1986 doesnt start without starting fluid then runs perfect

[6-2DIESEL]

hey everyone! i was wondering if you guys could help me out here as this thing is leaving me kind of stumped.

i bought this truck from a friend of mine and he also kind of gave up on it. any way the truck will not start with out starting fluid no matter what the temperature is, but once its started it runs perfect! and your able to restart it with out any problems until the motor cools down. its a 1986 k5 military blazer and the only thing that has been done to it was new glow plugs and a manual glow plug switch but it hasnt solved the problem.

i know the injection pumps go bad on these but once its running theres no hesitation or anything like that so im not sure. i dont know much about these motors so if you guys could point me in the right direction id appreciate it! hope you all had a good Christmas and have a happy new year

[D.Camilleri]

to the diesel place. Please fill out your signature so we can help you easier.

Now, you say you have replaced the glow plugs and installed a manual switch, do you know that they are working? What type of glow plugs did you install? Is your blazer still 24 volts?

[6-2DIESEL]

Originally Posted by D.Camilleri

to the diesel place. Please fill out your signature so we can help you easier.

Now, you say you have replaced the glow plugs and installed a manual switch, do you know that they are working? What type of glow plugs did you install? Is your blazer still 24 volts?

thank you!

and yes the previous owner replaced them with autozone glow plugs im not sure what the actual brand is. it is still in a 24 volt system, i had the plugs on an ohm meter yesterday and they tested right at 24 volts so there all working too

[D.Camilleri]

Let me clarify testing the glow plugs:
1) When the manual button is pushed, test the voltage at each wire with the wire unhooked from the glow plug.

2) With the glow plug wires disconnected from the glow plugs, take the ohlm meter and test for continuity from the center electrode of each glow plug to ground or the easy way to test them is with a test light.

3) I am not sure if the military rigs use 24 volts to the glow plugs or 12 volts, the original civilian 6.2's used 6 volt glow plugs and powered them with 12 volts, the problem was if the controller stayed on for two seconds too long it would burn them all out. Those were the old 9G glow plugs. If you bought your glows at auto zone, they probably sold you 60G's or equivilent that are 12 volt glows, but I don't know if they would last very long with 24 volts powering them. My guess is that your glow plugs are all burned out. If this is the case, I would wire your glow plugs to be only 12 volts, easy to do by only wiring from one battery.

[6-2DIESEL]

Originally Posted by D.Camilleri

Let me clarify testing the glow plugs:
1) When the manual button is pushed, test the voltage at each wire with the wire unhooked from the glow plug.

2) With the glow plug wires disconnected from the glow plugs, take the ohlm meter and test for continuity from the center electrode of each glow plug to ground or the easy way to test them is with a test light.

3) I am not sure if the military rigs use 24 volts to the glow plugs or 12 volts, the original civilian 6.2's used 6 volt glow plugs and powered them with 12 volts, the problem was if the controller stayed on for two seconds too long it would burn them all out. Those were the old 9G glow plugs. If you bought your glows at auto zone, they probably sold you 60G's or equivilent that are 12 volt glows, but I don't know if they would last very long with 24 volts powering them. My guess is that your glow plugs are all burned out. If this is the case, I would wire your glow plugs to be only 12 volts, easy to do by only wiring from one battery.

So to test them for step number 2 i need to take each one out again correct?

like i said im n sure which ones he bought. im going to try and get a hold of him tomorrow and see if he knows. i would assume he got 12v because he didnt mention anything about having to order 24v ones.

if i was to buy 12v glows again, how do i properly wire them directly from the batter to 12v again so i know im safe and that its correct?

thank you for the help so far, i really hope its my glows and not my injection pump

[turbonator]

welcome to DP... now, since our esteemed moderator has not said it, i will.... DO NOT USE ETHER!!!!!! if you use ether you will have bigger problems than just changing the injection pump...( think of one of the heads blowing off and landing in your lap behind the steering wheel bad)....use wd-40 instead, and just a tiny bit.... if you go and look at the glow-plugs, 24volt have round connector, and 12 volt have flat ones ( bullet versus spade style)..... these IDI engines can bend the rods with continual ether use, and become "addicted" to it, and not start any other way, we hope this is not the case with yours... how many times do you estimate in the last 2 months has it been started with ether/starting fluid? go here to see what happens......http://www.dieselplace.com/forum/ann....php?f=20&a=86

[6-2DIESEL]

Originally Posted by turbonator

welcome to DP... now, since our esteemed moderator has not said it, i will.... DO NOT USE ETHER!!!!!! if you use ether you will have bigger problems than just changing the injection pump...( think of one of the heads blowing off and landing in your lap behind the steering wheel bad)....use wd-40 instead, and just a tiny bit.... if you go and look at the glow-plugs, 24volt have round connector, and 12 volt have flat ones ( bullet versus spade style)..... these IDI engines can bend the rods with continual ether use, and become "addicted" to it, and not start any other way, we hope this is not the case with yours... how many times do you estimate in the last 2 months has it been started with ether/starting fluid? go here to see what happens......http://www.dieselplace.com/forum/ann....php?f=20&a=86

Thank you!

I know a few things about diesel and I know I'm not supposed to be using starting fluid, but this thing will not start with out using it. I have tried WD-40 and I get nothing from it thats why ive been using it I know I'm wrong for using starting fluid but on the bring side the truck is not driven daily by me yet, I only start it to move it or to bring it somewhere warm to work on it haha

I really hope this one had not become "addicted" to it...

I'm not sure how often he used starting fluid to start it but ive only done it about 5 or 6 times

One thing i do know is these are flat pin connectors so they must be 12v, could this be my whole problem not having the 24v glows?

I appreciate all your guys help so far! hope you gusy have a good new years!

p.s. does it matter if the starting fluid i have is safe for diesels? i believe it says gas and diesel on the can but i could be wrong..

[6-2DIESEL]

I just read the other post, i really hope thats not the case with mine..

[IamDave0887]

The military blazers ran 12 volt glow plugs.

The only things that were 24 volt was the starter, and the charging system.

There was a large inline resistor that would drop the voltage down to ~12 volts or so. The rest of the truck was powered after this resistor, so everything else remained a 12 volt setup.

If you have 24 volts at the glow plugs, and you are using 12 volt glows, they are dead. Not even worth testing them out. 12 volt glowplugs are actually rated at 10.5 volts due to the large drop that occurs when powering the glows(roughly 110 amps pulled from the batteries causes the voltage to drop down to ~10.5-11.0 volts).

Just imagine a 6 volt light bulb running on 12 volts. Imagine how long it would last before going poof. Same concept with double the voltage at the glowplugs. Regardless of the glowplug you are using, they aren't meant to take that voltage, so they will fail.

Odds are you ended up with Champion or Autolite glowplugs, which are pure garbage. Do yourself a favor and track down a set of Bosch Duraterm part # 80034 and install those. I've been running my first set of those since 2008 in my 6.5(with ~15 second glow times too) and since 2009 in my K-5(with up to 25 second glow times in the extreme cold) and all 16 are still good.

Keep away from the starting fluid. In fact take the can outside and either empty it, or throw it away and do not buy more.


I have one can of starting fluid at the house, and 3 diesels. My 6.5, my 6.2, and my fathers X595 3 cyl Yanmar diesel tractor. I always said if i found that ether can next to either of those 3 vehicles heads would roll by time i was finished.

That can sits in the cabinet with dust around it it hasn't moved in so long.

A properly running 6.5 or 6.2 will not need ether, or any starting aid to start, in any temperature. I started my 6.2 in 25*F weather, complete with wind and snow, yesterday leaving work. After the normal glow time plus ~5-7 seconds extra she fired right up with a lot of rattling and clacking, but she fired on all 8 right away and stayed running on all 8.

That's how a 6.2 or 6.5 should start in any weather.

Ether is to diesels like crack cocaine is to humans. The more you use it the more it is needed. It becomes an addiction that cannot be broken once it has begun.

If you can find a diesel compression tester(gauge has to go to at least 500 psi, mine goes to 1,000 psi) and a glowplug adapter, then un-hook the Pink wire on top of your injection pump and remove all 8 glowplugs. Thread the adapter into the glowplug hole, hook up the gauge, and crank the engine over to get ~6 "puffs" on the tester.

Check your compression numbers. 400 psi is the spec. When i bought my K-5 i had a few cylinder at 390-400 psi, and a few down to as low as 350 psi. This was after the engine sat dormant for 10+ years in the truck.

I've since put over 20,000 miles on this engine(with the last 10,000+ being turbocharged) and i'm sure the compression numbers have come up.

[smackzed]

Originally Posted by IamDave0887

The military blazers ran 12 volt glow plugs.

The only things that were 24 volt was the starter, and the charging system.

small point but isn't the inj pump 24v as well?