Defueling issue, HELP!!!!

Rodram2002

Rodram2002

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May 8, 2007
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I have been fighting a defueling issue for some time now. The truck will lose the tack signal from the cam sensor and de fuel. I have found part of the issue. The gap between the cam and the sensor should be 0.020-0.030". Mine was 0.175" :doh: I have shaved the sensor to get the gap at about 0.030" now. The truck would always throw a P0341 code for the cam sensor. Now it wont throw that code any more. It will miss and spudder at idle and now is throwing a P1690 code for the Crank case position sensor. How is this? My truck does not have a crank case position sensor. I have called a few shops and none have any idea what is going on with my truck.


Might any of you have an idea what is going on and how to fix it?

Scotty.
 
What do you mean you shaved the sensor????

All you have to do is loosen the 2 bolts on each side of the sensor and slide a buisness card undering and then tighten it back up.
 
2 bolts? mine is held on by just one bolt...and I dont see how shaving it down would help as the sensor and hole are concentric.
 
The sensor has only one bolt holding it in place. I shaved the mounting surface on the sensor so it would protrude farther in toward the cam gear as to get the correct gap.



My main thing right now is how can my truck throw a code for a sensor that isn't even there?????? I have no crank case position sensor.
 
Fishin2Deep4U said:
Still fighting it Scotty?

Is that the original ECM?? I can't remember.

Dave
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Still fighting it Dave.:bang I am running a replacment ECM, Hoss has my old one and I got his no cruse control one that I offered you at Fast.

I got the cam sensor at the correct depth and it works well now. I don't think the truck is defueling now, but it throws a 1690 code like crazy and misses at idle. There doesen't seem to be any thing that sets the code off. I clear it and the truck might set it right after I start it when ideling or 10 minutes later doing 65mph down the road. I just don't get how setting the cam sensor to the corect depth brings this problem up when I never had it befor. There are no other things like dead pedal saying it's the apps or VP, so I'm kinda lost at the moment.
 
What year did the replacement ECM come out of? Was it the same year as yours? I am getting my hands on a loaner this week.

Dave
 
Fishin2Deep4U said:
What year did the replacement ECM come out of? Was it the same year as yours? I am getting my hands on a loaner this week.

Dave
Click to expand...

It was out of a 2002.

So, I just went an put 6 dyno runs on the truck and still only making 544hp. It seems every time I dyno now, the truck makes less and less hp. Most of the runs were smooth and the truck threw no codes for the dynos.

Dave, I'm thinking our trucks might be twins.:doh: Max power was always close to 2500rpm and then held for a few and droped off from there.
 
Yeah, no kidding.

Mine spins to 2450-3500 and flat lines. Makes over 500HP until I lift.

My issue is obviously a clipped fueling limit. It gets so much and it gets no more. But I don't have any codes.

Dave
 
You've got the problem I've got. Truck is set up perfect but it keeps going less and less. I've gone from 496hp down to 375hp and the only thing I have left to replace is the ECM. I'm gonna have mine reflashed.

Are yall hitting the speed limiters? I know before the smarty speed limiter program I would hit the speed limiter on the dyno far before finishing the run and it would flat line my dyno curve. You could feel the truck pulling real hard and then suddenly nothing.
 
Fishin2Deep4U said:
Yeah, no kidding.

Mine spins to 2450-3500 and flat lines. Makes over 500HP until I lift.

My issue is obviously a clipped fueling limit. It gets so much and it gets no more. But I don't have any codes.

Dave
Click to expand...

I just talked with Byron and he mentioned, my low numbers started arounf the same time I upgraded my smarty to the Beta 150mph version. I swapped it back to the original program to see if it might help.
 
BgBlDodge said:
You've got the problem I've got. Truck is set up perfect but it keeps going less and less. I've gone from 496hp down to 375hp and the only thing I have left to replace is the ECM. I'm gonna have mine reflashed.

Are yall hitting the speed limiters? I know before the smarty speed limiter program I would hit the speed limiter on the dyno far before finishing the run and it would flat line my dyno curve. You could feel the truck pulling real hard and then suddenly nothing.
Click to expand...

I don't think the speed limiter has ever been a problem for either Dave or me as we dyno in direct and only make 90mph or so. I can see that being a big issuew if your wheel speeds are getting close to 110mph or over on the dyno. I have hit the speed limiter several times and now the feeling. I am sure that isn't my issue.

I have tried changing the VP, tried 4 different boxs, 2 different ECMs, a few sensors, chasing alot of wires and still haven't come up with much.
 
I've also wondered about the beta program but mine started before that and I know guys with the beta program that don't have the problem I'm having.

On a dynojet I usually dyno in OD. One thing I do know is that I remember reading a while back about a TSB for low power in OD. Don't know if that would affect you but it's something I'm gonna look in to.
 
BBD, I would try dynoing in direct and locked up if you can. I thing that should help with the speed limiter issue. I asked Bob for the ECM recovery he sent you just to rule things out.
 
He ain't sent me anything yet. I've emailed him and pm'd him. I'm gonna call him tomorrow. I've always been told to dyno in OD on a dynojet.
 
Dynoing in OD makes sense to load the motor more, but if you are going to defuel because the speed limiter, then what good does OD do for you?
 
True. I ain't got that problem anymore with the speed limiter program though. She pegs 120mph around 2700rpm and keeps on pulling to 3500.
 
Yeah, normally dyno in OD as well. At 2500 rpm, that's only 96 mph.

Most trucks make peak power up around 2750 or so and that's around 106mph.

At 100 mph my trucks just quit making power. Doesn't fall off or defuel, just stops building.


Speed limiter should not be the issue. To test, I have tried a BD RAd as well. No change.

I am trying to find a Redline to rule out the VP and send my search back to the electronics.

Dave
 
Rodram02. Not to derail your thread, but do you get a "VIN Mismatch" code now that you swapped ECM's? I put a used one in and I get that error and my ABS and Brake light won't go off. All other codes are clear. I know the VIN in the PCM is correct and I didn't think the ECM held a VIN.
 
4x4dually said:
Rodram02. Not to derail your thread, but do you get a "VIN Mismatch" code now that you swapped ECM's? I put a used one in and I get that error and my ABS and Brake light won't go off. All other codes are clear. I know the VIN in the PCM is correct and I didn't think the ECM held a VIN.
Click to expand...

I have had 4 different ECM's in my truck and never had that happen. All have been programed for a 2002, if you are using one for a different year it might do that I guess.
 
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