Jeep Wrangler TJ 2001 -cranks but won't start
This has gone on for months. The Jeep just died one day and
starts when it wants to. Usually cranks but won't start. Changing computer didn't help. Gas
gauge doesn't work but will work if the vehicle starts.
Can you help?
How about checking the timing on the Jeep and have it done properly. Your spark plug wires may be off by one or two and that could be the problem right there. If it's not the timing, then it could be your fuel system. You may be getting the spark and the air required, but no fuel. Also, check the air delivery system, i.e.: your air filter, all its corresponding hoses to the air intake manifold, etc. When your TJ cranks, does it bog? Meaning does it seem to struggle during cranking? What are the temperatures like when you start your Jeep? Temps have a lot to do with the time to start because your oil is a lot thicker and will not allow your internals to cranks as quickly as they need to. Write back! Sean Dickerson email@example.com
Thanks for the help Sean3090 but this one is not so easy. My Jeep has been to a few mechanics that cant find the problem. Cranking is fine and not labored at all. The problem started in the summer so temp makes no differance. It seems that when it doesn't want to start that there is no spark and the engine doesn't flood, it's like some parts of the electrical system are effected. Like I stated even the fuel gauge acts up when it wont start. I am thinking maybe its the crank sensor but would it be controlling so many things.
I'm have this exact problem same symptoms also the volt gage doesn't move for about 10 seconds until the check engine light comes on then it reads about 9 volts. I suspect it could be a ground issue but haven't found it yet. Was going to try and ecm until I saw this.
My jeep wrangler finally quit starting, just cranked no start, same symptoms so I could diag it now. What I eventually traced it to was the switched 12v feed wire for the ECM runs in the harness from the underhood fuse block past the battery to the ECM. It had a small pinhole in it and was corroding from the inside, which is why I was only getting 9 volts it was hard to see but the wire had begun to swell a bit from the corrosion inside. I replaced the bad section of wire by soldering in a new piece. Problem solved.
This is a common problem and it is just a bad crankshaft position sensor. This crank sensor is cheap and easy to replace. When they go bad, the Jeep will start sometimes, and other times it will crank but not start. It can even die while you are driving. The part is about 30 bucks. Just put a new one on and set the spacing properly.
A bad crankshaft position sensor will not allow spark or fuel....but the Jeep will crank away....just will not start, whenever the crank sensor acts up. Replace it and it will run fine.
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