7520 runs on

[flatrockfarm]

Hi

I have a friend with a 7520 that is running on after the key is shut off. It only idles, it won't rev.

Local dealer has replaced the fuel shutoff solenoid and then the entire injection pump trying to correct the problem. They have adjusted timing and replaced some relays. They are getting little support from Mahindra. Tractor still runs on intermittently after shutdown.

My friend has said that it seems he can get it to shut down by revving the tractor hard imediately before he turns the key.

Any Ideas?

 

[civesnedfield]

Hi

I have a friend with a 7520 that is running on after the key is shut off. It only idles, it won't rev.

Local dealer has replaced the fuel shutoff solenoid and then the entire injection pump trying to correct the problem. They have adjusted timing and replaced some relays. They are getting little support from Mahindra. Tractor still runs on intermittently after shutdown.

My friend has said that it seems he can get it to shut down by revving the tractor hard imediately before he turns the key.

Any Ideas?

No idea what is causing that, but I can tell you exactly what Mahindra's response is. "Read your warranty. Tires, batteries, and injector pumps are warrantied by their individual manufacturers. NOT MAHINDRA "

 

[bindian]

Hi

I have a friend with a 7520 that is running on after the key is shut off. It only idles, it won't rev.

Local dealer has replaced the fuel shutoff solenoid and then the entire injection pump trying to correct the problem. They have adjusted timing and replaced some relays. They are getting little support from Mahindra. Tractor still runs on intermittently after shutdown.

My friend has said that it seems he can get it to shut down by revving the tractor hard imediately before he turns the key.

Any Ideas?

I will check my 6520's owners manual wiring diagram when I get home this morning. I don't think it is a fuel related problem. I am thinking more of an ignition switch (circuit) having an internal defect and keeping your fuel solenoid partially on. I am thinking the fuel solenoid is partically open when the key is in accessory position. Can you find out what relays they replaced? Is he getting any smoke when starting up? :confused2:
hugs, Brandi

 

[bindian]

Without knowing what all relays were replaced, I would say check and make sure the engine shut-off system (circuit) has a good ground,especially at the engine shutoff (fuel) solenoid. After looking at the wiring diagram and going with the assumption that all the parts that were installed for troubleshooting were good............and if all the wires are good, I would say it is a bad key switch, or worse...a short in the instrument cluster itself.
Kinda hard to figure out here. It is kind like troubleshooting an aircraft that is flying all day. Each station with maintenance tries something and most often.......not everything gets recorded and you have to assume that the troubleshooting was done wrong before and you start all over.:confused2::confused2:
hugs, Brandi

 

[LAWALLSTRACTOR]

It sounds to me like there is some trash under the fuel shut off solonoid, stopping it from completely closing. It seems strange they wouldn't have found that problem by now, but that sounds like the problem to me.

 

[bindian]

It sounds to me like there is some trash under the fuel shut off solonoid, stopping it from completely closing. It seems strange they wouldn't have found that problem by now, but that sounds like the problem to me.

Galen,
That would do it, but he said they changed the solenoid. Is the shutoff valve seperate from the solenoid?
Our airlines have them as one unit, but you can change the actuator (solenoid) separately from the valve.
hugs, Brandi

 

[flatrockfarm]

Thanks for the ideas.

As far as the warranty goes, the complaint of lack of support was from the dealer and without knowing what the problem is and therefore not knowing who has a responsibility to fix it. Until they understand what is wrong, they should be getting support. The dealer has been very helpful. They also sell other brands of tractors and equipment, so when they say they are not being well supported by Mahindra, I believe them.

Bindian-He was having a smoke issue on startup for a while, but my understanding was that somewhere in the three or four times he had it back to the dealer this issue was resolved. The running on issue remains. Possible link here?

The possibility of the shut-off solenoid being partially held open is a good one. The dealer has cleaned and replaced the solenoid so many times with no change that I feel confident that it is not gunk in the plunger. I have had him remove the wire from the solenoid while it is running on and it has continued to run, but possibly the plunger was already stuck at this point. Maybe a temporary toggle-switch is in order for diagnostic purposes.

Thank you for your input.

 

[SPYDERLK]

Oil getting into the intake tract ... probably via the turbo seal...? Is the air filter clean?
larry

 

[flatrockfarm]

spydrlk-

That is a real possibility. I own a 6500 and keep forgetting that the 7520 has a turbo. That would explain the inability to rev while running on, intermittent nature of the problem, and inability to diagnose a fuel/electrical issue.

Thanks.

 

[LAWALLSTRACTOR]

Oil getting into the intake tract ... probably via the turbo seal...? Is the air filter clean?
larry

Larry,
Are you suggesting that the engine is running on engine lubrication oil that is leaking into the intake? If this is a possibility I would like to learn more about it, and if this is what is happening I would think that his oil level would be dropping.

Brandi,
I have seen this happen before and I have used a Qtip to reach down into the injector pump, when the solonoid is removed, to clean trash from the surface of the seat.