A few questions about my diesel.

[rs74]

I will first start by stating that I am diesel dumb. My 85 is the first one I have ever been around. With that being said I have a few questions about it.

1. How hard should it be to start in the colder weather? Since it has gotten colder it is alot harder to start. When it does fire I have to basically hold the pedal half way down in order to keep it running. It revs pretty hard doing this and I am sure it is not good on the engine but this is the only way it will stay running.

2. How much should I expect this thing to smoke. When I start it in the garage I have to open all the doors and run fans due to all the smoke it puts out. It seems to get better as it warms up but it pretty bad at the start. Its not black smoke but more blue/gray smoke.

3. I need to mount a washer fluid tank under the hood and don't have room where it is supposed to go. This truck has two semi batteries in it and they overhang the battery trays by about three inches and then where the fluid tank should go is where the glow plug controller is mounted. Not sure if they just mounted it anywhere or if it is supposed to go there. At any rate there is not enough room for it to mount to the fender.

4. This truck has had alot of hands in it in the past so I am not sure what is original to the truck or not. There is alot of wiring under the hood that is not hooked up and I have no idea what they are for. Anybody have wiring schematics for it? I have another 6.2 spare engine and looking at the two they are different in their own ways. Different plugins in different places and so forth. I would like to atleast know what all the wires that are not hooked up go to. Even if they are not needed I will know what they are for. Any help would be appreciated. Here is a pic of where the glow plug controller is mounted and showing there is no room in the factory location to mount the washer fluid tank.

[rs74]

I should add that I don't have the block heater plugged in yet. Actually I need to crawl under the truck to see if there is one in the block. I know this will probably help with the first question. One thing I am wondering about is how do I tell what type of block heater it is. Some warm up in an hour and some are more long term heaters from what I understand. If it happened to be a one hour heater then would it hurt it if I just left it plugged in all the time. I don't drive the truck full time yet but when I do need it I will want it to be ready to go. I don't want to have to worry about going out earlier and plugging it in. I would rather just leave it plugged in regardless of how long it sets in between me driving it. Will that cause any issues other than my electric bill going up?

[Idaho64GMC]

A block heater will help, mine usually need at least 1 1/2 hours do really make a difference. These are supposed to have a fast idle, push the throttle peddle down until it goes stiff to set it and then when the engine gets running and warmed up to about 120 it kicks the idle speed down. Where yours has been tinkered with by so many before you the fast idle may be messed up. Judging by your description of how hard it starts I think you have some dead glow plugs, a block heater will help if you don't want to tackle replacing those for right now. As for the smoke it again leads me to think you have a bad glow plug or two or three, white smoke is unburnt fuel so if you have a cylinder that's not firing you'll get that white smoke. All of these do that to some extent it's just the nature of them, but an engine that starts on all cylinders won't be as bad. Once it's warmed up they hardly smoke at all unless you really get on it or the pump has been turned up. Hopefully that helps you a little bit

[old Rusty C10]

a block heater is a must when its cold out like in Canada and the northern part of the US... both of my diesels (CUCV) are major pains when they are cold starting, and they smoke a decent amount . Any diesel ive driven that has been kept indoors ( im talking large trucks here) had hoses that would go over the exhaust pipes to funnel the smoke outside. There would be more than enough smoke to be annoying in the garage if they weren't used.
MY CUCV has the dual batteries too I enclosed a pic of the washer tank on the left ( drivers side fender) Im sure it could be done to either side if necessary hopefully this helps
as to the wiring you can check to see if its the old CUCV wiring harness but like im told a lot on here get a wiring tester and start checking the wires,, or find someone who can
Block heaters are cheap I get them at tractor supply for like $10-20 I did find the one that magnetic mounts to the oil pan is a little much for the trucks I own the coolant one is a lot better

[GM72K10]

Advise for good cold starting besides the block heater, good charged batteries, reclean all battery connections every year, good glowplugs. Here's what the stock washer fluid and overflow look like in my stock 86 K30 diesel dump. If you need the stock wiring schematic for your truck its on line somewhere and I have a copy of it somewhere I could dig out for you later.

[rs74]

Thanks guys!. I forgot that it also had about a half tank of old diesel that it has been running on. It sat a year before I bought it. Figured that might be an issue with the smoking so much but wasn't sure.

Where is the factory location for the glow plug controller that I posted a pic above. Evidently it's not in the right location from a few of the photos I have seen. If it were put elsewhere then I could mount the washer fluid tank there.

[83GMCK2500]

I can't remember if you have tried this yet, but forum member "hatzie" has links to wiring diagrams in his signature.

My 6.2 experience is with a '92 or '93 truck, one of the last years it was available. The coldest I've had to start it is just below freezing and after cylcing the glow plugs twice it would light up and hit on most cylinders then all 8 within seconds. Smoke? Yeah, a bit, not bad, but it was a pretty tight motor. It had massive oil leaks everywhere so I pulled it and replaced every seal/gasket I could get to without pulling the heads. Last I heard it wasn't dripping yet, been over a year.

GLOW PLUG Solenoid: It also looks like you have too large of a battery in that tray and it is interfering with where the washer fluid bottle would go. Looking at your picture, do you see all of those dimples in the fender as you move closer to the hinge? I would find a pair of them (low as to avoid hinge when hood is closed) that have the same spacing as the solenoid and mount it there. If GM72K10 can take another pic of his including the solenoid location, that would be ideal.

Beyond running and behavior related aspects I would not look too hard at the CUCVs, they are a bit of a different animal. I've been around a couple but not enough to help with anything under the hood. Voodoo 24V start/charge w/isolater block to get 12V for the truck...

[Idaho64GMC]

fuel will burn no matter what generally speaking, it's not like gas where it goes bad, that has nothing to do with the problem.

[old Rusty C10]

that relay should be on the firewall iirc old diesel will burn no matter what but I found when you put the diesel stuff in there it will burn better and clean out the fuel system its helped a lot in my CUCVs

[rs74]

Originally Posted by old Rusty C10

that relay should be on the firewall iirc old diesel will burn no matter what but I found when you put the diesel stuff in there it will burn better and clean out the fuel system its helped a lot in my CUCVs

Sorry for all the questions here but figured it would be better to throw them all in one thread verse having ten different ones. Which brings up another question I had. Someone had said to put transmission fluid in the fuel so it will lube the injection pump. Is that correct or is there something different I should be putting in there.

[rs74]

Originally Posted by 83GMCK2500

GLOW PLUG Solenoid: It also looks like you have too large of a battery in that tray and it is interfering with where the washer fluid bottle would go. Looking at your picture, do you see all of those dimples in the fender as you move closer to the hinge? I would find a pair of them (low as to avoid hinge when hood is closed) that have the same spacing as the solenoid and mount it there. If GM72K10 can take another pic of his including the solenoid location, that would be ideal.

Yeah, the battery hangs over the tray about three inches. Someone put semi style batteries in it at some point. If the solenoid/controller which ever it is was in a different location I could mount the tank there. I will have to find a tank that doesn't have a pump since I think this truck takes the pump that is on the wiper motor. The only tanks I have has the pump in the tank itself.

[mrolds88]

Several things I would check/replace on your 6.2. This comes from experience with my 6.5. Starter. I had a starter go bad on my 93. It sounded good but it wouldn't crank quite fast enough for it to light off. Last time I got it started with that one was with 2 900 amp batteries and a 800 jumping them. Had to crank to the very last possible second of battery juice. Fired and took it straight home. New starter fired it up like right now!. Glow plugs They are cheap enough. Swap them out. Just remember that sometimes the end of them swells and you wind up having to do more work. I would also just wire in a relay and a momentary push button on the dash for control of the glow plugs

[Idaho64GMC]

I use power service every other tank for lubrication, some people use transmission fluid but I don't like to do that. There are several additives lucas makes a pretty good one but I've always used power service.

[old Rusty C10]

I don't know about trans fluid in the gas I buy some stuff called Diesel Kleen or something like that at the auto parts store... it supposedly boosts cetane and has stuff to clean the system and lube the injection pump

[rs74]

I will have to check to see what the stores here have to offer. Thanks for the input so far everyone.

[83GMCK2500]

Mine has an on-tank pump and still routes it through the wiper motor as well. Your's should too.

[nekkidhillbilly]

even my 04 dmax with the better glow plugs has issues in cold it will start but barley and it smokes like crazy till warm.

[crashz]

The 6.2 is notorious for hard starting in the cold. On every one I've owned, if it does not fire on the first try, you better break out the battery charger.

That said, I think the big Group 31 batteries you have are a good thing. Keep them, re-rout the washer bottle, clean the end terminals, plug in your block heater and you should be good to go. Note how clean GM72K10's battery connnections and cables are. Clean, tight connections are key, as there is a lot of juice demand during start-up. I'm going to pull my cables and have new 0/2 gauge cables made up to handle the starting.

Typically a block heater should be used on these trucks at or around the freezing point, but in any cold weather it will help.

As stated above, the starters have a finite life. Spinning a 22.5:1 compression engine is not easy, even for those monster starters. A quality re-man (electric shop) or GM starter is expensive bt worth it. Don't forget to make sure the little bracket at the fron is re-installed. Later models have a gear reduction starter that some people like. Others like the monster direct drive. I've had both fail, but my next will be Powermaster's gear reduction starter.

The glow plug controller on 85+ is on the driver side head, towards the firewall. Its easiest to reach by taking the air cleaner off first. Yours does look like the older style (someone had trouble with it?) with the fender mounted solenoid.

The stock plugs burn out and can mushroom the tips. Don't try and force them out as they will break. What nobody talks about is that they will be dificult to remove even if they don't mushroom. besides corrosion, the carbon builds up around them and you'll need a little WD40 or something to help pull them out. I was nervouse about breaking a tip off, but very gentle pressure and twisting pulled them slowly. The stock AC9's burn out, the AC6's will work fine, but don't get quite as hot. Kenndey diesel sells a good plug at reasonable prices.

I haven't tried a 0w-40 oil yet, but that might help a little too.

[83GMCK2500]

I know they're from overseas but the aftermarket gear reduction starters are friggen awesome. They spin hard with a pair of 1000CA Group 78s behind them.

[old Rusty C10]

If youre going to use new glow plugs get the delco 60G they are the best for these motors

[rs74]

I do need to test the glow plugs to see if they are all working. I also crawled under the truck yesterday and saw that there is no block heater installed in the drivers side freeze plug location. I will probably have to break down and try to get the freeze plug out. Something I have never had to do was knock out a good sealed freeze plug. Makes me feel like I am doing something that I shouldn't be.

I was told they just had the starter rebuilt and from looking at it I would say it is. Looks brand new. Thinking maybe the engine is a reman from the way it looks underneath. All nice and shiny freeze plugs and the paint on the engine is clean and just reminds me of a reman.

Not sure if anyone ever had issues with the controller/solenoid but it came with two spares just like the one pictured. I also have what look to be a couple of oil cooler lines that would have went to the oil filter area (?) I will have to look a little closer to see where they are supposed to go but they are not hooked up to the engine.

Thanks for all your thought guys. Glad there are some guys who know something about these diesels here. Much appreciated.

[old Rusty C10]

I would get the heater that goes in the coolant hose instead.. those freeze out ones always create problems leaking

[Idaho64GMC]

You're extremely lucky if it's just been rebuily and is all clean underneath, I worked on mine yesterday and came out black from one end to the other lol, and that was AFTER steam pressure washing it for an hour.

[crashz]

Yeah these motors do not remain clean for long. But they help keep the rust at bay!

To test the glow plugs, the best way is to pull each one, ground the body, and apply 12V to the spade connection. If it glows red hot (be carefull!), its good. If not glowing red, its done. Personally, if you are going to pull them to test, I'd just replace them.

I second Rusty's advice. It might be tough to re-seal the block heater in the truck.

There are oil cooler hoses on the driver's side that connect from the oil fitler block to aluminum lines that cross the radiator in front of the fan and into the radiator cooler. The hoses are notorious for leaks and blowing out at the crimp ends. If the PO had a line blow, he may have had to replace the engine, and I'm sure he would be soured on reconnecting the cooler. I'm not sure if you said that the lines were removed or if you simply have spares. These motors generate a lot of heat and really need the oil cooler.

[D13]

1. Modern ATF is not diesel fuel. Don't waste your time or money. Some Diesel Clean or Diesel + wil help old fuel.
2. Diesels smoke cold. Should be greyish with pehap[s a little blue tinge, should go away in a minute or so.
3. Replace the glows with 60G's and use a (GASP!) F*rd starter relay with an override to give them an extra 10 seconds. MIne is in parallel, if it's warm the stock relay works, if the motor's cold I override it to get he 60G's going. They heat slower but don't develop the swollen tips.
4. Block heater below freezing is good. Saves wear and tear on everything else.
5. Never use glows and ether. Ether will pop off too early. 6.2's that are gloed and ethered bend rods.
6. On the bottles, I can't help you, the big batterires are nice but definitely why your stuff is mispositioned.
7. Clean all cables and connections. Critical that the starter see full power.