Glad it's fixed Chris. So odd that it caused the A/F to go haywire sporadically. Maybe it was intermittently working which prevented the tell-tale CEL light from clueing you in. I hope one of the pros comes on here to explain why these sensors go bad or does anyone know? Overheating? Anyway to prevent it?

 

Very nice to hear that it was a small problem.

 

raj, i have experienced this on my other cars. When you leave these sensors exposed to the elements(ie disconnected) there always seems to be a sensor or two go bad. In all my other experiences though the cel light has gone off lol

Also sharif also stated that it seemed once the car got hot enough is when the trouble occured. I guess heat was just causing some kind of resistance which would result in a faulty connection to the crank sensor.

 

that would be just about impossible for a backfire to destroy the sensor. the sensor is mounted on the bottom of the transmission. it reads a pattern of teeth that spins around on the flywheel.

sorry i am moving and have been soooo busy. i have a couple cars left at the shop to wrap up and then i am regrouping with a brand new Performance Factory!!! thanks everyone

 

A backfire wouldn't hurt the sensor. Most of the time the sensor is damaged when removed or left in place when a clutch & flywheel are done. This peice of electronics is a little more sensitve than most believe. The damage was most likely done when the car was in the shop.

 

you are absolutely correct. we actually play a little game with all the cars that leave our shop and put ONE bad sensor in. then we make bets between ourselves for the amount of time it takes for the car not to run right.

i won $200 dollars on chris's car!! pretty excited about it, he almost made it all the way home....

 

JT don't be a moron. Maybe if you read and comprehened what I wrote you would understand instead of being defensive and trying to start a fight. Go back and read what I wrote in his other thread about this problem. All you said was not my fault and it's not the F-con it left the shop Ok. I guess it was the OP's fault. Stop messing up his thread with your BS or if you have a problem take it PM's.

 

good stuff Chris! Hopefully the weather cooperates and you get some seat time now, and smooth sailing!!!

Not the first time I've seen a bad sensor on a Z and not get a specified code for it (remember my coil issue a few weeks ago?). I'm happy to hear it didn't require major surgery to diagnose and fix. Diagnosing these types of problems can be a royal pain in the rear, but you're not new to the game, so you know the deal. Modern technology often clouds our view and we think the issue is more elaborate than it sometimes is. Sometimes it just takes a fresh set of eyes and a clear head to sit down, and going back to basics.

 

Crank and cam position sensors are notoriously sensitive devices. Ever wonder how the ECU knows you have a "random cylinder misfire"? The crank position sensor is detecting an abnormal acceleration of the flywheel (results from incomplete combustion in 1 cylinder)....a flywheel that is spinning at 1000-7000 revolutions per minute, or 17 to 116 revolutions per second. That takes some serious precision to detect that! The service manual indicates that if you drop the crank or cam positions sensors from more than 2-3 feet height, you should discard them. They are very sensitive to shock.

We also carry a couple spares to the track, incase one decides to take a dump.

Yup, glad it was an easy fix...but unfortunately it still takes time to figure it out.

 

Glad you are all fixed up Chris, these problems can be very frustrating but its just part of the game.

Now go enjoy your car!

-George

 

Great information! I never realized that the crank position sensor dealt with that amount of data with that much precision...

It almost seems like a miracle that they every work... not that they fail once in a while.

Here's a little blurb from the FSM if any of you are interested.

 

great read! chalk that one up to experience and next time people can check that sensor sooner!

 

Good data - learn something new everyday - thanks Sharif and jb!