cranks but won't start

[thtrev2001]

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My 85 M1009 has run great for the last few months. It sat for two days and now won't start, it cranks but won't fire off. I checked the TM's and followed the steps. I have 0 volts on the bottom of the relay, with the key off, 25 with the key on. I checked all of the glow plugs and have 0 ohms on each. So is it possible that all of the glow plugs went bad at once? Am I missing something? I have read other threads on here and poured over the TM's. I'm not a mechanic or electrician, so I have limited knowledge. Any suggestions. zThanks

 

[Warthog]

With zero ohms, then yes, all your plugs are bad.

Read up on the resistor bypass and it will expaing what happened.

First one goes bad, then another and finaly all of them.

 

[mudman]

I just went though this also. Warthog is right 0 ohms means no good. if one goes bad then that extra voltage goes to the next one, and if that blows then the next and so on down the line untill the last one gets all the voltage. So to say they all went bad at the same time...I doubt it. Also make sure you're solonoid is working. short the blue wire to ground and see if it clacks and passes voltage. All parts are easy to get at cucv electric with no shipping at this time. John is a good dude to deal with. good luck.

 

[GPrez]

I had a similar issue a couple years ago. I replaced all the plugs and they went bad again almost immediately. Before I proceeded with the next set I checked everything and sure enough the glow plugs were staying energized which fouled them quick. I bypassed everything and manually energize them with a momentary switch on the dash now. Best thing I ever did.

 

[thtrev2001]

another question, so is it possible to start and run the truck with only a few working glow plugs? Is it possible that only a few were working and then the last 2 or so went bad, so now it won't start. BTW I did open the valve on the fuel filter and its getting plenty of fuel.

 

[GPrez]

another question, so is it possible to start and run the truck with only a few working glow plugs? Is it possible that only a few were working and then the last 2 or so went bad, so now it won't start. BTW I did open the valve on the fuel filter and its getting plenty of fuel.

Unlikely without doing a lot of cranking. Once one or two go bad it becomes difficult to start even in warm weather.

 

[cpf240]

another question, so is it possible to start and run the truck with only a few working glow plugs? Is it possible that only a few were working and then the last 2 or so went bad, so now it won't start. BTW I did open the valve on the fuel filter and its getting plenty of fuel.

Mine has been starting fine on 6 working GPs. A bit rough at first when cold, but she always starts on the first go-round. Though I'm in SoCal, so cold is a relative term. I do use the half-pedal for the fast idle on the colder days.

 

[mudman]

another question, so is it possible to start and run the truck with only a few working glow plugs? Is it possible that only a few were working and then the last 2 or so went bad, so now it won't start. BTW I did open the valve on the fuel filter and its getting plenty of fuel.

Yes it is. One goes, then the next goes, then the next, soon no worky at all!
If you think back on it you will notice that it probably was starting kinda tuff anyway.

Now the discussion will be..."Which GP's to use"...Big spade or little spade!!!

 

[thtrev2001]

Big spade, little spade??? How about the AC Delco 60G from cucv electric...always more questions than answers

 

[GPrez]

Big spade, little spade??? How about the AC Delco 60G from cucv electric...always more questions than answers

That would be the wire end that connects to the glowplug. The 60G uses a big spade. The military uses small spade plugs. If your connectors are still original on the truck you will need to put the wider spade connectors on to use the 60G plugs. Not a big deal to do.

 

[1stSarge]

Super easy to do, we sell the correct size brass connectors with housings with the AC60 plugs if you need them. The Bosch plugs with terminals will be on the site in the next couple of days.

Glow Plug System Products - CUCV Electric

 

[Warthog]

Before attemping to replace your glowplugs, PLEASE follow the glowplugs system troubleshooting section of the TM.

No need to burnup a new set of plugs if there is something else wrong with your system.

 

[Matt65]

For reference, this is what my plugs looked like before the resistor bypass. Like stated above correct any system problems before replacing them.

 

[mudman]

I used the wellman GP's. they have the 1/8' spades (military), and the Civi's have the 1/4' spade. **** Matt 65 those are wasted GP's.. I bet it starts alot better now!!!

 

[thtrev2001]

Warthog, are you talking about checking the GP module and the resistor? If so, I will get that done this weekend before I order the new GP's. I'm not that familiar with vehicle electrical systems, so if anyone has any tips, please let me know. I was actually quite proud that I was able to check the relay and GP's, if that tells you anything. Thanks for all the advice so far.

 

[ranchhopper]

Did you check the GP solenoid on the firewall if its bad no power to the GPs anyways and would make them all not work.

 

[thtrev2001]

Ranch hopper, if your talking about the Relay on the firewall, yes, I tested it, if not, I'm not sure what the solenoid is.

 

[ranchhopper]

Solenoid is the round silver part on the firewall with two small wires and two large terminals that goes klunk when the GPs cycle they will either start to chatter or will still klunk even when bad they only way to know is to see if it has power coming out when the wait to start light is on.