real rough
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Hotshot
Joined: Oct 2003
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From: Here in No. Calif
real rough
If I don`t keep her plugged in she starts hard, bucking etc. I`m thinking GP or GP relay but I`m not getting any thrown codes. Talking about *30-*50 outside, when its warm starts normally. Ideas? Not a mechanic here btw
Lead Driver
Joined: Jul 2013
Posts: 9,266
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From: In the field...
Hank,
Just a WAG, but since it's not throwing codes I am guessing it isn't one single item failing but rather a few contributing factors at the margins of optimum performance.
30°-50° that does not seem GP related, but then again I've been wrong before.
Couple questions...
I am guessing you have done AIH delete?
What oil weight? Synthetic?
How old is the starter? Condition of batteries, age?
Just a WAG, but since it's not throwing codes I am guessing it isn't one single item failing but rather a few contributing factors at the margins of optimum performance.
30°-50° that does not seem GP related, but then again I've been wrong before.
Couple questions...
I am guessing you have done AIH delete?
What oil weight? Synthetic?
How old is the starter? Condition of batteries, age?
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Hotshot
Joined: Oct 2003
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From: Here in No. Calif
Always ran dino in it but Ill switch to rotella t-6.The batteries are brand new Cats 885ca
Mileage is 399476 on original GP and injectors. I did replace GP harness about 4 years ago. Thanks for help
Mileage is 399476 on original GP and injectors. I did replace GP harness about 4 years ago. Thanks for help
Posting Guru
Joined: Sep 2014
Posts: 2,404
Likes: 3
From: Asheville-where weird is
No prob. Hope it fixes the issue or if not, at least helps.
Do you have a way of monitoring voltage at key on? The B+ voltage should drop about 1-1.5 volts while the GP relay is energized. That can last for up to 2 minutes. If the voltage does not drop I would suspect the relay or wiring especially at nearly 400k. A relatively simple mod to rule out the GP relay is the Stancor Relay mod. There are great instructions on here and at the following link:
Welcome to guzzle's White-Rodgers (Stancor) GPR replacement Mod Web Page
Do you have a way of monitoring voltage at key on? The B+ voltage should drop about 1-1.5 volts while the GP relay is energized. That can last for up to 2 minutes. If the voltage does not drop I would suspect the relay or wiring especially at nearly 400k. A relatively simple mod to rule out the GP relay is the Stancor Relay mod. There are great instructions on here and at the following link:
Welcome to guzzle's White-Rodgers (Stancor) GPR replacement Mod Web Page
Posting Guru
Joined: Sep 2014
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From: Asheville-where weird is
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From: Here in No. Calif
Yes it is. I coulda sworn back then he said harness but heck as I get older I question myself
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Joined: Oct 2003
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From: Here in No. Calif
Is it hard to replace go module. Figure I could start there. Hate to throw $ at it but I need to start using more regular now
No codes still btw
Lead Driver
Joined: Jun 2007
Posts: 7,760
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From: Hampton, Maryland.
How many miles? If you have the GP module vs. the GP relay, it should be throwing a code.
If you have the module, it will be located passenger side of the valley towards the cab from the AIH relay. If you have just the GP relay it will be in a similar position and look just like the AIH relay in this picture.
If you have the module, it will be located passenger side of the valley towards the cab from the AIH relay. If you have just the GP relay it will be in a similar position and look just like the AIH relay in this picture.
It's a Van Gogh
Joined: Feb 2010
Posts: 7,813
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From: Elk Grove, CA
If the synthetic oil and mild temps (you're in Livermore, right?) are not cutting it maybe it's just time for injectors. 399k is a respectable service life. I think measuring the poppet clearance is pretty doable, from what I recall, and that will indicate how worn they are.
To test the GPCM stick a cheap volt meter like the one below in the cigar lighter and watch as you key the GPs on. If should dip about a volt if they are energized. If no dip, I'd surmise the GPCM is dead. If the GPCM was working a bad GP would throw a code for that GP.
To test the GPCM stick a cheap volt meter like the one below in the cigar lighter and watch as you key the GPs on. If should dip about a volt if they are energized. If no dip, I'd surmise the GPCM is dead. If the GPCM was working a bad GP would throw a code for that GP.
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