Help!
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Help!
I have a 1997 7.3 power stroke diesel with 130,000 miles on it. Last few weeks truck was having a hard time starting. Having to turn it over many times before firing it up. There was always a littlw white smoke at first. I changed the fuel filter and everything worked great for exactly a week. Just went on a 300 miles road trip and halfway through thr truck started shaking a lot and running rough both when driving and when idling. The normal diesel cackle is a lot louder now too. It took me forever to get up to 60 miles per hours and it wont accelerate up hills. Unless I'm driving down hill, I now can't seem to get above 20 miles per hour even with the gas pedal to the floor. I am not a mechanic and can't see anything obvious thats wrong. Please help with any suggestions.
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Fleet Mechanic
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From: Spokane, WA
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Hotshot
Joined: Jun 2007
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From: Austin, TX
Unless the DMF wasn't replaced, but was resurfaced instead. 
Not sure if anyone ever resurfaces DMF's, but I guess anything is possible. With the description of what the truck is doing though, I'd say probably burnt UVCH's though. Definitely check those out. You may even need to ohm them out if the outside pins look good.
Not sure if anyone ever resurfaces DMF's, but I guess anything is possible. With the description of what the truck is doing though, I'd say probably burnt UVCH's though. Definitely check those out. You may even need to ohm them out if the outside pins look good.
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So I checked the points on the 2 sets of plugs above each valve cover. All of the pins are shiny. None look burnt or bad. Since I had the big plastic cover off of the fuel filter can, relay, etc, I noticed one of the two large posts on the relay (the post furthest from the fuel filter), was very rusty unlike the rest. I went to looses the nut to polish it up and the post just spins inside the relay housing. Could this be the cause of my problem? This is the second time in 7 years I have replaced that relay.
Fleet Mechanic
Joined: Oct 2006
Posts: 1,386
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From: Spokane, WA
Unless the DMF wasn't replaced, but was resurfaced instead. Not sure if anyone ever resurfaces DMF's, but I guess anything is possible. With the description of what the truck is doing though, I'd say probably burnt UVCH's though. Definitely check those out. You may even need to ohm them out if the outside pins look good.
Not sure if anyone ever resurfaces DMF's, but I guess anything is possible. With the description of what the truck is doing though, I'd say probably burnt UVCH's though. Definitely check those out. You may even need to ohm them out if the outside pins look good.
Hotshot
Joined: Jul 2002
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From: Sheridan / Gilchrist
I went through a similar experience about 2 months ago. Everything seemed fine, then it seemed to suddenly want to run on 4 cylanders, the CEL would come on, but would go out and return to "normal" almost right away, several times before I could get radio volume down. Then one day, about 2 weeks into this, it just quit. I was dead on the side of the road.
We found 3 things that we fixed and were back on the road like new:
1. Replaced the CPS. That got us running, but with a rough idle.
2. Replaced the UVCH (all 4 of them)
3. Replaced the Glow plugs - saw a couple of "maybe" gonna be problems so just "cleaned" house while I was there.
We found 3 things that we fixed and were back on the road like new:
1. Replaced the CPS. That got us running, but with a rough idle.
2. Replaced the UVCH (all 4 of them)
3. Replaced the Glow plugs - saw a couple of "maybe" gonna be problems so just "cleaned" house while I was there.