JD 855 Hard to Start??? Help Please!!!

[rox5488]

Hello Everyone,

I am in need of any advice on a hard starting John Deere 855 Compact Tractor. I will outline the problem and things I have tried so far and hopefully someone out there will be able to tell me anything else to try.

When the tractor is cold (1st start of the day etc) it is on the rough side to get started. I suppose I will mention that our temps here are on average about 40ish deg right now. maybe 45 where the tractor is kept. then then of course colder at times as well. So I haven"t been able to see how it does when its in the 60"s and up either. Anyway...

I hop on and crank it over and what I have to do is actually crank the engine for about 10 to 15 seconds. (hold the key over) it is usually going enough by then that it will chug and chug like a choo choo train for the next minute or so until a time when it finally level"s off and smooths out to a nice idle. During the chugging time it is rattling and shaking pretty bad... Like something isn"t quite working right in there... not getting enough fuel or something. This seems to be the case no matter where the throttle lever is at position wise either. When it is doing its' "chugging" the RPM's are about 500 or so and I can push the lever up to full throttle but it still sits there and chugs until it seems to level off some.

It worries me the amount of shaking until the minute or so passes and it levels out. The tractor has 900 hrs on it.

Other item the smoke is quite black on startup which is fairly normal I guess. No white or blue smoke that might lean me toward a compression problem but once again I do not know for sure. Possibly that is it!

I have changed the oil, filter, and fuel filter so far. I have put seafoam into the engine to clean out the injectors etc as well.

I have also checked to make sure the fuel pump is working and it seems fine as well. I am going to test the flow but I am not able to test the pressure because I do not have the correct gauge to do that.

I have also tested the preheat grid on the air intake, it is getting voltage and does warm up. Not I am not sure how warm it should get and I have not taken off the 90 Deg elbow to check it out to verify the whole grid was working but it does seem to be OK.

Finally I checked the fuel selinoid shut off and it does release and engage as I believe it should. Possibly needs an adjust ment or something though?

Could anyone tell me what I should try next?

once the tractor idle levels out etc it runs well. Seems strong and really only loses power when I literally floor the pedal going uphill. It then of course bogs the engine down. Otherwise it seems OK. Also when starting it after warm there is no trouble either.

What I feel is weird is I beleive it actually started better BEFORE I changed the filters etc. But I am not 100% sure that is true. I didn"t run it too many times prior to doing that maintenance.

Thanks for any suggestions as what I can try.

 

[plowrup]

Which type of Fuel are you using? Have you put in Diesel Fuel Conditioner? Does it run normally AFTER start up? Are you using your pre-heater first? For how long? Have you made sure it is operational? What weight Engine Oil are you using? Do you have regular Hy gard or Lo-Vis in the Hydraulic System? Are you certain that all of your Hydraulic levers are in the Neutral position?

We are starting to see some problems with the reformulated Diesel Fuel-this problem is primarily in the new Tier II Engines, and it has to do with the cetane rating (like the octane rating in Gasoline, it refers to the amount of BTU's)-more and more we have had some issues here-which Fuel are you running? On road or off-road (is it colored)? Have you had any problems with your Fuel at all (clogged Fuel Filters in a short time?) Is the Air Intake free of any obstructions? Lots to talk about here-

 

[rox5488]

Hi Plowup

Which type of Fuel are you using?
Just standard ON-road Fuel. I don't recall the Cetane rating.

I have no used any type of conditioner to this point.

After it starts yes it runs normal and seems to have good power etc. It only seems to have trouble on the first start when cold.

I did check the preheat (its an air intake NiCad grid, no glowplugs). It seems to be working although I am going to recheck the connections when I get home and clean them all to be sure it is getting the correct amount of current etc.

Oil is regular Hygard.

I saw on another power that there to 2 fill locations on this model. The top on valve cover and down on the lower right side. I filled thru the top valve cover but I have read where you are to fill thru the other one. I have no idea how that would effect the starting though if at all.

all levers are in neutral to my knowledge but I can doublt check.

Air intake is good to my knowledge I did take it all apart for inspection.

The diesel fuel like I said is just standard On road fuel. i don't know if they were still using the winter blend but I am fairly sure they were.

Thanks so far! I'll update after I check those connectors and as well as checking/bleeding the lines at the injectors.

Does anyone have any proceedure for checking the NiCad Grid? Just take it off for inspection I suppose? I don't know what the temp of it should be...

 

[plowrup]

I do wish to say that all Diesel engines will smoke upon start up, and I have had new 855's (wow, I have been doing this TOO LONG!)that would exhibit what you are referring to, but that usually was when the Preheat was NOT used, so I would also check the Voltage and condition of the screen-

As I recall, your machine will self-prime, so bleeding the Injectors may not be needed. Cetane has to be checked by someone that has the equipment, and, due to the age of your machine, I don't think yours will be as sensitive to cetane-just a thought.

I assume this unit is outside-that Hygard is like molasses in the cold (that''s why we sometimes use Lo-Vis)-regarding the Preheat screen, if the Voltage is there, I don't recall having to replace the element-ever-maybe someone out there has-let me know, I'll help if I can-remember, you are getting what you are paying for /forums/images/graemlins/smile.gif

 

[BigEddy]

My 855 does the same thing as yours - if it is cold - 0 Farenheit or below. It does not do it above that temperature.

I have always figured that I was getting incomplete combustion - hence the knocking and shaking and the independence from throttle position. Once it starts firing properly on all cylinders, it settles out. Varies based on temperature - colder = longer.

I don't have a block heater - think that might improve things. I always use the pre-heat till the light goes off. So I can't say if it would be worse without. If I remember - I'll try next cold morning.

 

[rox5488]

Guys thanks for the info to this point.

Eddy I am seriously thinking of getting the block heater to help, I just wanted to make sure it wasn't something else first.

From what you say it might be common with these tractors??

Mine just sits there about 1 minute and chugs around and then it eventually pulls up and levels off into a good idle. As mentioned it runs fine after that until it is off for awhile.

I am going to bleed out the system tonight to make sure no air and such too.

And clean up the connections on the NiCad Screen. I didn't take it apart yet and really didn't want to. It is getting about 10 Volts I believe but will double check.

Thanks again so far.

 

[rox5488]

Evening all!

Well tonight I was checking things out further. I am not positive but I may have found a problem. I cleaned the controller on the preheat and reinserted it.

I then pulled the bolts that connect the air intake line into the preheat grid and manifold. I also removed and cleaned the connection to the preheat grid.

SO with the intake tube off I turned the key over to preheat the grid. The voltage was there (12 volts) I assume that is correct anyway... It was there at both ends and there was continuity thru the grid.

The problem though is it never heated up at all. which i found quite odd. I assumed if there was voltage the grid would heat. at least some. This one did not heat at all. Has anyone seen anything like this? does anyone know what resistence thru that grid should be? I could check that yet I suppose... But I am thinking I should replace that part? IT definatly isn't heating in preheat mode. (or does it ONLY heat while the engine is cranking, but that doesn't make much sense to preheat...)

After so long the circuit did cut out as well. and there was no voltage to the grid then. There was an audible click at that point. Then I had to let it sit a bit. I assumed that grid would get much like a cigarette Lighter and be orange and hot to the touch at least. I could hold it and touch it with my finger after preheat and it was 'dead' so to speak.

IF anyone could let me know their thoughts If I should replace that controller and the grid or just one etc?

Thanks guys.

 

[BGL990]

<font color="blue">The voltage was there (12 volts) I assume that is correct anyway... It was there at both ends and there was continuity thru the grid. </font>

What exactly do you mean by "it was there at both ends"? I'm not sure exactly what connections there are to the preheater, but I assume there is a + power connection and a ground connection. If you measured the same voltage at both points, then there are ZERO volts across the heater and it won't heat up. Since you measured 12V (referenced to the engine block or tractor frame I assume), power to the heater is probably OK, but it sounds like a bad ground connection.

The resistance through the heater should be very close to zero ohms - almost a dead short to most ohmmeters.

Hope this helps!
/forums/images/graemlins/tongue.gif

 

[rox5488]

Hi Brad

Yes I assume you are right on this. I did measure the 12 volts on the input and on the other side of the grid where it connects. Which your probabaly right there wouldn't be a good ground. I am unsure how the unit should be grounded properly. Which it is just thru being hooked up inline or if there is supposed to be a wire grounding the other side. There was no wire which I assume means it is ground thru the bolt connection...

Maybe that also explains why when I had it apart it wouldn't heat up properly. Hmmm. A bit disheartening as I thought I was on to something there and now I'm not so sure I was.

Maybe someone out there could tell me how that grid is supposed to work and be grounded. The housing almost feels aluminum and in the intake that connects to the air filter feels almost plastic so I'm not sure how it is to be grounded.

 

[plowrup]

I was contemplating your concerns and went to DTAC (Dealer Technical Assistance Center)-here is one Solution:

COMPLAINT:
ENGINE TAKES A LONG TIME (15-20 SECONDS) TO START, EMITS WHITE SMOKE AT
START UP AND OCCASIONALLY DURING RUNNING. POWER IS LOW AND WHILE ENGINE
RUNS SMOOTH, IT DOES NOT HAVE DIESEL "CLATTER". COMPRESSION IS LOW.

PROBLEM:
- SOLENOID SHUT-OFF (IF EQUIPPED) IMPROPERLY ADJUSTED OR MALFUNCTIONS.
- VALVE LASH IS SET TOO TIGHT.
- FUEL SHUT-OFF LEVER BINDS IN GOVERNOR HOUSING.

SOLUTION:
1. CHECK FUEL SHUT-OFF SOLENOID AND LINKAGE FOR:
- PROPER VOLTAGE TO OPERATE PULL IN AND HOLD IN WINDINGS OF
SOLENOID.
- ADJUSTMENT OF SOLENOID LINKAGE. MUST PULL SHUT-OFF LEVER TO FULL
ON POSITION (WITH A LITTLE FREE TRAVEL LEFT). SEE APPROPRIATE
TECHNICAL MANUAL FOR ADJUSTMENT PROCEDURE.

2. CHECK CRANKING SPEED.
- 200 RPM IS MINIMUM TO START HORICON BUILT TRACTORS WITH YANMAR
ENGINES.
- 250-300 RPM IS NORMAL WARM WEATHER CRANKING SPEED (30W OIL).
- 225-250 RPM WHEN COLD AT -15 DEGREES F (-25 DEGREES C) (5W30 OIL).

3. A. IF LOW HOURS, SET VALVE LASH.
B. IF HIGH HOURS, IT MAY BE NECESSARY TO RECONDITION VALVES AND
SEATS TO TOTALLY CORRECT. SET VALVE LASH. SEE APPROPRIATE
TECHNICAL MANUAL FOR ADJUSTMENT PROCEDURE.

4. RECHECK COMPRESSION. IF LOW, OTHER CAUSES EXIST.

I've got a few appointments with Customer's (and my JD Rep) today, but if I get some time I'll look and see what the Book says about grounding of the Element-my gut tells me that one of the previous posts is correct-typically since it is a one wire Element, it must be grounded, which would probably occur through the unit being bolted to the Intake-