Cam Sensor Problems?

[gnmike87]

Does anyone know any possible reasons my car will only run if I take the cam sensor out and move the window clockwise around 6-7 a clock? I know the timing on the motor is fine because a couple of weeks ago it was running just fine with cam sensor at 4 a clock and adjusted per instructions. The only change to the car since then has been a new turbo, ported heads, and T&D roller rockers. Any ideas would be greatly appriciated.

Thanks
Michael Merrill

 

[mybuick]

it is supposed to be at 7 o'clock with the engine at 25* before tdc... look into the caspers cam sensor tool.

 

[gnmike87]

I always thought and have always set mine to 4 o clock and 25 degrees ATDC. If I am wrong here the car has always ran, not always correct but sometimes :smile: .

 

[mybuick]

i would think the car would be slow since the engine is on the power stroke before the spark plug fires. you should feel alot more power set the right way...

 

[gnmike87]

Hehe not only is it slow it won't start. I will try setting it 25* btdc and dropping it in at 7 o clock, except I think that 25* ATDC with the window at 4 o clock and 25* BTDC and window at 7 is the same thing. I have tried everything else so I will give it a try. P.S. I have a cam tool if I can find it.

 

[mybuick]

see it this way the crank rotates clockwise at 12 o'clock on the crank is tdc (0*). then 11 o'clock would be 25*btdc (compression stroke) and 1 oclock will be 25*atdc (power stroke) that is how btdc and atdc is looked at.

 

[gnmike87]

I will give it a try tommorow morning as I am sure my neighbors would not appriciate me starting it through an open downpipe tonight. Thanks for the info I will let you know if I find something tommorow.

 

[87 turbo buggy]

cam sensor

when the cam sensor seens to have moved without no reasion, i would think to check the timming chain.. mark the damper at tdc rotating it in a clockwise rotation to line it up. then rotate it to the left [counterclockwise] and see how much of a return rotation is needed to make the cam sensor move the other way. a few degrees is acceptial. more than a few degrees, less than 5 degrees, any more the chain is worn out. replace it with a good chain and lower and upper gears. use a set it is thr best way to go.

 

[gnmike87]

The motor is brand new along with everything in it. The timing chain is a double roller. I would hope it has not jumped time in 200 miles.