Glow Plug Check

The place to discuss problems and routine maintenance questions and tips. This is for topics that are specifically diesel-related.
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I'm luving it
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Glow Plug Check

Postby I'm luving it » Sat Oct 05, 2019 1:00 pm

Just a reminder....if your glow plug system starts acting up check the glow plugs as soon as you can. I think a lot of people scrap the glow plug system without fully understanding it or trouble shooting it. Trouble shooting the issue will keep a good system working properly. In the last five years my problems have been confined to bad plugs and one bad relay. When working properly my truck takes 5 seconds to start from temps down to -40 (yes -40).

My glow plugs system started acting up. Hard starting when cold and lots of smoke. I kept putting off checking them since I thought it was other issues (Air, wiring, fuel drain back, etc). After several months I decided to check plugs with a meter. It super easy to check them with a meter while still in the motor. I found that glow plug one was bad. I pulled the plug and found the tip missing. I have no idea when it happened. The glow plug is a stock Isuzu glow plug. Maybe if I would have checked it sooner I could have avoided this. I installed 4 fresh NGK plugs. I will watch that cylinder and see if the plug goes bad again. Maybe it’s a injector issue. Hope no harm was done to cylinder.
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-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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Halden
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Isuzu vehicle(s): 1983 Diesel LS Long Bed 4x4

Re: Glow Plug Check

Postby Halden » Sat Oct 05, 2019 8:53 pm

No damage to the cylinder will have been done. Once it works it's way out of the precup the piston will have just smashed it to dust and out the exhaust valve
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Bed Diesel 4x4
82 LUV Short Bed Diesel 5 Speed 2wd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

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JoeIsuzu
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Location: Germantown (next to Elvistown), TN
Isuzu vehicle(s): Original owner, '83 LS Diesel, 5-spd, 2wd, Long Bed, restoration in progress!

Re: Glow Plug Check

Postby JoeIsuzu » Sat Oct 05, 2019 9:20 pm

Halden wrote:No damage to the cylinder will have been done. Once it works it's way out of the precup the piston will have just smashed it to dust and out the exhaust valve

Remember the hole in my piston? The cylinder with a broken glow plug tip.

Jack

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I'm luving it
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Re: Glow Plug Check

Postby I'm luving it » Sun Oct 06, 2019 3:12 pm

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Hundred miles later....Looks like it’s time for injectors to be rebuilt. I would guess a bad spray pattern. Same cylinder and the glow plug tip is missing. Grrrrrrrrrrr. I have a spare set of turbo injectors that I will drop off to have them set up to NA pop off pressure. They do have different part numbers than NA injectors so I’ll have to research to see if they will work.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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I'm luving it
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Re: Glow Plug Check

Postby I'm luving it » Sun Oct 06, 2019 3:18 pm

Hope it didn’t cause any other damage. I will test compression eventually. I know what compression was before this issue.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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Halden
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Isuzu vehicle(s): 1983 Diesel LS Long Bed 4x4

Re: Glow Plug Check

Postby Halden » Sun Oct 06, 2019 8:19 pm

JoeIsuzu wrote:
Halden wrote:No damage to the cylinder will have been done. Once it works it's way out of the precup the piston will have just smashed it to dust and out the exhaust valve

Remember the hole in my piston? The cylinder with a broken glow plug tip.

Jack


I suppose that could have caused the hole in your piston. I don't know that I've ever seen, besides yours, a bad plug putting a hole in a piston. I would have figured a bad casting, or bad fuel.
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Bed Diesel 4x4
82 LUV Short Bed Diesel 5 Speed 2wd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

Eric Q.
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Location: Auburn, WA

Re: Glow Plug Check

Postby Eric Q. » Mon Oct 07, 2019 9:41 am

Hey Luvin'

Setting the pop-off pressure isn't too hard to do. Jasonw86 & I did this a while back and I think he still has the gauge & hydraulic ram we used. Heck, he might even have a spare set of NA injectors.

Best of luck,
Eric Q.
'75 body with '81 diesel running gear

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I'm luving it
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Re: Glow Plug Check

Postby I'm luving it » Tue Oct 08, 2019 8:52 pm

Are the injectors the same just different pop off pressure between turbo and non turbo? I want to take a set of turbo injectors and have them set to Non-turbo pressure. The part numbers are different on the two injectors.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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Paul
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Re: Glow Plug Check

Postby Paul » Wed Oct 09, 2019 12:39 am

Best I can tell the injectors are the same, just different pop off pressures. Probably why they have a different p/n. You should be able to reset the pop off OK. Might want to watch for the quality of the fuel spray while you're at it.

Be careful to stay away from the spray with your body.

Paul
'84 P'UP 2 wd diesel, 5 spd with 0.78 fifth gear and differential back to 3.73.

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I'm luving it
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Re: Glow Plug Check

Postby I'm luving it » Wed Oct 09, 2019 12:56 am

Thank you Paul! I called your shop today pricing a Turbo pump rebuild. The guy that answered the phone spoke highly of you and your skill.
I decided to keep my NA pump since is working fine and just set the injectors to the NA pop off pressure. I am having a local injector shop rebuild the injectors tomorrow. If my NA pump goes bad I’ll have the turbo pump rebuilt and install it.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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Halden
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Isuzu vehicle(s): 1983 Diesel LS Long Bed 4x4

Re: Glow Plug Check

Postby Halden » Wed Oct 09, 2019 8:57 am

I'm luving it wrote:Thank you Paul! I called your shop today pricing a Turbo pump rebuild. The guy that answered the phone spoke highly of you and your skill.
I decided to keep my NA pump since is working fine and just set the injectors to the NA pop off pressure. I am having a local injector shop rebuild the injectors tomorrow. If my NA pump goes bad I’ll have the turbo pump rebuilt and install it.


If that pump fails, I'd like to take/buy it from you. Though I can't imagine that it would.
It's not pronounced "Ih-soo-zoo", it's pronounced "It-screws-you"
83 LS Long Bed Diesel 4x4
82 LUV Short Bed Diesel 5 Speed 2wd
64 Chevy C20 w/ 283 & 4 speed.
05 Sonata with a standard

User avatar
I'm luving it
Regular Member
Posts: 254
Joined: Mon Apr 08, 2013 11:36 am
Location: Seattle, WA

Re: Glow Plug Check

Postby I'm luving it » Wed Oct 09, 2019 4:12 pm

I received this from Jerry Lemond:

THEY ARE THE SAME INJ, THE NON TURBOS ARE SET AT 1500 PSI AND THE TURBO ARE SET AT 1900 THE ENTIRE BODY AND NOZZELLS ARE THE SAME A COMPLETE NEW IZIZU INJ ASSY WOULD HAVE A DIFF PT NO BECAUSE THEY WOULD COME PRE SET..

I dropped the injectors off at Seattle Injectors this morning. The guys there were really knowledgeable and help. I told them 1500 pop off and they recommend going 200 over stock to “help with smoke”. I told them ok. They should be ready tomorrow. I’ll up date the thread.

Halden I think have couple NA pumps and one turbo pump. One of the pumps as the wires for a Tach. I do not know the condition of them. Let me know if you are interested in the NA pump.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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I'm luving it
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Re: Glow Plug Check

Postby I'm luving it » Thu Oct 10, 2019 8:16 pm

New injectors picked up today and installed. Price for rebuild was $100 each at Seattle Injectors. That includes new tips, seals, and set pop off pressure. After removing old ones I didn’t notice any glaring issues with them.
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Installed was super easy and painless. I made the recommend tool from a 30mm deep well socket. Make sure it’s extra deep not just a normal deep well.
After install truck fired right up and no longer has the post start up smoke. Seems to run smoother and quieter.
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

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I'm luving it
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Posts: 254
Joined: Mon Apr 08, 2013 11:36 am
Location: Seattle, WA

Re: Glow Plug Check

Postby I'm luving it » Sun Oct 13, 2019 9:59 pm

After installing the new injectors I started getting white smoke at idle and thru the RPM range. So I figured I would check the timing since I have never adjusted it. I had it adjust a couple years ago but I always thought it was louder than it should be. So I bought a timing gauge on Amazon for $60. It was delivered today. After spending awhile figuring it out and reading the how to section on here It was easy. Hardest part was fi dung the dead spot on the cam. The timing was way to advanced. After setting it correctly 14-15 degrees it runs a lot better. More power and less smoke all around. Engine runs quieter. No matter how much fuel I give it there is no smoke. I am extremely happy with the results.
Here is the kit I bought.
4FC56749-2C54-4EB8-98FD-1A6AE9C67BA1.jpeg
-1981, 4x4, 5 speed, GT1548 Turbo diesel, long bed, Toyota axles, 33x10.50x15, 5.29 gears,

Eric Q.
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Location: Auburn, WA

Re: Glow Plug Check

Postby Eric Q. » Sun Oct 20, 2019 10:07 am

Nice work on all the maintenance items.
'75 body with '81 diesel running gear