 100% certain it is getting pure fuel and no air. Is there anything else I could/should check?

Thanks a million in advance.

Btw the particular tractor has 1060 hours and is pretty rough but came with loader and 6ft mower deck.


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## jd110 (Nov 23, 2015)

A lot of possibilities. Did you drain the tank before adding fresh fuel? If so, was there any sign of water in fuel? Could be the tank had a lot of water and filter and lines are full of water. Are you getting lots of white smoke or just a little? Also possible the original owner overheated it badly and scored the cylinders and now doesn't have enough compression to start. 
If you didn't already, I would drain and flush the tank, replace filter again, and blow out fuel lines from tank to filter and injection pump. Then bleed all lines and crack lines loose at injectors to see if you are getting good fuel to injectors. If getting good flow of fuel to injectors when cranking and it still won't start, you most likely have a compression problem. These little Yanmar engines are very difficult to start even with ether when compression is low.


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## thepumpguysc (Jan 25, 2015)

It takes a long time on the glow plug.. The last time I had one in the shop, I think it came out to 90 seconds before the cyls were warm enough to start..
But for sure, start w the basics. Remove the air cleaner..Clean fuel, new filters,
Loosen ALL the lines AT THE INJECTORS, bleed all the air out at the pump inlet..


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## Christopher Dunn (Dec 22, 2020)

jd110 said:


> A lot of possibilities. Did you drain the tank before adding fresh fuel? If so, was there any sign of water in fuel? Could be the tank had a lot of water and filter and lines are full of water. Are you getting lots of white smoke or just a little? Also possible the original owner overheated it badly and scored the cylinders and now doesn't have enough compression to start.
> If you didn't already, I would drain and flush the tank, replace filter again, and blow out fuel lines from tank to filter and injection pump. Then bleed all lines and crack lines loose at injectors to see if you are getting good fuel to injectors. If getting good flow of fuel to injectors when cranking and it still won't start, you most likely have a compression problem. These little Yanmar engines are very difficult to start even with ether when compression is low.


Yes, tank was drained and cleaned as well as fuel filter changed. I was just fiddling with it bleeding the lines and smoke turned from minor white sweet diesel to grey/black dull diesel puffing out pretty good. I will note that with it getting fuel now the hydrolocking is getting a bit more prominent. With the #3 line cracked it doesn't stop dead. Possible stuck injector? And what compression psi should I look for when testing?


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## thepumpguysc (Jan 25, 2015)

If your going to remove the injectors to get checked & while they are out, do a compression test.. anything over 300psi is good.. but your looking for much higher..(350-400)
Write down the #’s and compare the reading between each other.. anything over 10% difference is bad..
Next do an oil test.. Get a pump type oil can & pump about 5-10 squirts and retest again.. IF reading is much higher than the original test(100psi) would lead towards loose rings..
If your in the States, I’d b happy to test them..(free)..
& I’ll contact you about their condition..


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## Christopher Dunn (Dec 22, 2020)

thepumpguysc said:


> If your going to remove the injectors to get checked & while they are out, do a compression test.. anything over 300psi is good.. but your looking for much higher..(350-400)
> Write down the #’s and compare the reading between each other.. anything over 10% difference is bad..
> Next do an oil test.. Get a pump type oil can & pump about 5-10 squirts and retest again.. IF reading is much higher than the original test(100psi) would lead towards loose rings..
> If your in the States, I’d b happy to test them..(free)..
> & I’ll contact you about their condition..


When bleeding the injectors, how much pressure should "squirt out" between the nut, line and injector? Should it be pretty strong or somewhat limp wristed? 

Thanks!


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## Cvans (Sep 7, 2008)

It's acting like a hydro lock because the ether is detonating to soon when cranking that engine. Don't use it anymore as this can damage the engine and starter. Or at least have the engine turning over before giving it a small whiff.


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## Ed Williams (Jun 13, 2019)

I have found by experimenting that on my Ford 3 cyl diesel removing one end of the rubber hose at the intake manifold and inserting a B&D heat gun does a great job in preheating the intake manifold. I use the heat gun on a medium setting. I place my hand on the furtherest intake, #3, and when it is pleasantly warm to the touch, the diesel will start within 3 seconds of cranking the starter. Much better results than using the block heater and thermo start system. Have tested down to 12 deg F. Will probably add the block heater for a couple of hours if temp goes below zero.


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## jd110 (Nov 23, 2015)

thepumpguysc said:


> If your going to remove the injectors to get checked & while they are out, do a compression test.. anything over 300psi is good.. but your looking for much higher..(350-400)
> Write down the #’s and compare the reading between each other.. anything over 10% difference is bad..
> Next do an oil test.. Get a pump type oil can & pump about 5-10 squirts and retest again.. IF reading is much higher than the original test(100psi) would lead towards loose rings..
> If your in the States, I’d b happy to test them..(free)..
> & I’ll contact you about their condition..


In my experience, you will not get these Yanmar engines to start on 300 psi compression. The spec for engine in good shape is 498 psi and minimum is listed at 398 psi before overhaul or valve job is needed. Not sure why these small engines need more pressure to fire, but they sure do. Might want to look at breather tube while cranking. might see too much blow-by then. Another thing to check is make sure no hydraulic functions are not in neutral that would cause too much load on engine by having hydraulic pump in relief.


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## Christopher Dunn (Dec 22, 2020)

Cvans said:


> It's acting like a hydro lock because the ether is detonating to soon when cranking that engine. Don't use it anymore as this can damage the engine and starter. Or at least have the engine turning over before giving it a small whiff.





Ed Williams said:


> I have found by experimenting that on my Ford 3 cyl diesel removing one end of the rubber hose at the intake manifold and inserting a B&D heat gun does a great job in preheating the intake manifold. I use the heat gun on a medium setting. I place my hand on the furtherest intake, #3, and when it is pleasantly warm to the touch, the diesel will start within 3 seconds of cranking the starter. Much better results than using the block heater and thermo start system. Have tested down to 12 deg F. Will probably add the block heater for a couple of hours if temp goes below zero.





jd110 said:


> In my experience, you will not get these Yanmar engines to start on 300 psi compression. The spec for engine in good shape is 498 psi and minimum is listed at 398 psi before overhaul or valve job is needed. Not sure why these small engines need more pressure to fire, but they sure do. Might want to look at breather tube while cranking. might see too much blow-by then. Another thing to check is make sure no hydraulic functions are not in neutral that would cause too much load on engine by having hydraulic pump in relief.


So while reading I came across the service intervals and something caught my eye. Every 500 hours the valve lash should be checked and or adjusted. Previous owner I dont believe did any such maintenance so I removed valve cover and checked the valves that were loose and the best so far is .019. Can anyone inform me of the proper clearance? I read it should be .008. Just want to make sure I get it right. Thanks everyone!


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## Tx Jim (Jul 28, 2020)

Have you checked to determine if you getting good fuel flow from tank to inj pump? Is fuel tank venting? I agree on not utilizing starting fluid until the very last resort!


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## jd110 (Nov 23, 2015)

Valve clearance spec is listed as .006"-.010". I would adjust to .008 as you mentioned. If clearances are all very loose, it may have some effect on starting, but I wouldn't expect any huge difference.


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