When cruising down the road at a constant throttle position the motor will suddenly boost real hard for a split second and then go back to normal for no reason. The check engine light will then come on for about 30 seconds and go back off again. I had advanced auto scan it for me, but no code. I also can feel it boosting up ever so slightly and then off again when the motor is under a bit of a load with the throttle at a constant. So it's coming on and off while driving now as well, but not all the time.
I know it has to be something to do with the turbo wastegate actuator sticking maybe,vacuum leak, or an electrical sensor that actuates the actuator. I have never been elbow deep in a 7.3L powerstroke before so I don't know where to start. I want to fix this myself and any help on this would be greatly appreciated.
Welcome to FTE. Go get that code checked from somewhere that knows what they are doing. Advance doesnt have the tools needed to scan a Powerstroke. Look for a buddy that has a program or tool like a snap-on scanner, or Autoenginuity. Or a buddy with something like a superchips or diablo tuner, that can pull codes for you. I'm betting it is something like the Injection Pressure Regulator valve sticking when you are easing into the pedal, when it sticks a little more closed than it should be, causing more fuel to be given, giving the surging feeling. The turbo has nothing to do with it, wastegate whatever, it only spools up and lets off for a little bit because it is being fed more fuel (energy to spool it). Im betting you have some code that is P12xx.
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Thanks for the info brotha! That totally makes sense what you are talking about. I'm suppose to bring it to the dealer on tuesday to get the code read and I know they are going to try and take me to the cleaners. I know I could fix the prob myself if I knew what it was. I'm also screwed in the fact that I just moved up here so I have no friends in the Appleton, WI area that I could ask to scan my 7.3 for me.
Now that i think about it, the other day I took off from a stop light and the dam thing took off like a bat out of hell. It had more power then it's ever had before like the wastegate was stuck closed. That tells me right there that it's got to be something with how the wastegate is controled. If I pull the vac line off of the wastegate actuator will it fail in the open or close position?
This is a suggestion concerning the IPR (injection pressure regulator). Pull the connector off the ICP (Injection control pressure) sensor. The PCM will go to a default setting. Drive your truck and see if the surging is still there. Remove this connector with key off and replace with key off just to be on the safe side.
The default gat positon is closed. Also, FWIW, it is not vacuum operated it is pressure operated. Even with the red tube removed, the truck will defuel at 22-23 psi boost. When it defuels you will get an SES light for a few mintues and an overboost soft code.
Check your lines/connects to the map sensor, and the red line for cracks/leaks/defects. These are things in the "control circuit" for the wastegate.
Well, i took it to the stealership and there was a code with something about the ICP sensor is not reading. I told them i would put the new ICP senosr in and see what happens. They said the harness could be bad as well so i'm gambling with just replacing the sensor. Would the ICP sensor not picking up cause my symptoms? Sucks cause it costed 98$ to get a dam code checked and a new sensor is $166.00
Anyone know where on the net i can get a diagram of the 7 3 to see where this sensor even is? Thanks for all your help!
The sensor is located above the driver's side valve cover, on top, toward the front of the engine. Look directly across from the fuel bowl and you'll see it, I want to say it has 2 wires. It takes a 1" or so deep socket to remove. Very easy to access. Like Robin syas in post #9, one you locate it, unplug it and see if your problem goes away. The PCM has a default pressure table built in just in case the ICP fails. If it is a bad sensor, and you unplug it, the truck will drive absolutely fine. It will also throw a code when it detects the sensor "missing", not to worry, just expect/remember it.
If you need a new sensor check to e-bay. You should be able to find an new one for $50.
Yeah i just bought one for 70$ on e-bay. Thats was the cheapest one. Only problem is that i'm selling the van on e-bay and i have to fix this before i sell it. I don't know how long it will take for the sensor to arrive. So if i unplug the ICP tonight while i'm waiting for the new sensor and my probs go away then it was the sensot right? what is the PCM?
If you unplug it and it goes away, it certainly points strongly to the ICP being the problem. I had with a fluctuating idle that turned out to be the ICP. With the engine runnning, and flucuating, I could unplug the ICP and it would smooth out immediately.
PCM is the Power Contol Module (or something along those lines) it is the main computor.
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