Electromotive crank sensor location

It sounds like a problem with the tach itself. If you have an oscilloscope or know someone who does you can check the signal going to the tach to be sure the signal is good but I think you’ll find it is.

The problem is not the sensor, if it were the engine would cut out as well as the tach. As for the position you could mount the sensor anywhere really, personally I tend to put the pickup and sensor on the flywheel end.

 

Tach needs a pulse train, and doesn't care about where in the 360 degree cycle of the engine these pulses come exactly. I agree with Mark that this is most likely a tach problem. You'd definately notice a sensor problem in the way the engine is running!!

Where along the 360 degrees the sensor is located doesn't matter either, as long as you adjust the toothed wheel to match the sensor location! Think about it: if you both rotate them 240 degrees clockwise, your sensor will see the exact same teeth at the exact same moment.

And Mark, for those who are slightly less at ease with pulling an engine, I guess the accessory side of the engine is a lot more accessible to put a sensor in with the engine still in the car...

Since I am probably going to go EFI with mine too: why would you prefer the flywheel side? (trying to figure out the BEST location for a sensor, not the EASIEST)

Thanks!

Hans

 

Who are you and what have you done with our beloved “Carbs rule!” Hans!




To get to the flywheel on a 308 you just pop off the bell housing, no need to pull the engine.

I prefer the flywheel end for 2 main reasons. First is everything is protected inside the bell housing. Second is the flywheel isn’t going to move relative to the crank and will never require re-timing of any kind.

I don’t have any strong objection to mounting on the front of the engine other that the wheel is exposed. I don’t care for setup that clamp on the outside of the damper because the rubber does let it move around some but I’m not sure how much it really matters.

 

My crank sensor is nearly at the same location. If you have a stock tach, you most likely have a seperate "box" that controls its imput. Check that out. Also, gounds are critical. Make sure all your grounds are clean and solid, including the ground strap from the engine to frame near the crank. (You would yourself a good deed if you remove that ground strap and place it near the starter..hint, hint).

 

Carbs certainly rule over Bosch K-jetronic.

EFI rules over carbs. Especially when you try to keep the voodoo Gods of Weber Tuning away!

Bottom line: one of my Webers is shot - someone twisted a CO adjustment screw in at an angle. And so the carb needs replacement, as I'm running 7 times a 50 and 1 time a 56 idle jet in order to get it running anywhere near okay at the moment. No thanks! With the progression holes seemingly different for every carb you get, even for the ones with the same serial number, the webers are effectively a matched set. 4 webers equals more money than a complete EFI setup. And still, I'd have to get them tuned properly then...

When replacing the webers by weber shaped throttle bodies, I reckon I'll have the exact same air path, and thus airflow and thus wonderful sound. I can just program rather than fiddle the correct amount of fuel in. Heck, I could even program the flame spitting on the over-run in my fuel maps!

Good points on the position for the crank sensor. Where do you mount it to then? Happen to have some pics somewhere?

Thanks!

 

The 308s I've done have all been former CIS cars, so I just used the stock pickup location and either added more pins to the flywheel of mounted a trigger wheel to the back of the flywheel.

I'll see what I can find for picture....f**king windows vista seems to show me pictures in completely random and unhelpful ways and I can never find anything I'm looking for any more unless I've thrown them on an external drive that windows doesn't or can't organize for me. Whoever thought this up deserves the Dumb*ss of the year award. I'm not a vista fan if you haven't noticed...it makes office 2007, which really s*cks, look better in comparison though guess.