I went out this morning to start my Cherokee 4.0 automatic 1994. It turns over but won't fire. Full tank, new fuel pump and filter, tune up, almost everything! No prior warnings. I put gas in the intake and it will sputter and run like it's only firing on two cylinders then it will die. I can't throttle it up. The dash code is flashing 17 = the "coolant sensor". ????? Will that cause it not to start????? I'm lost. It ran fine yesterday. Any help and I'll sure be thankful.

 

Replace that coolant temp sensor. It's cheap and can mess with the entire jeep's operation if it isn't functioning properly. Also, check for spark. Your ignition coil could be bad

 

I replaced the coolant temp sensor and the code for it 17 is now gone, but it still acts the same. Before I changed it I was getting code 12 code 17 code 55. Now I just get code 12 and code 55. I know code 55 is "end of code output" But code 12 is Battery disconnected, and it's not and cranks over fine. In the probable cause line the Haynes book says "Battery voltage to PCM disconnected within last 50 key-on cycles" What the heck does that mean?????

 

sounds like the crank position sensor, i would change it my 94 did the same thing a few months ago. if its not getting fire its the first thing to check or replace then coil if it still dont start.and also if your tank is not grounded it will not start either.

 

I replaced the crank position sensor not very long ago. After looking through more stuff in the Haynes manuel it seems there is an endless amount of things that it could be. ENDLESS. I've already changed so much....but it's outside in the snow in the my drive and we're supposed to get 15 more inches today so I'll try to get into it over the weekend.

 

What brand fuel pump did you use? Please dont say an Airtex