Hey yall, I am having some trouble starting my 1999 7.3 when it gets below 25 degrees and need some help figuring it out. My GPR was bad and so I replaced that and it still has a lot of trouble starting. The truck will not crank for awhile and then if i get it to start it will lope for at least 15 to 30 seconds before running at an idle. I checked the olms of the glow plugs and they are all reading 0.0. I read that they are supposed to be between 0.5 and 2.0. Does this mean the glow plugs are bad? I also checked to see if power was coming to the glow plugs when the key is turned and they are receiving about 11 volts. If you have any ideas I would appreciate it. Thanks in advance

 

0.6 to 2.1 ohms is right for a new glow plug. Was your meter set to its lowest ohm range when you were testing them? It doesn't seem like they could all be open circuits. I suppose it's possible; seems unlikely though.

 

Aren't they supposed to get full battery voltage? If so it should be closer to 12.3 volts. But if you have two or more failing GP's it will be really hard to start if at all.

 

When it doesn't start, are you getting a bunch of white smoke while cranking? As in, smokescreen can't see the neighbors house amount of smoke?

 

0.0 (dead short) for every one seems strange. Can you double check that. If there's really a short you need to find where it is.

 

Yes, dead short. That's what I meant above rather than open (duh). My bad.

 

When the glow plugs are active, that's a lot of amps. It will drop the battery volts below 12 until the GPR cycles off.

 

Thank yall for the help, you were right about the multimeter. I had it set on autorange. I changed that to the lowest setting and now all the glow plugs are within the 0.6 to 2.1 range. All the glow plugs must be good as well. My batteries are reading 12.3 volts and then when the key is turned the glow plugs are receiving 11.2. I am going to go get my batteries tested tomorrow and see if there are any cells messed up and see what the cold cranking amps are at. And as far as smoke, there is a good bit of white smoke but it aint thick enough where you cant see through it. Any other ideas?

 

I've been beating this drum lately, and I'm sure a regular or two may find this as a cue to click the next thread. Everything on the whole GP system can check out externally, but that does not automatically mean it will work as designed. The problem is glow plugs lose their oomph over time/cycles, so the final test is to pull one out and apply 12 volts with jumper cables. You can then compare the reaction with videos found on YouTube.

 

What kind of oil are you using? I decided to try some T6 synthetic on my last oil change and this is my second winter with the truck. It's night and day difference between starting and help with the romps.

 

my 02 just started doing the same thing. of course it is plowing season, and i can't take it apart now so i just plug it into a switched outlet and turn the block heater on 2 hours before i go out.
i will just have to live with it until spring time when i can lay the truck up for a week to change the glow plugs and get the injectors rebuilt.