rough idle when hot getting worse
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From: new jersey
rough idle when hot getting worse
Anyone got it figured out yet. I have read about a lot of fixs. the local injection shop say low press. from the VP44 is most likley the cause 
and to drive it till it needs to be towed or codes out. But its been doing it for about a year now and I think its somthing other then the VP44 its never coded, the fuel pressure is good at 13 idle 10wot, it seems to be getting worse in the last week or so as soon as the eng. temp. starts to go up it starts the miss. my clutch fan is good, it never overheats even pulling 8600lbs
and to drive it till it needs to be towed or codes out. But its been doing it for about a year now and I think its somthing other then the VP44 its never coded, the fuel pressure is good at 13 idle 10wot, it seems to be getting worse in the last week or so as soon as the eng. temp. starts to go up it starts the miss. my clutch fan is good, it never overheats even pulling 8600lbs
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I would test the IAT sensor and the engine coolant sensor and be certain they are clean and properly functioning. Either or both can be faulty and not result on a code being set.
The other thing to do it to run a really good injector cleaner through the rig and see if that eliminates the miss. We are at the time of the year that refinery run batches are being changed, and someone always gets the tailings from the seasonal storage cleanout.
Another tip is to add 2.5 ounces of Acetone to each ten gallons of diesel in the tank, and use the truck for a while. If the miss goes away in a few miles, it was water in the fuel. If the miss returns after the treated fuel is exhausted, then it is dirty injectors. Acetone breaks the surface tension of the fuel and allows it to vaporize much better.
The other thing to do it to run a really good injector cleaner through the rig and see if that eliminates the miss. We are at the time of the year that refinery run batches are being changed, and someone always gets the tailings from the seasonal storage cleanout.
Another tip is to add 2.5 ounces of Acetone to each ten gallons of diesel in the tank, and use the truck for a while. If the miss goes away in a few miles, it was water in the fuel. If the miss returns after the treated fuel is exhausted, then it is dirty injectors. Acetone breaks the surface tension of the fuel and allows it to vaporize much better.
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From: Fort St John BC Canada
rough idle
Well I suspect that you have what I do on a 99. 
Do you have accesss to a multi meter that has frequency on it if so put it on different spots PDC out put from the Alt etc. See what it registers mine are from 22 to 103 HZ.This is very bad.
Does run rough from idle up to 1400 ??? or to full throttle? Mine is bad at 1100 to 1275 where the fuel shut off won't let you run the engine at this position. Any way does it pound at any of these speeds???? If so get back to me and I can help more maybe will give you more info.
Do you have accesss to a multi meter that has frequency on it if so put it on different spots PDC out put from the Alt etc. See what it registers mine are from 22 to 103 HZ.This is very bad.Does run rough from idle up to 1400 ??? or to full throttle? Mine is bad at 1100 to 1275 where the fuel shut off won't let you run the engine at this position. Any way does it pound at any of these speeds???? If so get back to me and I can help more maybe will give you more info.
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From: new jersey
Whats a PDC do you mean PCM power control module? If so thats new. I have new injectors.Only thing that are not new are the ECM and the VP44 I will changing VP44 as soon as I have the funds
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From: The Great White North
Terry, hes talking about the Power Distribution Centre (fuse box/breakers next to the drivers side battery).
My guess is that the VP-44 may be borderline....do you have a OBDII code reader??
My guess is that the VP-44 may be borderline....do you have a OBDII code reader??
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