Cold start issue, suspect glow plug cycle time.

[Fleg]

I'm having a problem starting my M1009 as the weather gets colder. I'm starting to suspect it has something to do with how long the glow plugs are trying to heat up. The length of time (as evident by the audible relay closing and the voltmeter dipping) for a cold start has never really changed from the dead of summer to now the beginning of fall. All the other diesel vehicles I've ever owned has taken considerably longer time to cycle the glow plugs when it's colder out but so far not my 1009.

What is actually controlling the time or possibly sensing glow plug temperature? Is that adjustable somehow? My glow plugs are staying on around 5 seconds. WHen I try to start it it acts like it wants to fire but just doesn't have the heat to do so. When I cycle the key a few times and let the plugs cycle it will start right up. They are recently replaced glow plugs that still ohm out fine. I also don't think the glow plug senor (the one that actually monitors coolant temp) is bad as when the engine is warm it starts fine and doesn't cycle the plugs. I really don't want to install a manual push button for the glow plugs.

 

[mistaken1]

Read this:

http://www.steelsoldiers.com/cucv/62477-gp-module-theory-operation.html

See if that does not help.

There is also this from the TM:

http://www.steelsoldiers.com/cucv/76543-wait-light-momentarily.html#post963623

 

[Fleg]

Read through the GP Theory and had some ideas to try, couldn't really test to see if anything worked until this morning. Problem still exists.

I believe my wait light is functioning properly, it's on for about 8 seconds or so but the glow plugs cycle faster, in the 5 second range.

The only thing I've found that I still suspect in the TM's is to replace the glow plug switch.

 

[Warthog]

When you changed the glowplugs, did you clean the connectors? Adjust the tightness?

And is the small orange wire at the glowplug relay on the post with the two LARGE orange wires? (the wiring diagrams are wrong in the TMs)

 

[Fleg]

Just tested the glow plugs (running out of ideas) and they measured open. Those things were brand new! Also, the firewall resistor measured 2.8 Ohms so I figure it's still good.

 

[mistaken1]

I had brand new wellmans from diesel rx go open in a week. (2 or 3 starts)