My 2000 Jeep TJ 4.0 was working fine on Thursday when parked then Sunday went to start and was acting like battery was dead. I pop started it and it fired right up. I let it run for 30 minutes then shut off and have same problem. I pulled the battery and had it load tested and its fine. When I try to start it, it slowly cranks and won't start unless I pump the gas then it won't stay alive unless I give it gas. The check engine light is on for the post cat O2 sensor could this be my problem? Any ideas?
Thanks

a bad 02 sensor won't cause the engine to turn over slow. that would be battery trouble. do you have a muti-meter to test the battery yourself? see if it has at least 12 Volts with engine off. you can also test the battery with engine running (around +_14 volts)to see if the alternator is working.


you say you had the battery tested but i question the results:shaking:

Yeah tested my self and got 12.031 while off and 14.065 while running cleaned terminals and have no clue really. It acts almost as if there is no amps thats why I had it load tested

and you checked/cleaned the battery terminals/cables right?

i can't think of too many reasons the engine won't turn over and over as long as you have the key on and a good battery- even if you are getting no fuel and it never starts. it should keep turning over till you run the battery dead.

Yeah thats why I'm dumb founded cause usually I can leave it for a month and it'll fire up right away. Could the starter or siliniod be going bad causing them to draw to much power

Yeah thats why I'm dumb founded cause usually I can leave it for a month and it'll fire up right away. Could the starter or siliniod be going bad causing them to draw to much power


don't think so but i did have maybe a similar prob with my 95 Dodge truck, V10. hit the key and if it didn't start right up then when i hit the key a second time the engine wouldn't turn over- acted like dead battery. i ended up trying two other batteries, same deal.

had a mechanic look at it and he said the starter was drawing too many amps so i bought a new starter, same problem.

i ended up bypassing the starter from ignition to a manual switch, took care of that.

anyway.........i would be curious what would happen if you tried starting your TJ by jumping the starter with a screwdriver if you know what i mean?

Jumping with a screw driver?

Like This

http://www.moparaction.com/tech/archive/roadside/03B.jpg

Jumping with a screw driver?


yeah with the key in the on/run position (in park/neutral of course) you should be able to reach down from under the hood (in a standing position) and "jump" the starter with a screwdriver(i like to use a phillips) as shown in the picture.

Well just tried to "jump with a screw driver" but it just made a whine and didnt try to fire the engine at all. What does this mean? Starter bad? Silinoid?

Well just tried to "jump with a screw driver" but it just made a whine and didnt try to fire the engine at all. What does this mean? Starter bad? Silinoid?

Meter it the voltage at the starter, See If your getting 12 volts, This should let you know if the wire is ok to it. If It checks ok

Then I would say it is a bad starter

Edit: Starter and Solenoid are sold as one piece.

Well just tried to "jump with a screw driver" but it just made a whine and didnt try to fire the engine at all. What does this mean? Starter bad? Silinoid?

the solenoid is supposed to kick-out the starter gear and engage with flywheel. sounds like this did not happen. did you try and jump the starter more than just once? sometimes you will get some sparks and scare you off from trying some more:flipoff2:

Yeah tried several times but same thing

take the starter off, bench test it (make sure you are using a proven battery) and see if the solenoid is kicking out the starter gear. maybe it is sticking and a little grease will help (slim but a chance). if you can't get the starter to work on the bench then you may need a new starter.

take the starter off, bench test it (make sure you are using a proven battery) and see if the solenoid is kicking out the starter gear. maybe it is sticking and a little grease will help (slim but a chance). if you can't get the starter to work on the bench then you may need a new starter.

Good Advice

hope its not the starter, cheapest i could find was $165 for a reman,, i got lucky, it was the battery.

Its the starter :( new one goes on after school tomorrow guess I will drive the '88 VW cabrio to school tomorrow I already feel the laughs