DK40SE HST No start - fuel problem? electrical?

[tabacman]

Ok solenoid and relays for fuel shutoff confirmed functioning. Took it out and watched with my own eyes. Still no light off.

I put the multimeter on what i think are the tops of glow plugs and i get no voltage when key is on.

I notice the trouble shooting chart in the book says - no cold eng start is the timer relay.

I shot the key switch up w wd40 - doesnt appear to have changed situation.

Whats best way to check that glow relay?

 

[k0ua]

Ok solenoid and relays for fuel shutoff confirmed functioning. Took it out and watched with my own eyes. Still no light off.

I put the multimeter on what i think are the tops of glow plugs and i get no voltage when key is on.

I notice the trouble shooting chart in the book says - no cold eng start is the timer relay.

I shot the key switch up w wd40 - doesnt appear to have changed situation.

Whats best way to check that glow relay?

Keep in mind the glow timer is on for a few seconds, but it also "post glows" after start about 15 seconds. But if you don't have any voltage on the glow plug buss, then either the relay coil is not energized by the timer circuit in the module or the relay is defective. I would measure for voltage on the coil contacts and also the "make" contacts.

BUT.. If the weather is warm, I am doubting the pre-heat system not working at all would cause it not to start. Isn't it warm in Indiana now? I would think the tractor might stutter and stammer a little but I would think it would still start at these temps.

 

[Billrog]

Exchange the relay with one of the other ones and see if it makes a dif.

 

[k0ua]

Exchange the relay with one of the other ones and see if it makes a dif.

Well, the glow plug relay is a 70 amp heavy duty relay. Just make the voltage measurements to see if the coil is being energized, and if so then see if it pulls up and making contact from the 12 volt buss to send the power to the glow plugs.. simple measurements with a VOM.

 

[tabacman]

Well, the glow plug relay is a 70 amp heavy duty relay. Just make the voltage measurements to see if the coil is being energized, and if so then see if it pulls up and making contact from the 12 volt buss to send the power to the glow plugs.. simple measurements with a VOM.

Can you clarify where to take measurements? Im a bad electrician...

 

[tabacman]

Well, the glow plug relay is a 70 amp heavy duty relay. Just make the voltage measurements to see if the coil is being energized, and if so then see if it pulls up and making contact from the 12 volt buss to send the power to the glow plugs.. simple measurements with a VOM.

Yes its plenty warm today 70-75

 

[ritcheyvs]

The key switch can get wonky (mine did) such that it works OK in the on/run position but gets intermittent in the crank position. If you can get a helper, make sure the stop solenoid does not "drop out" (lose hold power and extend) when you turn the key switch to crank (I doubt you could hear it extend with the starter cranking). Same for the glow plugs; ensure you have power to the bus bar on top of the plugs when you crank the engine as well as when the key is turned to "on".

If the starter (it cranks) , stop solenoid (it stays retracted) , and glow plugs (they are powered at least until after you crank) are all OK, those are the only electrical things that effect the engine starting and running.

The next thing I'd check is to see if fuel is reaching the injectors. Loosen one or more of the B-nuts (the nut-like thing that holds the pipe on the injector) and crank the engine. You should see a little fuel seep out when you crank.

I understand that the SE HST models have a manual fuel shutoff in the vicinity of the fuel filter. You might check that it isn't turned off.

You might make sure the fuel filter is full of fuel (no air). There is a bleeding procedure if there is air in the filter. You might check that the lift pump is working to deliver fuel to the big filter; there should be a manual lever you can use to operate this pump's diaphragm if is not already at the top of the cam lobe. But lift pumps usually fail in a way that the engine will idle but not rev. Still, a bad check valve in the lift pump could allow the main fuel filter to drain and introduce air into the system. The main point is that all air must be purged from the fuel system for the engine to start/run.

 

[Egon]

When cranking the engine do you get fuel delivery to the injectors?

 

[ritcheyvs]

Can you clarify where to take measurements? Im a bad electrician...

In this diagram, the glow plugs are number 11 and the bus bar is number 12. You can measure the voltage between any bare metal on the engine block (like a screw or nut) and any bare metal on the bus bar. A nut at one of the glow plugs is a good place. There is a wire that connects to the back end of the bus bar to provide the power; make sure it hasn't come off. The glow plugs will only be powered for a short time after the key is turned to "on". There is a timer (in the display unit) that turns on and then off the instrument panel "glow" light after 0-8 seconds (depending on engine temp) and then shuts down power to the plugs 15 sec later. The display unit supplies 12v to the glow relay coil to energize the glow plugs and zero volts to turn them off.

Some indirect-injection Diesel engines (like yours) will start on a warm day (like 75 degrees) without glow ... and some won't. So you do want to be sure your plugs are getting power.

 

[tabacman]

<img src="http://www.tractorbynet.com/forums/attachment.php?attachmentid=423179"/>

In this diagram, the glow plugs are number 11 and the bus bar is number 12. You can measure the voltage between any bare metal on the engine block (like a screw or nut) and any bare metal on the bus bar. A nut at one of the glow plugs is a good place. There is a wire that connects to the back end of the bus bar to provide the power; make sure it hasn't come off. The glow plugs will only be powered for a short time after the key is turned to "on". There is a timer (in the display unit) that turns on and then off the instrument panel "glow" light after 0-8 seconds (depending on engine temp) and then shuts down power to the plugs 15 sec later. The display unit supplies 12v to the glow relay coil to energize the glow plugs and zero volts to turn them off.

Some indirect-injection Diesel engines (like yours) will start on a warm day (like 75 degrees) without glow ... and some won't. So you do want to be sure your plugs are getting power.

Ok i get astream of fuel from mechanical pump up to filter bowl on cranking.
Havent checked lines out of injector pump yet.
I get no power on the glow plugs with key on. Indicator light works for glow plugs.
I will check fuel flow out of injector pump tomorrow.
Is the preheat relay the one that sends power to glow plugs?