Cam sensor issues/Guru's in general step in please!!

[Limited87]

Hi guys, I usually always can figure out these cars issues but this one has me thrown for a loop!!

Here goes.. I cant get this car to act right at idle UNTIL I unplug the cam sensor then its bascally fine. The car revs up and down irratically and will stall half the time like the cam sensor is bad. I have put 4 perfectly working cam sensors directly out of good running cars and set them up perfectly 25 degrees ATDC and nothing... they all do the exact same thing as the previous one. I have moved them little in both directions and nothing really changes..car still stumlbes and wont idle right.

It runs pretty decent at WOT but it doesnt seem quite perfect.

I have had several differant crank sensors in the car with no differance and 2 diff ecms and 3 differant MAF sensors, several coil pack and modules also! Nothing changes...

Car has 55# injectors, 206/206 billet roller, ported big valve heads, ported intake. Car has run 10.60@130

Any solid ideas what to try or what to check next or where to go from here??

Thanks

 

[DR BOOST]

check the ground wires on the back of the passenger cyl head.

 

[Limited87]

I just put this engine in the car.. it was basically doing the same thng in the other car but I figured I could figure it out in no time..so much for that idea.

I know there good and tight.. think I should add an additional ground cable to the block?

 

[corsair231]

TPS maybe??? That and vacuum leaks can cause major trouble.

 

[Limited87]

I have even changed complete throttle bodies.. I thought about the vacuum leak theory also but why does it straighten out as soon as I unplug the cam sensor is what has me thrown. You think it would have to do it all the type with a leak. I know it puts the car in batch fire mode.

 

[TurboDave]

I need to make an assumption based on some missing information in your original inquiry. One piece of info that seems to get left out of almost everybody's problem inquireis is: When did the problem manifest its self.

Has this been doing it ever since the engine was assembled? Is so, who degreed the cam and how sure are you of it's accuracy?

I'll assume you were positive that the #1 cylinder was at TDC on the compression stroke (not exhaust stroke) when you were setting the cam sensors.

 

[turbobuick]

Brian,
Its not a cam sensor issue. Car is lean at idle when you unplug the cam sensor it richens up the mixture when it goes into batch fire mode. This is a tuning issue or you have a vacuum leak somewhere. Give me a call this afternoon.

 

[TurboDave]

Brian,
Its not a cam sensor issue. Car is lean at idle when you unplug the cam sensor it richens up the mixture when it goes into batch fire mode. This is a tuning issue or you have a vacuum leak somewhere. Give me a call this afternoon.

I'm impressed! (seriously). You figured the issue out with such little information at hand.
If you're right about this, I'll be doubly impressed.

 

[Limited87]

Chris can u PM me your number been awhile and I dont have it. Thanks alot! Brian