Are My Glow Plugs Bad???

[tyluk]

Hey everyone. So I'm wondering if I have glow plug issues. In the morning when I go to start my 83 quantum it has to crank for about 40 seconds before it actually continues to run on its own. This entire time there is blue smoke (unburned fuel?) billowing from the tailpipe. After this initial start it runs fine the rest of the day. Just began happening after a 2,000 mile journey. Just wondering if I need new glow plugs or if it is a relay or something. Thanks for the help.

[Possum79]

Smoke Defined

[Op-Ivy]

Along with your other post it really does sound like your headgasket is done. If it takes that long to crank you may have poor compression and I would do a compression test if I were you.

[tyluk]

Where is the fuse for the glow plugs. I want to check the fuse. I've seen maybe on the firewall or under the dash. I don't see anything on my firewall when following the wire. It goes behind a bunch of junk and then i'm not sure if it heads into the firewall from there or towards the front of the car. I don't see anything that stands out.

[jtanguay]

i think its a combination of valve sealing issues and bad glow plugs.  so bad compression & bad glows.  theres probably tons of life left in the motor though.. could even be rings.

whats the history on this motor? has it ever overheated when in your care?  any work done to it such as rebuild, new rings, etc??

[tyluk]

I don't know the history of the car. I bought it for $250 and drove it from NJ coast to Colorado (actually had a friend drive it). He said it never overheated for him. Once it got here started having the starting problem the next morning after arrival. Never had an issue in Jersey driving it there for a month. It basically started overnight. After the first start in the morning (40 -50 degrees) it runs and starts fine rest of the day.

[jtanguay]

I don't know the history of the car. I bought it for $250 and drove it from NJ coast to Colorado (actually had a friend drive it). He said it never overheated for him. Once it got here started having the starting problem the next morning after arrival. Never had an issue in Jersey driving it there for a month. It basically started overnight. After the first start in the morning (40 -50 degrees) it runs and starts fine rest of the day.

3 of my GP's burnt out on me at around the same time... car would not start  

[zukgod1]

Pull them out and see, it's almost easier to pull the injectors to see then I think.
It's just easier with all the pipes etc out of the way.

First things first though. stick a test light on the bus bar and see if they are getting power, if not trace backwards till you find the problem, if there is power you will need to check each one..

[tyluk]

I do want to check the bus bar but where is it? I followed the glow plug wires into a bundle. Then they go back behind the brake master cylinder and then the coolant tank. From there I don't know where it goes. I thought the bus bar was on the firewall engine side but I can't find it. Is it inside the car near the fuses? Just give me hint. Thanks.

[burn_your_money]

The bus bar is the chunk of copper that connects all the glowplugs. Check for power there.

[burnt_servo]

find a amp meter  , and put in in the circuit that powers the glow plugs .

each glow plug draws 10 amps , 4 good glow plugs = 40 amps draw .....

3 good glow plugs = 30 amps draw .... and so forth

[burn_your_money]

that only works some times. On occasion they fail closed and will give a false reading

[tyluk]

Okay I appreciate all the great information but I'm still confused. I hope I'm not just an idiot but where is this bus bar (or chunk of copper)? In what general area should I be looking for it. Like I said I followed the wire from the GPs but didn't find anything on the engine side. Please give me a little more info if you can. Thanks.

[clbanman]

The "bus bar" is the flat copper bar that runs between the 4 glow plugs.  If you connect a test light to it, you can tell if you have power to the plugs, but that won't tell you if the plugs are ok.  Like jtanguay, I had 3 of 4 plugs fail - fine one day, next morning I couldn't start the car, and it was well above freezing out.  Replaced all 4 plugs, started like new.

[tyluk]

Thank you so much for the clarification. I will try a test light on it tomorrow and let you know what I find. Like I said, working great one day and then the next won't start. Hopefully just something kinda simple.