Banging my Head Against the Wall! ****

[mygrayzj]

Bad bad news, will explain later. Hoping I don't have to kiss the Jeep goodbye :'(

[Goonies.nsd]

Bad bad news, will explain later. Hoping I don't have to kiss the Jeep goodbye :'(

Uh Oohh.

[mygrayzj]

Soooo here is the synopsis, and I have a bad pit in my stomach thinking about all that could be or go wrong.

Well we ripped into it a bit today, not good. Found that (or think we found) that it is a ground problem with the starter relay. My pops jumped the relay with the key on and started right up, good a ground issue can't be TOO bad. WRONG!!!!! We traced it back through to the firewall, finding 0 resistance all the way to a connector (12 pins or so) attached to the firewall. On the 1st part of the connector the resistance stayed at 0, 2nd side it jumped up. Now I know jack about wiring and electric, but this can only be a bad thing ( I think ). So we kind of played with that and decided that maybe the relay is grounded through the NSS, so I tried to start the truck in Park, no good (no cranking, no nothing). Shift to neutral, cranks right up but will not fire until I give it gas. Then until I shift it out of neutral it would not idle unless I was on the gas, it would flat out die like there is no fuel pressure. As of right now, it is starting in park but needs to be given gas, it is starting in neutral same conditions, and i do not know about the bucking problem. And the reason I posted maybe no more Jeep is because when we got it going before and revved it we heard a nasty knock and the same sound as the Orvis has with a bad bearing. So more is to come, any possible help is so greatly appreciated. And btw I made it to Riverhead today, had to take the father's car.. I am so scared for the Jeep, and my wallet.

[mygrayzj]

Looking around, can't find anything for the dying right on start up, but it looks like the TPS could be causing the jumping. Sorry if someone already said that, but is this one OK or should I go with a more expensive one (Airtex or ACDelco)?

[Goonies.nsd]

Well im not a huge fan of cheapo electrical parts only because they like to fail in oddly different ways down the road than what made you change them to begin with. So when your diagnosing the thing and its acting different your Banging your head and saying "it cant be that sensor i just changed" Its acting different. Then after you go crazy you endup changing the cheap chinese sensor anyway LOL.

BUT to your symptoms of not maintaining idle. The ECMs on the ZJs liked to be dicks if they lost voltage from a bad battery or short. The computers need to relearn after words. They need to have the throttle held up around 2500 and VERY gradually brought down over sometimes a 5 minute period for the ECM to reboot. If you get it started with throttle and let off the trucks would die.

I have no idea if thats your issue but give it a shot before you chase your tale.

[mygrayzj]

Yeah we took the fuse box covers and stuff off and at one point disconnected some battery cable, so I think you are right because I have not had that problem since. Did not end up replacing the TPS today because we got a way to check it and it was checking out OK. I was about to say my other codes went away somehow, but just realized maybe they went when we disconnected the battery (because neither me or my father cleared them). Then I drove it around locally taking my normal trips and just cruising around and it acted 100% normal. Now I need to wait for it to act up again and retest the TPS, because I really think it is that. Until then.. I have a half functional short distance ZJ lol. Glad I have my aunts 5 speed TJ for the time being, hopefully another day or two in case I need it. Love driving that thing lmao

[Bandit1]

glad to hear things are going better for your Jeep... and you...

[mygrayzj]

Thank you thank you So far it has been an inexpensive issue, but racked our brains for a few days trying to think of what could be doing it. Maybe it was just a dirty ground, since that was the only thing we did other than separate the o2 sensor wires that we had taped together.. Thanks everyone for your help, hoping the problem does not return lol

[Bandit1]

dont worry, it will return, you can count on that, but lets hope its return is at a more convient time and location.

[mygrayzj]

God I hope so. It started to do it at BK drive thru before, but I was able to get it to go away by driving up a bit and then sitting it in neutral. Ughhhh