Setting the Cam Sensor

[TurboSlacker]

Help me understand this better...

If I take remove the cam sensor and reinstall it with the window point near the same direction when removed and the housing near the same oreintation when removed, the car should start fine, right ?

When I did this R&R my timing was off and the engine didn't turnover in a healthy way. So I set it the long way by putting the #1 piston at TDC, then placed the cam sensor window appx 4 o'clock pointing to the front-d/s, then rotated the housing to see the voltage drop from appx 7 volts to near zero. Engine fired right up.

Great, but I don't understand why I couldn't simply reinstall the cam sensor close enough since the only purpose of the cam sensor is to tell the ECM when the engine is positioned at compression stroke on #1 cylinder. The crank sensor should be telling the ECM precisely when to fire the ignition, not the cam sensor.

 

[LC2 ROD]

If you remove the cam sensor and install it in the same place without rotating the engine in between, than it should of had no affect. Why did you R&R the cam sensor?

 

[TurboSlacker]

I didn't rotate the engine with the cam sensor out. But why can't you be off by maybe 1 tooth gear? I would have thought that it's close enough for the ECM to recognize that the engine is near #1 TDC. I found it difficult to locate the cam sensor housing in the exact same location more so the locating the window opening. I guess next time I'll just rotate the engine to #1 TDC and set the cam sensor. Worked both times I've done it - just takes a little longer.

FYI, I removed it to shim cam sensor to reduce the up-down movement. Solved my very annoying, loud ticking noise I had. It was embarassing at idle.

BTW, if anyone wants tips on how to do this let me know. I used Moroso shim kit MOR-26140. Comes with metal washers .010", .020" and .053". Available thru Summit Racing, Jegs, Action Auto parts, etc.

 

[billsgn]

Cam Sensor tool....

Dan I have a Caspers Cam Sensor tool that you are welcomed to use....let me know.

 

[TurboSlacker]

Thanks, Bill. I simply use my voltmeter backprobed into the middle wire of the smaller connector to see the sensor is in the open window. I think this does the same as the casper tool or is it more clever ?

 

[billsgn]

It's more clever.....

Cause you are suppose turn the crank to set the cam sensor at 25 degree's AFTER top dead center. But your way works also. Just make a mark on your balancer 1.5 inches after the TDC mark (counter clockwise) and turn the crank to the "new" mark.

I hope this makes sense....

 

[LC2 ROD]

Originally posted by TurboSlacker
Help me understand this better...



Great, but I don't understand why I couldn't simply reinstall the cam sensor close enough since the only purpose of the cam sensor is to tell the ECM when the engine is positioned at compression stroke on #1 cylinder. The crank sensor should be telling the ECM precisely when to fire the ignition, not the cam sensor.

The crank sensor is sending a signal thru the ignition module for spark, but the cam sensor tells the ECM #1 cylinder position for spark and injector timing. Since the SFI dosent use batch fire, injector timing is more important. If you spray fuel late you can have fuel puddle at the valve and cause a very hard start condition. Or it could be something else, just a guess.