2012 Jeep Wrangler JKU starting issues

[twodogs112]

Ok, I have been helped before on here so I’ll try again. My 12 wrangler has a very strange problem. First some background is in order. Purchased used, have done so far engine wiring harness from mopar, plugs, injectors, catalytic converters, o2 sensors, shocks, rear main seal, torque converter seal, all new sensors, just about everything is replaced. The jeep runs great everything works as is should.

Now the issue, first start up of the day is perfect. No lights, warnings. Drive around a bit. Turn off. Come back to start. Everything comes on , does not crank at all. No noise , nothing, except the electronic throttle light comes on and stays on. No flashing. Does not come on while driving. I can get it started if I disconnect the battery cables and touch them for about 2 minutes. At first this was all I had to do. Now I have to do it several times. Then it starts right up with no issues.

So, I replaced the battery with a new one, no indication of corrosion on the terminals or connectors. Did that yesterday. Today same thing happened. No start, aft we r about an hour of sitting, started right up.

I have JScan, and another reader, no codes, before, during, or after. I have a new throttle body I can install. But I don’t truly believe that’s the problem. Does anyone have any ideas? Anything would be appreciated. Thanks.

 

[Snowbird Tom]

Change the battery terminals for solid metal ones. The OEM bent steel ones from Chrysler are junk and lose contact easily.

 

[BLACKJKU]

Does the little red dot in the upper right side of the dash cluster come on when this happens?

 

[twodogs112]

Already done!! My next idea is to add an additional ground wire tomorrow. I have come up with all kinds of solutions. Transmission neutral safety switch. Transmission overheating, it’s not those , done the testing. I’m stumped!!! Oh, I also had the clock spring replaced by the dealer. So it’s not the key. Odd thing is no codes of any kind. At any time!!!!

 

[twodogs112]

Not the keys, have two new and factory original key. No difference.

 

[BLACKJKU]

Not the keys, have two new and factory original key. No difference.

But what about the battery in the key FOB?

 

[twodogs112]

No lights except the lighting bolt electronic throttle. Stays on, no flashing.

 

[twodogs112]

Checked, they are good!

 

[BLACKJKU]

Have you tried starting it in neutral when it does this?

 

[twodogs112]

Yes, same as on park.

 

[BLACKJKU]

Sometime when it happens you should try checking the key start wire on the starter to see if it's getting power when someone tries to start it.

 

[twodogs112]

I thought about the starter, but it starts right up after clearing the computer, or after sitting for awhile. Drove around the block for about 30 minutes today monitoring the transmission and coolant temp. Both different numbers. Trans temp about 211 at the highest. My coolant temp runs at 200 to 211 . While driving longer distances. I don’t suspect anything mechanical. It’s got to be electronic.

 

[BLACKJKU]

But most things electronic will give you a CEL, so need to check things that wouldn't give a CEL. Like grounds, bad battery cables, clamps, run another ground to the engine from battery.

 

[twodogs112]

Good point. I’ll do an additional ground wire tomorrow.

 

[BLACKJKU]

One more thing I just thought about is pulling the IOD Fuse when it happens.

 

[twodogs112]

What is the iod fuse. Location? I also had a strange thought. This is a toad for our rv. We have an onboard battery charger that tops off the battery while towing. I just went out and removed the fuse to it so it is not on. Could that be it?

 

[twodogs112]

Thanks for your help, you gave me the idea for the o2 foolers awhile ago when I was having issues with the cats and o2 sensors. They worked!!! So thanks. Appreciate the help.

 

[BLACKJKU]

IOD is in the fuse box in the TIPM, Google the IOD it kinda sounds like your issue.

No idea on the charger, but wouldn't think so.

Glad to hear I had a good idea for a repair for you. But it helped to figure the problem since I had it also with the o2's.

 

[BLACKJKU]

Any luck yet?

 

[twodogs112]

Sorry the delay. The wife retired from work yesterday and she had me busy!!!

Update, replaced the battery, no change. So I decided to remove the air intake pipe. Cleaned the throttle body, wiggled the connection to the throttle body, cleaned outside, seemed a little loose, clicked it back in. Inspected all the grounds from the battery I could see. All looked good, checked starter ground as suggested, good. Put everything back together.

Just for curiosity sake. I had some 8 awg wire left over from a project on the rv. So I made an additional ground wire that attaches from the battery to the body ground next to the fuse box.

Also looked at the j13 fuse, looked ok, but I could not figure out how to get it out. Left that alone.

Results, started right away. Drove for about 20 minutes. Turned off. Then started back up. No issues, no lights on the dash. Ok!!! Waited awhile, took it on about a 45 min drive, same results.
So , don’t know for sure if it was a loose connection to the throttle body or the ground. I’ll be disconnecting the ground wire today and see if that’s it. I’ll post the results later. Thanks for the help. You guys are the best!!!