No start problem.
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Senior User
Joined: Apr 2008
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From: Ont Canada
No start problem.
This is a question for my friends truck it is the same truck as mine except an 2003 model with the 7.3 he just bought the truck a couple weeks ago and it ran fine when he got it but then a few days after he picked it up it was having problems starting. once nevhe finally got it running he would be driving down the road and the truck would turn off or he would let the truck idle to warm up go in the house and come back out 5 min later and the truck would be off. so I told him today to go take it to the ford dealer to get the recall for the CPS and when he went they said it was already done on his truck. I told him to buy one anyone since there so cheap and put it in and the truck still won't start. also once the truck is running it run's really good. so any ideas let me know, thanks...
Hotshot
Joined: Aug 2006
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DTC P1668 and P1670 indicates that a communication error has occurred between the PCM and the IDM.
Possible causes:
Possible causes:
- Open fuse
- IDM relay
- Open or shorted IDM enable circuit
- Open/short in EF circuit
- Open/short in FDCS circuit
- IDM powering circuits
- PCM
Post Fiend
Joined: Mar 2007
Posts: 26,966
Likes: 50
From: Texas
Description
The IDM provides the EF output signal to the PCM to confirm that proper timing/duration of fuel delivery command signal (FDCS) was received. Additionally, the EF signal is used to send diagnostics of the IDM and injectors (electrical) to the PCM.
The diagnostic tree Rick referenced above lists lots of other things to check if any additional codes show up after running a KOEO self demand test. Can you run a KOEO test?
Has it rained there the last few days by chance? Any possibility some water got up around the IDM and is messing with the wiring?
The IDM provides the EF output signal to the PCM to confirm that proper timing/duration of fuel delivery command signal (FDCS) was received. Additionally, the EF signal is used to send diagnostics of the IDM and injectors (electrical) to the PCM.
The diagnostic tree Rick referenced above lists lots of other things to check if any additional codes show up after running a KOEO self demand test. Can you run a KOEO test?
Has it rained there the last few days by chance? Any possibility some water got up around the IDM and is messing with the wiring?
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Senior User
Joined: Apr 2008
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From: Ont Canada
Thanks for the reply's. It's just been off and on for the past week last week it wouldn't start and found a blown fuse for the fuel pump i think and then it ran fine for a few days then today having big problems with it dying while driving and not starting. we haven't had any rain this week so for his truck to get really bad today i don't think its water related but definately some sort of electrical problem.
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Senior User
Joined: Apr 2008
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From: Ont Canada
Well my friend is having some more problems, last week when i first posted this he found out the problem was a relay. He also put 8 new glow plugs in it since it was having problems starting when cold. well the truck ran great for the last few days and now is starting to have major problems starting when cold. It took him about ten minutes today for it to finally start and when it was turning over there was alot of white and blue smoke coming out the tail pipe. so any idea's for what makes it hard to start? and once it's running and warm it starts normal.
Post Fiend
Joined: Mar 2007
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From: Texas
Sounds like a glow plug issue. I realize he has new glow plugs and a new relay, but I would start by checking the GPR (glow plug relay). With a cold truck, check for voltage across the GPR to make sure the relay is good and there are no shorts in the wiring.
What ever happened with the blown fuse and the EF signal code? Those wouldn't be related to the glow plugs, and can come back to haunt you (him) if they're ignored.
What ever happened with the blown fuse and the EF signal code? Those wouldn't be related to the glow plugs, and can come back to haunt you (him) if they're ignored.
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Senior User
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From: Ont Canada
I think the fuse that was blown was for the fuel pump. it seems he fixes one thing it runs for a day or two then something else is going wrong. all these problems started when he plugged in his hyperchip programer into his truck while it was running, he didn't read the directions first where it says do not have truck running when plugged in. would that cause any of these problems from him doing that????
Post Fiend
Joined: Mar 2007
Posts: 26,966
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From: Texas
I think the fuse that was blown was for the fuel pump. it seems he fixes one thing it runs for a day or two then something else is going wrong. all these problems started when he plugged in his hyperchip programer into his truck while it was running, he didn't read the directions first where it says do not have truck running when plugged in. would that cause any of these problems from him doing that????
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