Good morning guys..... In mid fall , for my winter prep, I replaced my GPR and also tested my glow plugs. They all ohmed out good.I could start my truck without plugging it in with temps in the low 20's up until recent.
Now, my issue is, it hardly wants to start with recent temps in the 30's ! My question is.... Can all the plugs go bad at the same time? I ohmed them out yesterday, and they're all reading bad.
I know some will cite the harness coming undone, but wouldn't that also cause injector issues? I am fairly confident that they are the original plugs (13 years old), so I'am not complaining as I know I more than got my moneys worth.
More than anything just wondering if it is normal for all to go south a couple months after they ohmed good, or if I have another issue which caused it.
Thanks guys!

 

I'd check the GPR 1st - if you bought a "box store" GPR I wouldn't be too surprised if its already not working.

 

I would agree to that except for the plugs ohmed out bad. If my problem is a bad gpr, then wouldn't my plugs ohm out good ? Will go out and check it in a few, but I don't think I'll find it bad.

 

Maybe your meter isn't working correctly. Try measuring the resistance from the center pin to each injector.

G - G - I - I - C - I - I - G - G

G = glow plug
I = Injector return
C = Injector common feed

You should measure .5 - 2 ohms between G and ground, and around 3.5-5 ohms between I and C.

 

my gp's are all ohming out from .3-.385. When I checked them in the fall they all were reading between .8 and 1.4.I didnt check the injectors but I will. Is it possible the new gpr was too much for the tired glow plugs?

 

Put a new battery in your meter just in case. Can't hurt and then you can also test the old battery.

 

Sounds like your glow plugs are good then. The resistance will change with temperature. Try testing on a warm engine. The resistance should be higher.

 

Since my last post on this issue, I re-checked my 2 month old gpr again. I am now getting less than 1 volt on my multi-meter. It clicks on an off,so I am assuming pre gpr signals are good?
Now, upon opening the box of glow plugs the info sheet that came with it read as follows and I quote, "NOTICE--GLOW PLUGS DO NOT BURN OUT IN SETS.WHEN ALL SYSTEMS ARE OPERATING PROPERLY,GLOW PLUGS CAN ONLY FAIL INDIVIDUALLY! THE ONLY WAY FOR A COMPLETE SET FAILURE TO OCCUR IS IF THE CONTROLLER/RELAY FAILS, CAUSING UNCONTROLLED VOLTAGE OR UN-TIMED POWER TO THE GLOW PLUGS''
I know all my plugs are bad, and am now wondering if the bad gpr has caused my good in November plugs to be bad now.
My gpr ,from O'Reillys has a lifetime warranty, so I am going to try to get them to pay for my plugs provided I can convince them their gpr caused this.
I know they probably won't, but all the can say is no, right?
You guys think I have ground to stand on with my claim? Thanks

 

You say they ohm out at .3-.385. That is not bad as stated above. The lower the reading the better you are. Ideally you should see 0.00 That means no resistance and you had a good connection. The design of the glow plug will naturally have some resistance and that is what you see on your meter. Working glow plugs can read 6-10 ohms and still work fine.

Your GPR is no good and I would suggest you replace it. You can jump the large GPR posts with a screwdriver for a minute or so. Then I bet you the truck will start normally. LIke mentioned above, your GPR failed and that is quite common with non-oem parts. I know many believe the Stancor is the only way to go. I use Motorcraft GPR's and they seem to last well.

Here is a video I put together to show Glow Plug testing.

http://youtu.be/X7dAPNZD3t4


Also one on GPR testing.

http://youtu.be/zge6uHOPcn8

 

Thanks Ken... I was under the impression that too low of a reading as well as too high of a reading meant bad. But as I understand, you say a lower reading is what I want? If thats the case I stand corrected, and as you guys stated, my plugs are fine, its the gpr. Got to 15* last night, so off to do some gpr testing. Thanks again.

 

Get the stancore gpr. And are you still replacing the glow plugs?

 

Like said b4 you can use a jumper wire & jump across the 2 large terminals for a minute or two & see if it starts better for you. If it does this will verify that the gpr is defective. I would use a heavier piece of wire (8 or 6 gauge) as your jumper. Make sure to remove the jumper when done testing.

 

Negative. The worst case scenario was that the GPR stayed engaged until the plugs burned out. Nothing else the GPR can do would cause all your plugs to fail.

Don't be that customer most of us hate (we all know our trucks are ~ decade+ old). Lick your wounds, and get some new glow plugs (OEM) and then get yourself a Stancor GPR.

 

First off, great videos Ken. I looked at all of yours. Very informative, I had no idea about the serpentine belt keeper.
I too am having starting issues and tested my plugs and got 3 of the 8 that did not read anything at all. I assumed these are bad? The other 5 read between .9 and 1.4. What do you think? I'm planning on replacing all 8 this weekend. Is the general consensus still to use only Motorcraft plugs?

 

10-4 empire! I am not usually ''THAT'' customer, my line of thinking is as follows.
In my line of work, window and door installation, my job is just that,install windows and doors.......correctly. Not trying to argue ,but if I came to your house and installed a new entry door and 2 months later you developed a leak around the door somewhere, which in turn leaked into your finished basement destroying drywall, carpet etc., and this leak was a direct result of my shoddy installation, would you eat the cost for repairing the damage, or would you demand for me to have it repaired at my expense?
Now I realize the monetary difference, 100 bucks for glow plugs,compared to hundreds, maybe thousands for the water damage, but that really makes no difference.
I stand behind my work and I expect others to do the same when I buy products or services from them.
I understand I drive an older model vehicle, and I fully understand the repair costs of doing so, but because I do so doesn't make it right for anyone to sell me defective parts.
If something else on my truck caused the gpr to go bad, I accept that ,and will deal with that.
I asked for your'e guys opinion about my issue, and in doing so I am open to everyone's opinion and cannot be offended if I read something I dont like.
Therefore, I hope I didn't ruffle any feathers, especially yours Empire. You guys have helped me so much and I value your vast knowledge and you're sharing it with me!
Will I demand payment for the replacement plugs? Probably not! But if I do decide to ask, and they were to agree,which I know they probably won't, it would be a good day for me! Yeah for me! When they say no,not covered, at least I tried!