1988 M998 Cold Start Problem

[tonydamato]

Yeah I shot him a PM the other day asking him specifics and he never got back to me, not upset, I know he has a business to run..
I just ordered a KDS box this morning, figure its worth doing as im going to replace glow plugs too.

 

[gcbennet]

The new boxes are overly fragile for their application in a purpose-built military vehicle (IMO), and some say keep using the old clunk box until it dies. Weak batteries and power surges will kill the new ones. Sometimes they just stop working properly for unknown reasons. It's solid state and fed info from multiple sources, and if it detects any anomalies the box will respond. I've been stranded in a parking lot in the winter because the plugs would not fire for whatever reason and I wore the batteries down attempting to start on cold cylinders. After I recharged and tested the batteries it turns out one of them was showing full charge but failing under load, which screwed with the box on startup. New batteries and she works fine ever since, and luckily I didn't blow the box this time. To help lessen the load I installed a block heater in mine which really helps for the cold nights, and she fires right up in the morning on only a couple of rotations, not to mention heats up way quicker. On just the plugs she fires up on 4-6 rotations and chugs for several seconds with twice as much smoke before she finds her mojo.

 

[NormB]

Had a second today after doing coolant flush, replacing all hoses, thermostat & installing block heater.
Tested glow plug lead (only 1) and found that it's getting 24v when key is in the on position constantly, regardless if coolant is cold or hot and stays 24v after the light goes out. The wait light acts like it should, only glowing for 9 seconds during a cold start and not when engine is warm. The power goes off to the plugs after the engine starts.

Have to test the plugs, but more then likely the new plugs in there will be fried, hence the cold start issue.
So, I'm assuming I have a box issue, although the wait light is working properly. If I need to replace the box, do I get a new Nartron Electrical Start System & SSI?
I currently have a Nartron Yellow Label.
Additionally, does anybody find this system to be a little silly & overly complicated? Hard to keep track of all the parts in the system. Is there anything simpler out there to replace it? Manually operated glow plug switch set up perhaps?

S3 unit's the way to go, Box AND TSU - and get MILSPEC glow plugs, about $70 a set. Yeah, they're mfd by Welman (aka "swellman") but they can all swell. Less so with the newer PCB/S3 system as they turn off the plugs sooner.

If you CAN, find someone you can borrow a plug puller from - they range from $30-$90 and if you NEED one, you'll appreciate having it. If you don't it'll be different. Much.

 

[ikoinu]

Tony, ponied up on the big box huh? How much?

Tried the block heater with the plugs not working last night, fired up not too bad. Going to get a timer and run it 3 hours ahead for early wake up tomorrow an see how she does. Will report back.

As far as boxes go, I think I will just opt out. Ordering another military glow plug harness, as I don't want to cut into my factory. Going to unplug the factory, plug in a secondary with new plugs, attach a high amperage 24v relay, momentary push button switch, wire it all up and bob's your uncle.
When I finish, I'll test it out, take some pictures and get some part numbers to make it easy on anybody else who doesn't want to do the box grind anymore.

Norm, plug puller's a good call, ordered one. Going with the factory Swellmans, as they won't burn out if I'm not relying on a box to make decisions for me.

Wish me luck!

 

[tonydamato]

That sounds like an interesting idea....

I bought the KDS box and sensor through Hummerpartsguy for $475 I think, id have to look at the invoice for sure, bought bunch of stuff.

 

[ikoinu]

Yeah, I remember seeing it on Ebay for like $600.
Everybody says it's the best. It's the KDS S3 right? So many parts and names for the same thing, difficult to keep track.

 

[Action]

Without rereading the entire thread, did you try the cold advance switch?

 

[ikoinu]

I had replaced the temp switch. The main problem I was having is 24v going to plugs full time (when engine is not running). Bad box.

Reporting back, the block heater works great! Keep in mind it was 50 degrees this morning so not cold. Had the heater on 2 hours in advance with a timer, 1000w so it does the job. Going down to 1 hour tomorrow. Didn't start yesterday with no heater, fired up on first crank today. Good working fix until I set up the manual glow plugs.

 

[tonydamato]

Yeah the 1000w block heater from Zerostart makes a world of difference. Regardless of climate, no diesel should ever be sold without a block heater. For what it costs I don't understand why they don't all have them, its dumbfounding to me.

 

[NormB]

I had replaced the temp switch. The main problem I was having is 24v going to plugs full time (when engine is not running). Bad box.

Reporting back, the block heater works great! Keep in mind it was 50 degrees this morning so not cold. Had the heater on 2 hours in advance with a timer, 1000w so it does the job. Going down to 1 hour tomorrow. Didn't start yesterday with no heater, fired up on first crank today. Good working fix until I set up the manual glow plugs.

Which zerostart model did you wind up buying?

I‘ve been all over the usual online auto parts places, the phillips and temro site and 20 minutes later am no closer to figuring out which plug DOES fit vs. which one MAY fit.

Thanks.

edit:

Nope, nope, I got it.

Did a websearch for “zerostart AND GM AND 6.2L” and found this:

http://thedieselstore.com/zerostart-engine-heater-for-1981-2002-6-2l-6-5l-gm-diesel-engines.html

Model #3100059.

That the one you used?

PS: if your electric bill is already “skyrocketing” as former white house resident Obeyme warned his method of cap and trade would guarantee, you might consider one of these:

https://smile.amazon.com/Farm-Innov...atcorr&keywords=engine+heater+receptacle&th=1

The trucks are supposed to start quickly at/over 35 something degrees, or there’s something else wrong with the electrics or IP, or starter, or...