Glow plugs

[SD70Ace]

One last thing, What controls the gp's? The PO said truck was a bear to start if not plugged in. Back from the IDI I used to have, hard start when cold, have to be plugged in, bad gp system,right. But the IDI GP system was easy. Anyways, Im about to pull the injectors out,replace the GPs. What controls them? Lots of computerized stuff under the hood.

 

[bbressler]

There is a glow plug controller -- just above and to the left of the fuel filter. It can be bad. You can test it by shorting out the big terminals and trying to start. There is an upgraded heavy duty unit a few of us have that will just about ensure you won't have relay problems any more...

The computer turns the GP's on based on readings from misc sensors..(EOT)

 

[Mike]

Ben has you pretty well covered, heres a pic with the GPR location labeled. If its not the GPR that is bad its very possible that you have weak or burnt glow plugs. You can ohm them out individaully, they are the outer pins on the VCH connector. Good plugs ohm around .2, bad plugs will be 1.0 or higher or an open plug will be 0 ohms.

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[BJS]

Anyways, Im about to pull the injectors out,replace the GPs.

please tell me you're pulling the injectors for some other reason other than to do the GP's if you're just working on the gp's then you do not need to touch the injectors.

 

[SD70Ace]

My O rings are leaking on my injectors. Thats why. Useing oil and oil is in my fuel lines and tanks. Wich wire on the relay turns it on and off. The purple wire? If it is, I'll enegeize it and if theres any amp draw. The truck cranks up fine in this hot Texas weather. But in 5 or so months, I'll need em.