You guys have helped me out with issues in the past. This question has partly been asked before. My 2000 TJ 4.0 Automatic is having starting issues at times. The jeep starts great every time except when this happens. You turn the key and either get nothing or sometimes chatter in the starter and then it engages. One the instances that you get nothing all you have to do is put your foot on the accelerator and then the starter engages. I would say it is completely electrical. Itís not like the jeep tries to start but needs fuel. It does nothing until you press the gas pedal and then it jumps to life without hesitation. I replaced the throttle position sensor and thought that fixed the problem. It did seem like it helped as the issue hasnít been happening as often and didnít for a few days after I replaced the sensor. I have also replaced the battery terminals and inspected all wiring. Any idea guys?
Try wiggling the gear selector instead of pushing the gas pedal when it does this? Makes me think some switch or wire is so borderline that the pedal pressure is enough to make something move just enough to make contact. A lot of wires run under the dash that could be tensioned slightly when you press the pedal.
I'm just wild guessing here since I've never heard of this issue. Hopefully someone who is familiar with this specific TJ issue will chime in.
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The lady has been using it as her every day vehicle as her truck's ac has been out. Everytime it happens i will have her try other things in the cab. Gear shifter/steering wheel, brakes. We'll see what happens.
ok. last night i messed with it and got it to not start once. I wiggled the gear shifter around (automatic trans) while in park. As I pushed it forward and backward the starter would click. If I held it forward it would actually start. So where does that leave me? i pushed the brake and this did nothing. so it seems the transmission and gas pedal affect the starting problem.
I would be up for agreeing with you on the relationship with the gas pedal and starter. However, there is no doubt, when you push the gas pedal the starter instantaneously jumps to life…every time. I looked up under the dash and nothing is rubbing on the gas pedal. Does the automatic have a neutral bypass like the manuals? If so I can try that to see if it solves the problem.
For whatever reason, it seems likely that it "thinks" it is in gear. That leaves the neutral/park switch or it's bracket position, or wiring to the switch as the likely source. Maybe see if you can locate the switch itself and work backwards. Inspect it. Is it tight? Is whatever thing from the shift lever hitting it correctly or is it broken? Is/are there a/an wiring connector(s) to it? How about upstream from it on the wiring loom? Maybe under the hood, the throttle cable is moving the wiring loom just a little, or even a fuse box connection?
In God we trust.
All others bring data.
I did some more searching and came across someone else with a similar problem. Looks like there is a switch between the jeep tub and the tranny. Hard to get to but I will try to locate it tonight and see what I can find. One mentioned that its location it can get real dirty and nasty which could cause it to malfunction at times. I will check out everything around the throttle cable also.
Thanks for your input guys...i'll let you know what happens after tonight.
I ran across a car years ago that would do all kinds of stupid things when it was idling yet worked perfect as soon as I pressed the accelerator pedal.
It turned out the ground connection from the battery to chassis had failed and the ground connection was being made through the throttle cable. When idling, no connection through the cable but as soon as you put tension on it ie: stepping on the gas, a connection would be made.
I got underneath it last night and looked all over and traced everything. To my surprise there is a throttle cable that goes from the intake right to the gear shifter on the transmission. The neutral saftey switch on the trans is affected both by the shifter and the gas pedal. Hopefully this is going to be my ticket. I picked up a new sensor today for $20 and will replace it tonight. Figured thats cheap enough to just try it out. While im under there i will check power to the sensor and make sure it is working the way its suppose to. Will update later just incase someone else comes along with a similar problem.
The NSS is not affected by the gas pedal, the other cable that runs between the transmission and shifter is what controls the NSS. That cable connected between the throttle body and transmission you found is really more about controlling the pressure levels inside the transmission and throwing the transmission into passing (2nd) gear when you step down on the gas pedal hard enough. That cable is also known as the 'kickdown' cable since it kicks the transmission into the lower ratio passing gear.
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Hmmm...well with that being said. I replaced the NSS and it seemed to have fixed my problem. It has only been about 3 days now but the problem has not shown back up. Before it was getting to be a daily occurance. As for why the gas pedal and the shifter affected it ability to start is beyond me after what you mentioned Jerry.
Replacing the $20 NSS switch was easy. Easy only after going back to the store for a "thinner" thin walled deep socket. Then removing the front driveline from the front axle to be able to move it out of the way.