Help 93 MTX start then stall.

[mutkokhan]

I have a 93 MTX which was running great up until 2 weeks ago. After letting the car warm up it stalled after about a 1/4 mile of driving and wouldn't restart. I came back the next morning and it started right back up. Again I let it warm up and it got about 3 miles and stalled again and wouldn't restart. I've replaced the cam sensor and scanned the codes and all I got was the following, 114, 116 and 542. the car after stalling takes almost 24 hrs before it restarts. When cranking the Tach jumps to about 400 rpms and it runs great until it stalls, (sounds like the computer shuts the engine down.). It never ran rough. Any thoughts or tips would be appreciated. Thanks in advance. Solved. Tested Crank sensor with a pulse tester and it was bad.

 

[sperold]

Could be a water pump leak affecting the crank position sensor.

 

[mutkokhan]

But if the crank sensor is bad wouldn't the Tach not work?

 

[rubydist]

first, the cam sensor drives the tach, not the crank sensor.

second, the symptoms you describe are typical of a crank sensor failing.

third, just because you just replaced the cam sensor does not mean its good.

I would first disconnect the cam sensor and see if the symptoms disappear. if so, change the cam sensor again. if not, replace the crank sensor.

fourth, I have never seen a SHO run right with a 114 (air charge temp) code. you need to dig into that and determine why the act is not reading properly to ensure the car runs right.

 

[mutkokhan]

Wouldn't the 114 code (Intake air temp out of range) be because the car has not warmed up yet? the code 116 also has to do with the engine not being warm, yes? Already disconnected the cam sensor still no start after stall.

 

[rubydist]

114 says the intake air temp is not between -40F and 212F. I have never seen a SHO run properly with that code.

if disconnecting the cam sensor does not impact the non-start issue, then you need to change the crank sensor.

 

[mutkokhan]

Disconnected the cam sensor and the tach still works.

 

[rubydist]

then you have a very serious problem, because the cam sensor drives the tach. if the cam sensor is disconnected, there is no signal to the tach.

if the tach works with no cam sensor, then you have a little gremlin in there moving the tach.