Tractor Will Not Start

[Dave M7040]

Each glow plug will read low ohms, like 10 or less.
Be sure to disconnect each one from the buss bar that joins them and read from connection to ground.
Also if you cycle the plugs each one should feel warm to touch for a very basic go/no go test.

I am wondering if the GP resistance value is a lot closer to 1 ohm.

Are you following the fuel system bleeding steps in the Owner's Manual?

Not bleeding properly is a major reason for a no start condition.

Is the glow indicator on the dash appear to be working properly?

Do you have the free workshop manual available here?

Download Cub Cadet 7 Service Manual | ManualsLib

You can also find an Owners' Manual on the same site.

All engine timing marks are on the front of the engine none on the flywheel.

Dave M7040

 

[bill18163]

I think I did read somewhere where the resistance should be one ohm or a small bit more on the GP's. Yes we did bleed according to the sequence in the manual. Interesting that you mention the glow indicator on the dash. My neighbor showed me how it comes on but goes out very quickly. There is some kind of timer module below the dash I think. I wonder what the specs are on that. Like how long should it stay on. The garage is warm when we are working but not hot. Maybe 65 degrees. But when I watched it when he turned the key it stayed on about five seconds and went out. I'll try to convince him to pull those GP's and test them before he starts tearing the engine apart. He is getting very upset and worked up over this and he has to go to work every day. I'm retired so I have more time than he does to do research on this problem. Thanks Dave M7040 for the info on the timing marks. It bothered me that there are no timing marks on the flywheel. You put my mind at ease on that issue.

 

[Dave M7040]

I think I did read somewhere where the resistance should be one ohm or a small bit more on the GP's. Yes we did bleed according to the sequence in the manual. Interesting that you mention the glow indicator on the dash. My neighbor showed me how it comes on but goes out very quickly. There is some kind of timer module below the dash I think. I wonder what the specs are on that. Like how long should it stay on. The garage is warm when we are working but not hot. Maybe 65 degrees. But when I watched it when he turned the key it stayed on about five seconds and went out. I'll try to convince him to pull those GP's and test them before he starts tearing the engine apart. He is getting very upset and worked up over this and he has to go to work every day. I'm retired so I have more time than he does to do research on this problem. Thanks Dave M7040 for the info on the timing marks. It bothered me that there are no timing marks on the flywheel. You put my mind at ease on that issue.

I quickly looked at the Cub Cadet 7600 series wiring diagram re the GP indicator. Is there any chance this is a glowing coil of wire and not a light bulb?

Typically the GP's are designed for 10.5 volts. DO NOT go testing them in open air. They could blow up in your face as they rely on the heavy metal of the head to moderate their temp rise. If you must, clamp them in a heavy vice as a heat sink.

Again typically, the key switch in the pre heat position sends power to the GP's through the glow indicator which is actually a resistor in series with the GP's and lowers the voltage down from a nominal 12 volts. When the key switch is turned to START, the glow indicator is bypassed and power flows to the GP's while the engine is cranking. The reason for the bypass is that the starter is drawing down the battery voltage.

I am not saying there is no timer module just that I do not see it in the wiring diagram I found.

Another thing to try is to blow warm air from a heat gun or hair dryer into the intake after the filter.

Dave M7040

 

[dodge man]

If it had good compression and it’s getting fuel it seems to me 65 is warm enough to start without glow plugs.

 

[PILOON]

I am wondering if the GP resistance value is a lot closer to 1 ohm.


Dave M7040

Always possible as there are some that are 'fast glow', so to speak.
But to get heat resistance is needed and a 'near short' will do that.
So fast glow would need to be hot and fast ergo low resistance.

Fastest, easiest is finger contact on each plug after a cycle (on cold engine). Not scientifically accurate but good enough.

 

[3gunr]

I have the same tractor with the same issue. If i press the throttle pedal to the floor it will start . i have also when it was very cold , gave a tiny shot off starting fluid and it starts right up.

 

[George2615]

I think I did read somewhere where the resistance should be one ohm or a small bit more on the GP's. Yes we did bleed according to the sequence in the manual. Interesting that you mention the glow indicator on the dash. My neighbor showed me how it comes on but goes out very quickly. There is some kind of timer module below the dash I think. I wonder what the specs are on that. Like how long should it stay on. The garage is warm when we are working but not hot. Maybe 65 degrees. But when I watched it when he turned the key it stayed on about five seconds and went out. I'll try to convince him to pull those GP's and test them before he starts tearing the engine apart. He is getting very upset and worked up over this and he has to go to work every day. I'm retired so I have more time than he does to do research on this problem. Thanks Dave M7040 for the info on the timing marks. It bothered me that there are no timing marks on the flywheel. You put my mind at ease on that issue.

I agree to test each glow plug resistance first then check if voltage is getting to them when the GP light is on. That Cub has the same Mitsubishi engine that was in my 2004 Mahindra 2615. I replaced 3 sets of plugs over the years before I found there was an upgrade kit. The kit included new plugs (different than orig) and a new timer (longer cycle time). No starting problems after installing the kit. The original plugs had a habit of either shorting out or going open and the timer cycle time was too short. The kit addressed those problems.

 

[PILOON]

On one diesel vehicle the timer was very $$.

I simply installed a momentary push button and counted thousand and one, two etc., worked like that for 3-4 years.
If no success on first count I'd do another adding more seconds.

Knew on guy that simply pinched a pair of wires under his dash!

 

[bill18163]

George2615,
Do you have the information on that upgrade kit?

 

[George2615]

George2615,
Do you have the information on that upgrade kit?

No I don't. Its been 8 years since I got it and I've since sold that tractor. All Mahindra dealers were notified of the upgrade but everytime I went to get new plugs the dealer never mentioned the upgrade. I think he thought if he sold me the upgrade kit I'd stop coming back every couple years and spend over $100 for new plugs. I actually found out about the upgrade from a dealer in Batavia, NY who is/was a member here and bought it from him.
There is a thread on this is the Mahindra section. Found a couple links.

https://www.tractorbynet.com/forums...ng/389990-yet-another-mahindra-glow-plug.html
https://www.tractorbynet.com/forums.../369889-2015hst-mahindra-glow-plug-issue.html
https://www.tractorbynet.com/forums...ting/389741-mahindra-2615-gear-glow-plug.html
This link has the members name who I bought from. Sorry, but I don't know if he's still in business. (LawallsTractor)
https://www.tractorbynet.com/forums...5095-installing-glow-plug-conversion-kit.html

 

[Industrial Toys]

If it's puffing white smoke, it's probably getting fuel, just not enough heat.

Be carefull. It's easy to ruin glow plugs. I did that last year. Tried to disconnect them for testing and turned the whole rods, ruining them. Having a DC clamp meter can be helpful in troubleshooting.

 

[bill18163]

Here's an update. We pulled the injection pump housing and disassembled the three pumps. Not much wrong there. We put them back together and pulled the injectors. Same there. We took them apart to check them out and nothing looked out of the ordinary. The ends of the injectors had a lot of black material on them. We cleaned that up. We took the steel injector fuel supply tubes and hung them out away from the engine and connected the injectors to the tubes and cranked the engine. We got a nice spray out of each injector. One was not quite as good as the other two but I would say it is OK. So much for the fuel supply system. I think we can put fuel behind us now. I had suggested checking valve clearances and when I came over another morning my neighbor had pulled the valve cover and was checking clearances. He had some gaps of almost .040". The spec is .010". We decided to pull the head and check out the valves. All the valves were in good shape but we did take them out of the head to get a good look at them. All were worn evenly and looked good except for the carbon. Never saw so much carbon. All the valves were covered with it. Also, the head was full of carbon at the fuel intake ports. A couple of them were half way blocked. There was a tremendous amount of black goo deposited all throughout the head also. We are currently cleaning everything up and waiting for gaskets to arrive. I am not sure if it was needed but we are also putting in new valve guide seals. I thought maybe too much oil might be getting past the seals and into the combustion chambers. They were not that expensive. One of the most significant things that came up though was related to me while I was talking to my sister-in-laws husband. He farms about 400 acres and of course he is familiar with tractors and diesel fuel. He asked me if my neighbor had changed the fuel filter while working on the tractor. I said yes that he had just changed it. He asked me if I had seen it but I had not. I got on the phone and asked my neighbor what it looked like when he replaced it and he said it was all black and full of goo. So now we are thinking that we have an algae problem and that fits with the way that head was all clogged up with that oily looking mess in it. So, we are waiting for gaskets and cleaning things up. I ordered some stuff called Biobor JF Microbicide that I read about on the web and am hoping that will take care of the fuel problem. Once we get it back together I'll post and tell what happened.

 

[bill18163]

I noticed that when I was scraping the head gasket off the block that two of the water jacket holes in the block were covered by the gasket. There were perforation marks in the gasket right over these holes into the water jacket that indicated that these were punch outs that should have been removed prior to the gasket being assembled. That's my take. It's my neighbor's tractor. He seems to think that he read somewhere that for some applications water jacket holes will be blocked off by the head gasket for a reason. Namely for the redirection of cooling fluid to more needed areas of the head and block. We are currently waiting for all the gaskets so we can reassemble the head and other parts. He bought the tractor second hand about 12 yrs ago. We are guessing that the tractor was built around yr 2000. So, has the tractor head gasket been replaced by the first owner or was it assembled at the factory that way? We don't know of course. My feeling is that none of the water jacket holes in the head or block should be blocked off unless the gasket is solid in the area of the individual holes and is not a perforated punch out that is still attached to the gasket. Would anyone care to comment on this?

 

[LouNY]

Did the head have the corresponding holes in it.
Often times heads will work with multiple blocks and blocks will work with different heads.

 

[bill18163]

I'll have to check that out. Right off hand I would bet that the head has the matching holes that mate up with the block. Let's just say that it does. What would be your reply be then?

 

[LouNY]

I would likely open the gasket holes

 

[bill18163]

LouNY,
I checked that head today and there is no matching water jacket hole in the head that mates up with the block. Thanks for the prompt to go check it out.

 

[bill18163]

We still cannot get this tractor started. We have been trying to get gaskets over the last number of weeks and it is unbelievable how hard it is to find them. We did get the main one though which is the head gasket. We bought gasket material for the rest of them and made our own. So let's go on to the problem and I will tell where we are right now. If you reference the beginning of this post you will notice that my neighbor was running this tractor along and it came to a sudden stop with a clanking noise and the engine stopped. We took care of that by repairing the clutch arrangement. A bolt had come loose in one of the clutch bearing release arms. We are assuming that is where all the noise came from when the tractor stopped running. The bolt looked liked it had been crunched up when we found it in the bottom of the clutch housing. So we put the tractor back together and it will not start. You would think that if the clutch was the only problem then when we fixed the clutch it should start. Right? Because it was running before. Why does it not start now? We checked electrical items related to fuel. Namely the stop solenoid and the glow plugs. Both are working as they should. My neighbor disassembled the fuel pump and checked it all out. He said he didn't see anything out of the ordinary. We cranked the engine with the fuel delivery tubes not connected. So all we were looking at was the top of the three injection pumps with no fuel lines connected. We wanted to see if fuel was being pumped. Each pump would pump a stream of fuel about maybe an inch high. We pulled the injectors out and disassembled them and checked them out. Couldn't see anything wrong. We swiveled the three injector supply tubes outward away from the engine and connected the injectors to the tubes and cranked the engine. Each injector was throwing a fine mist of fuel. As far as we could know this looked OK. So after thinking about this and putting our heads together we wondered about injection timing. Why would injection timing change? We don't know. We just don't know what else to check. However, when we followed the procedure in the manual to check the injection timing we ran into an anomaly. The manual says to remove the delivery valve and spring from the #1 pump and put the delivery valve holder back on with those two parts not in. Then put the delivery pipe back on the #1 pump and turn the ignition key on so that fuel runs out of the pipe. Then turn the crank shaft with a socket wrench on the crank pulley nut slowly clockwise until the fuel coming out of the delivery pipe stops. The injection timing is just when the fuel stops coming out per the manual. The timing marks on the pully should line up with the counter mark on the gear case at this point. We did all this and all the procedures worked per the manual as we worked through them except one thing. The fuel never stopped flowing out of the pipe as the crank shaft was being turned. It should have stopped in the area of the timing mark on the crank pully. So what could be wrong here? I have attached the page from the manual that shows the procedure. I forgot to mention that when we had the head off we found a lot of carbon in there and a lot of black stuff that we later determined was an algae problem in the fuel. The fuel filter was full of the black stuff so we changed it. We also bought some fuel treatment and put it in the fuel tank.

 

[LouNY]

Did the fuel flow slow down as it came close to the timing marks?

 

[bill18163]

No it did not slow down. The stream of fuel just ran constantly.