GP Test results

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Dec 9, 2006 | 11:20 PM

Olddog66

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Senior User

Joined: Sep 2006

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GP Test results

I got under the hood and tested my glow plugs today with my meter, here are the results:

7 – 1.0 ohms

5 - Open

3 - .8 ohms

1 - .9 ohms

<O

8 - .8 ohms

6 - .8 ohms

4 – 1.0 ohms

2 - 1.0 ohms

<O

Why does my truck have such a hard time starting when it’s cold if only one plug is showing open? I get the white smoke and the off balance engine symptoms…I fully expected two or three to be open. I took the intercooler duct off the left side just to get a better shot at the plug/injector harness. Is it possible to get that thing out of there in order to pull the valve cover? It was like a twisted piece of spaghetti wrapped around a corkscrew! I’m getting scared about replacing number five after reading about how the tip of the plug can potentially fall into the cylinder…what are the odds of me turning a cold start issue into a larger one?
<O

Last edited by Olddog66; Dec 10, 2006 at 12:07 AM.

Dec 10, 2006 | 12:54 AM

kbeefy

Cargo Master

Joined: Aug 2003

Posts: 2,332

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From: Eastern Washington

is your gpr working? (have you tested it?)

Dec 10, 2006 | 04:59 AM

ponch37300

Laughing Gas

Joined: Feb 2006

Posts: 947

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sounds like a gpr issue if your gps are fine minus one. I replaced my gps a couple of weeks ago since i don't have anywhere to plug it in at night with single digit temps and i just wanted to make sure they didn't have any problems and they were only like 8 bucks a piece at autozone for the motorcraft brand. Still had a ton of white smoke so got a gpr. If your gps ohm out besides that one, the gpr isn't sending enough power to all of them. I got mine from http://www.discountfordpartsaty2kford.com/ for about 65 bucks shipped and is a motorcraft oem part. You can test your gpr by jumping the two big terminals with a screw driver for about 20 second(when the engine is cold) and see if that helps with the white smoke. If it does help, then it is your gpr.

Last edited by ponch37300; Dec 10, 2006 at 05:08 AM.

Dec 10, 2006 | 06:49 AM

Kwikkordead

Fleet Owner

Joined: Jun 2004

Posts: 25,090

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From: Rio Rico, AZ.

I agree, it sounds like the relay is dead.

Dec 10, 2006 | 07:57 AM

Olddog66

Thread Starter

Senior User

Joined: Sep 2006

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Gpr

I tested the GPR and I got 11.5 volts coming out of it when my wife turned the key. Could it still be bad?

Dec 10, 2006 | 09:24 AM

nodakford

Senior User

Joined: Oct 2004

Posts: 376

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From: South Dakota

Sounds like the relay is working. Your glow plugs are getting weak excepts for #5. #5 should have some resistance, .1 ohms at least. New glow plugs that I put in had .1 ohms. Pulling tha glow plugs isn't as bad as you think. I bought the tool to help, in case the glow plug was stuck, but never used it. Just a 10mm deep well socket. If you wanted to wait till a warmer day to change them, don't start the truck right after the light goes out, wait another 30-40 sec. and that should help, along with plugging it in.

Dec 10, 2006 | 02:09 PM

kbeefy

Cargo Master

Joined: Aug 2003

Posts: 2,332

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From: Eastern Washington

#5 does have resistance... it's infinite resistance (at least infinite in relation to the amount of current your multimeter is capable of). Thats what they do when they go bad. They also show that when the wire breaks or comes unhooked. Reguardless, the valve cover needs to come off.
As noda mentioned, they should stay hot for a while when it's cold outside, wait a minute after turning the key on before starting it.
Where did you check the GPR? Both big terminals should show battery voltage when the trucks cold and everythings working. And you checked the rear relay, right?

I don't want to get my pointer out again but I will if I have too! It's getting alot of use lately...