# TN95FA......getting hard to start



## Keshka Kotera (Dec 27, 2017)

Well I noticed this trait on about 1 in 5 starts this summer. Tractor is used about 3 to 4 times per month. So I had mounted my snow blower on it a couple of weeks ago and I went out today to "do the driveway". It is chilly, not COLD around 25 degrees. Last year, she would always light right up even without the preheater. Today, I cranked on an off till I killed the CAT battery. Tried starting fluid. With that it would almost outrun the starter. So hook up the big charger and troubleshoot. Fuel level, check. fuel getting to pump, check. Fuel leaving filter, check. Cracked two injector lines, has pulses of fuel. Hook up aux bat and now charged CAT bat. Good fast crank but still not taking off no matter what the throttle setting.

Finally after all this I found I could get her to kinda idle at 1/3 throttle but NOT right. Fluke temp gun showed just maybe the back two cylinders firing. After about ten minutes, a slight increase in RPM, another 7-8 minutes and she took off, running smooth on all cylinders. WTF?

Blew the fluff out of the driveway (60 minutes at full throttle). Am looking at this Bosch injector pump. I can identify the fuel cut off solenoid. Thinking it must have been ok or no fuel at the injectors. Have no idea how that K something WAX valve motor thing works or how much it should move (or not?). I don't get it. If it's broke, I would find it sooner or later. But to take off and run fine after all that? What the hey? 

I have $1500 dollars in manuals and parts books but them Newholland types say nothing much about how it works...just how to take it apart.


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## thepumpguysc (Jan 25, 2015)

You do not want to take it apart..
The wax motor as its hooked to the side of the injection pump, controls the "cold start" timing.. in the cold start position its pulled back in most cases & moves forward VERY SLOWLY as it warms up [wax motor].
In the fully warm position it should touch or almost touch the small metal arm/bracket infront of it.
It gets its voltage from several places, 1 being the water/coolant temp..
I don't think THATS your problem tho.. it sounds as if the fuel "supply" isn't there..
Possible fuel jelling?? dirty filters?? water in the filters that is jelling??
25* isn't "chilly".. its PAST FREEZING..
Change your filter & dump some fuel from it, in a container & set it outside for a few hrs... IF theres water in your fuel, you'll see it..
Good luck & let us know how it works out.


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## Guest (Dec 27, 2017)

I drove a semi many years ago and in that kind of weather our instructions were to add a can of stabil to each tank (100 gallons) of fuel and to keep the tank heaters on. the pumpguysc said all I could say.


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## willys55 (Oct 13, 2016)

thepumpguysc said:


> You do not want to take it apart..
> The wax motor as its hooked to the side of the injection pump, controls the "cold start" timing.. in the cold start position its pulled back in most cases & moves forward VERY SLOWLY as it warms up [wax motor].
> In the fully warm position it should touch or almost touch the small metal arm/bracket infront of it.
> It gets its voltage from several places, 1 being the water/coolant temp..
> ...


you beat me to it, spot on!


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## Keshka Kotera (Dec 27, 2017)

thank you all, I will remove and drain the filter checking for water. I do have stabil in the fuel and during my testing, no signs of gel or wax.


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## Keshka Kotera (Dec 27, 2017)

Well out in the snow again all day yesterday and half today. I found a loose connection on the cutoff solenoid.....fixed. The wax motor is shot.....removed.

things of note. wax motor apparently pushes out it's rod when power heats the wax (slowly). The injector pump is spring loaded to move to the "run" position and pulled to the start position by the wax motor when cold (I am about 80% sure of this) Since my wax motor does not move....ever, I had a hard time understanding how things moved to help cold starting.

Current problem. No fuel. I base this on no smoke when cranking (white or black) and of course it won't run other than a few seconds on starting fluid. I removed the banjo connector on the top right of the injector pump were it is fed from the line leading to the filter. When I operate the manual fuel pump prime lever, clear fuel and no detectable foam or bubbles. When I remove one of the lines going up to an injector I DO have foam and air. I have confirmed this by attaching a clear tube to the fitting exiting the injector pump. I know that air in an injector line means that no fuel will be shot into the cylinder. I am thinking my injector pump may be bad.

How do I test it to find out for sure as I don't have $2k to spend on a rebuilt one. (where could this air be getting into the system?)


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## thepumpguysc (Jan 25, 2015)

You had it running in Dec.?? what did you do?? Lol
How did you test the cold start sol.?? IF you take it out..You have to have 12v to the spade & the - on the threads.. & wait 3-5 minutes for it to move..
Your location says, Summerville?? Summerville What?? Theres a Summerville S.C. 20 miles from ME..


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## Keshka Kotera (Dec 27, 2017)

I did get her running about a month ago....after trying and trying, it started running on two cylinders. It did not want anything above about 1/3 throttle. I used a temp gun on it and could tell from EGT that the front two cylinders were not firing. After almost ten minutes, the front two took off. She started fine the rest of the day and the next day.

Have done that with the cold start motor/solenoid and after 20 minutes it's warm to the touch but no move.

Summerville, Oregon....were at the moment, it's a white out!


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## thepumpguysc (Jan 25, 2015)

You STILL have a fuel supply problem.. hook an electric supply pump to the system & I think you'll fix your problem..
Be careful when choosing a pump.. you don't want anything over 10-12 psi..
BUT not less than 5 psi..
TO BAD on the snow.. we've have 80* for the last 8 days.. got the garden planted.. the front fence painted./ cars washed & waxed.. dogs washed.. grass cut.. I could go on & on..


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## Keshka Kotera (Dec 27, 2017)

I will try that!


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## Keshka Kotera (Dec 27, 2017)

Update.......I "think" I am getting close. I did hook up an electric primary pump. Know the injector pump is getting fuel. Made sure the cut off solenoid is functioning correctly. Pulled an injector and the line to it and put both back off to the side of the tracktor. As suspected, no fuel, no spray, not even wet.

Tried several way to check injector pressure. I do have a gauge that goes to 6000 psi but no fittings in my extensive junk pile nor anything I could purchase locally. Called all around and min $2500 to rebuild injector pump and close to $8k for new.

Ah calls bull#hit. Fine! I pulled the injector pump and took it apart. Ah hah! full of some sort of brown tar coating everything. Off to parts house, bought a gallon can of soak it carb cleaner and dumped parts in that overnight. Next morning...clean, clean and more clean. Then, knowing how uber critical diesel systems are about TINY particles, I assembled it.

Still no workie. Heard about a semi local wizard about 60 miles away. Went to see the wizard. Wizard was impressed with what I had done but also notice I had installed the internal primary gear pump back plate 180 degrees out. Well hell 50/50 chance right and with no docs from the likes of Bosch whom keep them pretty well hidden (A-holes!). Bought a complete seal kit from Wizard and we tested the injector I had out as well. It was not doing well either. 

Back home. Break down pump again to install new seals from kit and also check for crud in a couple of places Wizard said it hides. Carefully assemble pump again. 

Removed ALL injectors, disassembly keeping parts together in case of possible custom assembly of such high tolerance parts and possible wear induced mating. dunk in carb clean bucked overnight and re-assemble injectors today. 

tomorrow, put all back in tractor.....results to follow

P.S. Looks like all caused by moisture/condensation over time and not running tractor often enough to keep clear. And thanks where credit is due to the wizard aka Lorin Wentland of Wentland diesel in Milton-Freewater, Oregon.


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## thepumpguysc (Jan 25, 2015)

Wow.. that's a LONG way to go, {ALOT of work} for "maybe" results..
WHY didn't you just drop it off at the shop while you had it apart? AND were at the shop?
So your saying you put the hole in the supply pump backing plate to the bottom instead of the top?? What about the liner & blades UNDER the plate?? both can be assembled 180*.. how about the cam plate pin relationship to the driveshaft?? & what about the metering sleeve orientation on the pumping plunger?? OH & how about the advance piston?? that baby will go in 4 different ways..
Is your drive shaft KEYED?? or is it a keyless drive?? IF its keyless, the timing has to be set w/ a dial indicator & locked before installation..
I'm just trying to save you some heartache.. Good luck w/ your rebuild, I really hope it works out for ya..


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