6.2L diesel question

[K5dreamer]

ok the truck is a 1986 M1009 diesel, and ive noticed that starting in cold weather is a bear. it cranks and cranks and i have to press the gas pedal down to get it to fire.

heres the thing, i always turn the key to "on" and wait a good 10-20 seconds before cranking the engine, but i never see the "wait" light.

then today, i go to start the truck, see the wait light and wait for it to turn off. crank the engine and it fires right up.

so i guess im wondering if this could be a glow plug relay problem. like an intermittant electrical problem. i thought it just had the original glow plugs and they werent doing the job anymore, but after today with the wait light working and then the truck firing up after two, maybe three cranks, im thinking the problem is something else.

any ideas?

 

[u2slow]

I wonder if your relay is making contact all the time. In my case, if the light didn't come on, it meant the GPs weren't getting lit - even though I heard the relay. The relay was cycling, but not reliably making contact.

Your visor instructions should say to use 1/4 or 1/2 throttle for starting depending on the outside temperature.

 

[85-m1028]

Pull the controler card and clean the contacts a bit. Check all the connectons and power leads. To test the glow plugs use an ohm meter, resistance should read about 1.5ohms.

 

[Smitty]

Sounds like your controller. I'd recommend going to a site like www.steelsoldiers.com and downloading the technical manual for your m1009. The manual has a great troubleshooting guide for the glow plug system.

My 86 m1031 had a problem with starting when I got it. My "Wait" light would come on and cycle, but the vehicle would not start. Turned out that the relay would actually cycle, but it wasn't allowing electricity through the main contacts.

 

[dremu]

Sounds like your controller. I'd recommend going to a site like www.steelsoldiers.com and downloading the technical manual for your m1009. The manual has a great troubleshooting guide for the glow plug system.

My 86 m1031 had a problem with starting when I got it. My "Wait" light would come on and cycle, but the vehicle would not start. Turned out that the relay would actually cycle, but it wasn't allowing electricity through the main contacts.

Brief shameless self-plug ... I have all the TM's for the CUCV's on

http://brochures.slosh.com

as well.

IIRC, the CUCV's have a different glow plug setup than the civvies ... haven't had to tear into mine yet, but something to watch for. At the very least there's the whole 24V mess, grrr.

-- A

 

[Smitty]

Brief shameless self-plug ... I have all the TM's for the CUCV's on

http://brochures.slosh.com

as well.

IIRC, the CUCV's have a different glow plug setup than the civvies ... haven't had to tear into mine yet, but something to watch for. At the very least there's the whole 24V mess, grrr.

-- A

Do you have the following for the M1031?

TM 9-4940-562-23P
TM 9-4940-562-13

 

[K5dreamer]

thanks for the replys everyone,

i can go check the resistance on the glowplugs pretty easy, its still light outside.

as for cleaning the relay contacts and pulling the control board contacts, imma have to claim ignorance on where those are right now. can anyone point me in the right direction.

dremu, thanks so much for the site, i saved a copy of everything pertaining to my truck and will probly be spending the evenings for the next week going through all that information. one question though, i couldnt find any information on the wiring harness for the 1986 6.2L diesel, is it the same as the 1982 6.2 harness you have listed? it does have the old V belt system, so its not the newer serpentine belt engine. and to my knowledge there were only the two models of that particular engine.

 

[dremu]

thanks for the replys everyone,

i can go check the resistance on the glowplugs pretty easy, its still light outside.

as for cleaning the relay contacts and pulling the control board contacts, imma have to claim ignorance on where those are right now. can anyone point me in the right direction.

dremu, thanks so much for the site, i saved a copy of everything pertaining to my truck and will probly be spending the evenings for the next week going through all that information. one question though, i couldnt find any information on the wiring harness for the 1986 6.2L diesel, is it the same as the 1982 6.2 harness you have listed? it does have the old V belt system, so its not the newer serpentine belt engine. and to my knowledge there were only the two models of that particular engine.

Eh. The CUCV's are an odd lot with the 12/24V thing, so you're prolly better off using the military manuals than the wiring diagrams I have there

-- A

 

[dremu]

Do you have the following for the M1031?

TM 9-4940-562-23P
TM 9-4940-562-13

Dangit. Don't seem to. Can you get them from LOGSA?

-- A

 

[85-m1028]

The controler card is under the dash by the steering coumn. One thing I will point out is that the connectors that go to the glow plugs are a funky 3/16". I's best to just cut those off and find some insulated 1/4" female tang connectors and crimp those in place.

recomend using AC Delco 60G's

 

[K5dreamer]

ok everyone, i tested the glowplugs as follows....

pulled the connector, put the positive probe on the metal tab, and the negative probe on the (guessing) 3/8in hex head for installing and removing them.

Cylender 1 - 157 ohms
Cylender 2 - 1.9 ohms
3 - open
4 - open
5 - open
6 - open
7 - 2.0 ohms
8 - open

and now the truck wont start at all. just blows puffs of white smoke. so ive got cranking (both batteries are close to 13 volts) and obviousy fuel. the glowplugs are the only thing i messed with. and the pink wire to the fuel pump which is back in place. and still no wait light comes on.

im not 100% sure of those readings on the glow plugs, theres alot of mud and corrosion under there, but i did dig the probe tip in pretty hard. which should have got through all that stuff.

but with my luck those are the original glow plugs for the truck, so they might be 20 odd years old and just need to be replaced. so i have three questions.

1. how much do glowplugs cost?

2. ive heard horror stories about trying to get those things out and having them strip, or break. is replacing those things something i can do pretty easy or should i pay a shop to do it and let them handle the **** that goes wrong?

3. are these glowplugs something i have to get from the dealer, or are they carried by napa or something else. I normally use all AC-delco for my cars, but if there is a reasonably priced, reliable alternative id be interested.

 

[tRustyK5]

It only takes two or three bad glow plugs to create a 'no-start' situation for a 6.2. The fact the glow light isn't coming on could point to a bad controller or relay too.

Glow plugs are available everywhere. Average cost I've seen is about $10 each. Do not get the old 9G or 11G glow plugs. They swell the tips up when they glow too long.

If you're keeping the stock glow plug control I'd recomend some "Quick heat" glow plugs from Kennedy diesel. They hit full glow in less than 5 seconds. An alternative is the AC 60G which is also a constant duty glow plug, but they can take 12-15 seconds to hit full glow...so they don't work well with the stock glow controller. The conversion to manual control glow plugs is very easy though.

Anyways, the "Quick heats" are great if you can wait for them to show up.

www.kennedydiesel.com

Autolite also makes the constant duty glow plugs, they're the 1110's. They'll also work fine. I have three of those and five AC 60G's right now.

Hopefully you'll be able to spin out the old GP's. They can be a real bear if the tips are swollen...

It isn't a hard job really, I'd try it yourself first. If you find any with swollen tips do not get impatient and try and force the issue. Keep trying to spin it out and usually the tip will unthread through the hole. If they're not swollen it's about a 40 minute job tops.

Rene

 

[85-m1028]

ok everyone, i tested the glowplugs as follows....

pulled the connector, put the positive probe on the metal tab, and the negative probe on the (guessing) 3/8in hex head for installing and removing them.

Cylender 1 - 157 ohms
Cylender 2 - 1.9 ohms
3 - open
4 - open
5 - open
6 - open
7 - 2.0 ohms
8 - open

and now the truck wont start at all. just blows puffs of white smoke. so ive got cranking (both batteries are close to 13 volts) and obviousy fuel. the glowplugs are the only thing i messed with. and the pink wire to the fuel pump which is back in place. and still no wait light comes on.

im not 100% sure of those readings on the glow plugs, theres alot of mud and corrosion under there, but i did dig the probe tip in pretty hard. which should have got through all that stuff.

but with my luck those are the original glow plugs for the truck, so they might be 20 odd years old and just need to be replaced. so i have three questions.

1. how much do glowplugs cost?

2. ive heard horror stories about trying to get those things out and having them strip, or break. is replacing those things something i can do pretty easy or should i pay a shop to do it and let them handle the **** that goes wrong?

3. are these glowplugs something i have to get from the dealer, or are they carried by napa or something else. I normally use all AC-delco for my cars, but if there is a reasonably priced, reliable alternative id be interested.

I use the autolite 1110 myself " I didn't know that they are a constant duty plug" that's why I always recomend the delco 60G's

The constant duty cycle plugs work better bacause they last longer with the 24v stepdown to 14v system used in the cucv. The resistor "mounted on the center of the firewall" doesn't drop the voltage right away.

Again, while your at the parts store pick up a pack of insulated 1/4" female tang connectors and change them out. The stock ones won't fit the larger tang.

Trust me when I say that getting a new set of the mil spec AC Delco 13G or wellman glow plugs, will leave in you same predicament your in within a week or two I'd put money on that!!

If any of the old plugs are swollen I just clamp some visegrips on the em and pull staight back and rotate back, forth.... should come out with some patience, persistance, and muscle. just dont bend em!!!!

 

[85-m1028]

It only takes two or three bad glow plugs to create a 'no-start' situation for a 6.2. The fact the glow light isn't coming on could point to a bad controller or relay too.

When you get down to just a couple of plugs the light will generaly only come on for a second if at all...

 

[K5dreamer]

thanks again everyone for all the help, i happen to be sick right now, so i guess ill take a sick day tomorrow, get the plugs and get to work. ive also got some parts for the rear brakes and parking brake. so i guess it will be a busy day.

ill repost when all is said and done and let yall know if the glowplugs fixed the problem.