Tach failed while driving

[mclark]

HEY GUYS WHILE DRIVING THE 94 SHO AUTO THIS MORNING, I GET A CEL , SECONDS LATER TACH FAILED TO ZERO FOR ABOUT 10 SECONDS AND IT CAME BACK UP, SHO STARTED TO SPUTTER FOR ABOUT 10 SECONDS WHILE TACH FAIL UP AND DOWN. DURING THE WHOLE PROCESS I WAS GENTLY PUSHING AND LETTING OFF THE GAS HOPING IT WOULDN'T FALL DEAD, WHILE DOING THIS FOR ABOUT 10 SECONDS THE SHO FINALLY LEVELED OFF . GOT THE SHO TURNED AROUND AND MADE IT HOME PULLED CODE #111. HAD CRANK SEN AND WATER PUMP REPLACED 9-28-2018. I ALSO NOTICED THAT ON SEVERAL START UP THE SHO WOULD HAVE WHAT I CALL A LAZY CRANK FOLLOWED BY WHAT SOUNDS LIKE A MINOR BACKFIRE BUT WOULD START AFTER SEVERAL ATTEMPTS . IGNITION MODULE HAS BEEN REPLACED ALSO. THANKS FOR ANY HELP .

 

[rubydist]

sounds very much like a cam sensor failure. I would replace that.

BTW, PLEASE DON'T YELL AT US.

 

[blk\blk90]

I AGREE WITH RUBYDIST. DOES THE CAR START ON THE FIRST TRY EVERY TIME?

 

[sperold]

^^^^ above remarks from 2 posts.

Cam sensor is sick but not dead yet, and expect a whole lot of strange problems that you will think are unrelated... but they are related.

You will eventually find the car has to be tried 2 or 3 times on separate starter attempts before it finally fires up. And that will be because the timing system can no longer be sure to locate cylinder one to start the timing sequence.

 

[Irish Pride]

I'm gonna say that the DIS is on the way out. Was the Ignition Module replaced after this started happening or before? Is the current Ignition Module a Ford unit or aftermarket?

 

[mclark]

I apologize for the late response, sorry about the caps , but in Law Enforcement all reports are typed in caps. It starts on first try on cold start ,but after driving a few miles it takes several attempts to start it , and when it does starts it sputters and falls dead, but eventually starts . DIS is a new BWD module, and it was replaced before this happened. I will try another cam sensor i have in storage. Thanks guys.

 

[blk\blk90]

I apologize for the late response, sorry about the caps , but in Law Enforcement all reports are typed in caps. It starts on first try on cold start ,but after driving a few miles it takes several attempts to start it , and when it does starts it sputters and falls dead, but eventually starts . DIS is a new BWD module, and it was replaced before this happened. I will try another cam sensor i have in storage. Thanks guys.

All good leo, that sounds like a cam sensor to me. They're a ton easier to change out with the intake and timing cover removed.

Side note, I just picked up my 91+ from a leo up in Indianapolis, then drove it back to Amarillo.

 

[BaySHO Performance]

I agree, classic symptoms of the cam sensor failing. Surprised you didn't get a code 214, though.