Help with diagnosing no start condition CK2510 - Solved! See post 8

[Everhard]

Hello everyone, looking for some thoughts...

Situation:
CK2510 has been a challenge to start - turns over with no attempt to fire and then randomly on a key turn it fires up perfectly. Then after operating, I can turn it off and on with no issues at all until then next day/week when I go back to use the tractor. (and it's cooled back down to ambient temps)

Things I tried:
Today I decided it's time to figure out what the issue is. First tried squirting wd40 into key switch. No difference.
Swapped relays. No difference.
Pulled the Shut-off solenoid out to see if it's working - didn't think that when I turned the key with the solenoid off (but still hooked up to the wiring harness) that the tractor would fire! And up it started...
This led me to scratch my head on how to turn it off for a moment! Lol... Ended up turning off the fuel at the fuel filter switch.
While previous test was run the solenoid plunger didn't move. So at this point I'm thinking the solenoid is dead.
Go to dealer grab a new solenoid, get back, put it on, test and no joy... Now I'm thinking okay I don't have fuel... Open bolt by where the 3 injectors come from, fuel pisses out. (Yes I had turned the fuel back on previously.) So I guess I've fuel....
Now I pull off the relays and fully test them. Confirm they function properly and within spec.
Then I test the harness where the relay's go - I test pin's 85-86 to see when the key is turned that the relay is activated. Confirm continuity when key is turned. (There's 2 relays, one for start one for glow circuit assuming my understanding is correct. Both operate as expected)
Now I test connector where hte solenoid attaches, again continuity - it's a 3 wire connection, my understanding ground, one hot live for continuous running and one for startup. One combination on key turn gives me continuity, the other gives me continuity without the key turned.
Now I wanted to rule out lack of fuel - so with the solenoid out I turned it over - this time I can see it's starting to show whisps of smoke and that tell-tale sign. So I'd say if I kept trying it would fire. Now I didn't go that far as I'd be back to having to shut it off by killing the fuel supply again!

So at this point I've run out of guesses!
Obviously it's not safety circuit issues as I will start. Relays confirmed good. Harness shows relays will be activated. What am I missing... I think I'll see if I can make up something to manually kill the engine so I can actaully fire it up without the solenoid and then turn it off without turning off the fuel supply. Then at least I can confirm it'll start.

Any ideas in the meantime?

Thanks!
E.

 

[Everhard]

Further update - pulled the shut-off solenoid out and then tried starting it up to make sure the fuel was actually flowing and it started up no problem at all. I rigged up a simple tool to allow me to manually shut it off without having to turn the fuel off. Tested that it would start which it did properly every time.
Put the shut-off solenoid back in place and it won't start...

E.

 

[Roadworthy]

If the tractor always starts when warm that may point to a glow plug issue. Do the glow plugs themselves actually get power when you attempt to start? Check with a meter at the glow plug. Are the glow plugs good? Sometimes they open, sometimes they short which would ground out the power to them. On some tractors fuel is allowed to flow when the solenoid has no power, it is only interrupted for a short period when you turn off the switch. Try to learn a bit more about how your electronics operate. The schematic may not tell the whole tale.

 

[Everhard]

It's definitely not a glow plug issue as it'll start perfectly if the shut-off solenoid is not installed. Even when it's cold - after letting the glow circuit run first of course. But if the shut-off solenoid is installed it makes no attempt to start.

E

 

[34Willys]

I think your tractor has a Safety Control Module under the seat. Fuel cut off solenoid hold open is one of it's many wonderful features. More computer BS on a non-ECM, EPA effed up tractor.

Patrick

 

[Everhard]

The model that followed after this version definitely has the safety module under the seat, I'm not sure that this one does? I guess I'll have to pull the seat off to find out which I've been trying to avoid doing! Lol.

 

[34Willys]

First time I took my seat off, I unbolted the whole assembly from the deck. Very heavy and awkward. Last time, I just removed 4 bolts and lifted the seat off the slide rails.
Slide the seat fully back and remove the rear 2 bolts, then slide seat fully forward and remove the 2 front bolts. Lift off the much lighter seat and back as a unit.
This will give you easy access to the area under the seat.
If you need to, the rails are also easy to remove from the air ride unit once you have the seat removed and they are attached with 2 bolts and 2 nuts.
I have an open station, so cab will be more difficult.

Patrick

 

[Everhard]

Problem resolved!
So my error in diagnosing was I thought I was testing the correct relay for the fuel shut-off soleniod, turns out I wasn't... As soon as I realized there were 2 more relays I hadn't accounted for I quickly found the one for the fuel shut-off solenoid and sure enough it was dead.
Replaced and tractor fires up perfectly. With the old fuel shut-off solenoid. So turns out it was just the relay. Well Now I've a spare solenoid if that ever fails on me.

For those with a CK2510 (Note mine is a 2014 model! They changed the engine in 2016, and while visually there aren't any obvious differences I can't comment if they added a safety control module at some point or if that only appeared on the CX2510 in 2021.)
... Relay for the fuel shut-off solenoid is located behind the vertical cover below the steering wheel on the left side. You will see 2 relays, fortunately it's the lower of the 2. I believe the upper one will be the timer relay.
The other 2 relays are in the engine compartment on the firewall, on the right side. One is the start relay and the other is the glow circuit relay.

I don't have a shop manual for the CK2510 unfortunately but I do have the CK20s manual and while the engine is different I think the tractors are otherwise fundamentally the same. The electrical system seems to be the same other than for the minor location differences.

Thanks everyone for your thoughts. Hope this helps the next person!
E.

 

[kozal01]

Glad you figured this out, Ive been following along as I have the CX. No issues like this yet but now I have something to keep in mind if I do. Great diagnostic work!

 

[dodge man]

Well you screwed up when you changed the title of your thread, now I don’t get to see how many more posts accumulate that don’t bother to notice you solved the problem.