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Gpr or flow plugs?

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Old Aug 18, 2016 | 02:02 PM
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From: reedsport
Gpr or flow plugs?

My truck just started taking 4-5 seconds to fire up. But still starts every time. Do I bother testing gpr? I can't find a post on bad gpr symtoms. Thanks
 
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Old Aug 18, 2016 | 02:20 PM
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From: Bahstun
You can ohm out the glow plugs at the UVCH plug and then see from the controller if there is 12v being supplied from that connector
 
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Old Aug 18, 2016 | 02:27 PM
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At these temps I don't think that glow plugs will be the issue but I have the same problem and would like to hear what you find.
 
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Old Aug 18, 2016 | 02:34 PM
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From: Bahstun
Vallejo had some 54 degree mornings coming and that might need the GP to work right


at 70 I don't wait, just crank it over with out issue just like I have done on my diesel tractor for past 10 years.


If the starter is getting weak and slower, it might not get enough cylinder pressure to combust the fuel


worn injectors can retard the timing and make for a hard start but test the GPs first and let us know the temp you were trying to start it at
 
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Old Aug 18, 2016 | 02:42 PM
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Bad injectors can cause hard starts , it could be 100° outside and still won't start.
 
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Old Aug 18, 2016 | 02:47 PM
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From: reedsport
Ok. Will test glow plugs when off work
 
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Old Aug 18, 2016 | 04:01 PM
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From: reedsport
All glow plugs have resistance. All at .5 to .6 except second plug from rear on passenger side. Was at around 26.0. I guess that's the culprit. Runs fine as well once started. Motor cranks normally. Just takes those extra seconds to fire up.
 
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Old Aug 18, 2016 | 04:52 PM
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1 plug shouldn't slow that thing down a bit. Something else is going on.
 
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Old Aug 18, 2016 | 04:55 PM
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From: reedsport
Originally Posted by HKusp
1 plug shouldn't slow that thing down a bit. Something else is going on.
No engine light or codes. Batteries 2 years old. I wil
Google how to check gpr and see what comes up.
 
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Old Aug 18, 2016 | 05:11 PM
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i always put a light on the outlet of the glow plug relay. i have started using 12 volt LED's the past year. this rules out any question whether the relay is working or not. .if the LED/light comes on, the relay is working.
the dash wait to start light will come on for 15 seconds or so whether the relay is working or not. with the added light, you will see the glow plug relay actually sends power to the glow plugs for up to 2 minutes.
 
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Old Aug 18, 2016 | 05:42 PM
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Originally Posted by tjc transport
i always put a light on the outlet of the glow plug relay. i have started using 12 volt LED's the past year. this rules out any question whether the relay is working or not. .if the LED/light comes on, the relay is working.
the dash wait to start light will come on for 15 seconds or so whether the relay is working or not. with the added light, you will see the glow plug relay actually sends power to the glow plugs for up to 2 minutes.
Not trying to hijack but I been wanting to do the GPR light mod and was curious if we have a wire schematic or Anything like that posted up to here?
 
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Old Aug 18, 2016 | 06:28 PM
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Signature states Vallejo ( CA.?) = GPCM, different ball game. Need to check for power to each GP, or could be a whole bank.
 
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Old Aug 18, 2016 | 06:32 PM
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From: reedsport
Originally Posted by hydro man 17
Signature states Vallejo ( CA.?) = GPCM, different ball game. Need to check for power to each GP, or could be a whole bank.

Where is gpcm located?
 
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Old Aug 18, 2016 | 06:55 PM
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From: reedsport
With ignition off I get battery voltage on positive side of relay. But I get 37.7 volts off the other side of relay with ignition off. With key on I get batt voltage on batt side post and 9.62 volts on other side big post.
 
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Old Aug 18, 2016 | 08:06 PM
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Do you have the glow plug relay or is your truck an original California truck with the GPCM?

If a relay equipped truck check this thread. lots of good stuff from Roland and Rich about testing the relay.

https://www.ford-trucks.com/forums/1...y-strange.html
 
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