MX-3.com

Help! I've got a 92 MX-3 that starts, comes up on fast idle (1500 - 2000 RPMs), then dies. The fuel pump is putting out good pressure and the the spark seems to be good. I did the module mod, but still have the same problems. The diagnostics show a consistent cam position code (03), but I had an Acura that did that even though the cam sensor was good. Are there any good ways to test the cam sensor or am I stuck with replacing the distributor just to see if that fixes it? Thanks for any ideas you guys have!

A shop can test the sam sensor, but the V6 has two. Both called cam sensors eventhough one senses the crank not the cam. You'll see it right next to the crank pulley, it is facing the crank position wheel. That could be the one that is not working.

Do you have the V6 K8?

I have nowhere near the expertise of Pat, but I have recently gone through the replacement of the Crank Position Sensor. This is the one by the crank pulley. I was getting code 02.

With this code I was getting some weird idle and some hesitation when accelerating in 1st gear from idle. The car was also running rich. But in general it was driveable. Apart from the messiness of getting the pulleys out of the way to remove and reinstall it was actually a pretty straightforward job. Immediately addressed the CEL code and driveability.

I think the Cam position sensor in the Disty is more crucial. eg lacking a sensor input from the Crank Position sensor it just defaults timing and fuel air mixture , but I think the camshaft sensor in the disty could really mess up ignition.


Section F2 on Fuel and Emission Control Systems, K8 DOHC (if you have the V6) on page F2-153 in the online shop manual is a good place to start.

Sewer Rat wrote:Help! I've got a 92 MX-3 that starts, comes up on fast idle (1500 - 2000 RPMs), then dies. The fuel pump is putting out good pressure and the the spark seems to be good. I did the module mod, but still have the same problems. The diagnostics show a consistent cam position code (03), but I had an Acura that did that even though the cam sensor was good. Are there any good ways to test the cam sensor or am I stuck with replacing the distributor just to see if that fixes it? Thanks for any ideas you guys have!

It is impossible for his cam sensor to be bad and for the car to run.

Really? I thought limp mode kicked in, based on feedback from the other sensor and preset values.

Then again I'm that crazy guy who believes that the death of his ignition module was related to a short circuit surge caused by a coolant leak...

tehbrookzorz wrote:Really? I thought limp mode kicked in, based on feedback from the other sensor and preset values.

I think this is true if the Crank Sensor goes but not if the Cam Sensor goes.

With the crank sensor gone my car just ran rich and hesitated. It wasn't even bad enough to be called limp mode.

I have no idea whether the Cam Sensor failure would be catastrophic, but I could easily believe that. At best I think it would be much worse than the Crank Sensor failure.

I was just making the point that there are varying documentations on this engine, some refering to these sensors individually, and some calling them both cam sensors. I know they are physically different and are treated differently by the ECM. They also cause a lot of confusion.
I was getting codes suggesting both of my sensors were faulty, changed the crank sensor, and continued getting both codes. Odd, that when I changed my disty both codes dissappeared. I however suspect more at play in my case.

At any rate, more thought on the subject was all I was looking for. Thanks Neumann.