Intermittent starting problem...need input!

Hey guys, I'm looking for a little bit of input into a recent issue I'm having with the YJ. I'm having a very bizarre intermittent starting issue. Basically the story goes like this:

I picked up a part-time delivery gig while I'm looking for something full-time. I work generally three days a week, and on the other four occasionally run errands, but I'm not beating on the car like I do during the delivery gig. I've had the job now for about a month, but it wasn't until about two/two and half weeks ago that my issue started. The problem generally occurs on the days I work when it's under more stress, and didn't start happening until I began using the Jeep more.

Anyway, I go out to the car after it's been sitting for a few hours (say 4+) or overnight. She starts right up just like she's supposed to. Everything checks out fine except my battery gauge which lately has been running higher (around 16V) than its usual 14V. I drive around for a little bit, everything seems fine.

Then out of nowhere, boom, she'll be dead. And when I say dead, I mean completely dead as in no crank, nothing. I turn the ignition and the whole car seems to almost ground out. The electronics go dead until I move the key back to the 'On' position, where everything begins to work normally once again. Lights all work and I hear the fuel pump priming just like it should after turning the ignition to off.

When this first happened I tried all the usual: checked battery terminals, connections, etc. After tightening them up (in front of someone's house rather embarrassingly) she fired back up and I was good to go. Later that night though, she was once again dead in the water in front of some stranger's house. I again checked the connections, and when that didn't work I nearly gave up. Here's where the real magic happens though.

In frustration I slammed the driver door behind me when I got back in the car (takes a lot of effort to get it to close right) and turned the key almost simultaneously and she fired up perfectly. No hesitation, no excessive cranking, nothing. I was, and continue to be, shocked. This is how I have to get her started every time this problem pops up, which all day Friday was every time I went to start her. And before anyone suggests rocking it while it's in gear and then turning the ignition, that only worked once and I've tried that at least 10 times. Because of this I began thinking it is no longer the starter itself.

Luckily (?) for me it had gotten so bad that it wouldn't start yesterday morning even after sitting for close to nine hours when I went to work to find the problem. While I was under the hood, I had my mother (who begrudgingly agreed to help me) turn the ignition so I could listen to see if I could hear anything trying to at least engage. What I heard was a rapid clicking noise, which I am going to assume is a relay somewhere. After some quick thinking, I decided to bang on the fuse box with my mother still turning the ignition, and wouldn't you know it she fired right up.

As a result, I went out and purchased a new starter fuse. Once it was replaced, it started perfectly for the next three hours, where I drove around to check to see if the problem would re-occur. I probably started the Jeep close 10 times, and every time it was perfect. I thought my problem was solved, because had I started the Jeep 10 times any other day somewhere in there it would have been dead.

So I go to work, and on my first delivery of the night, the Jeep throws the 'Check Engine' light at me. This had happened three days earlier as well, but upon shutting the Jeep off and turning it back on the light disappeared and never came back on until yesterday afternoon. Same thing happened this time, I shut the Jeep off and the light disappeared. 15 minutes later though the light reappeared, and this time something very noticeable was going on. The Jeep nearly stalled out on me and without my foot on the accelerator was idling around 200 rpm.

So I bring it to my house and switch cars with my old man. He takes a look at it (former mechanic) and tries to start her up and once again she's completely cooked. However he happened to notice that the check engine light was flashing, basically the way he described it was Morse code. Long story short I stayed up until 4 this morning and learned that this flashing is the Jeep throwing codes, and after some research I now speak fluent Shitbox. The Jeep is throwing code 24, which indicates an issue with the Throttle Position Sensor. More research indicates that this does indeed seem to be my issue, as this will cause the CEL to come on while driving and make it idly extremely low, then high, and so forth.

The reason I'm coming to you guys for advice is because honestly I don't know if these two problems are somehow related or if I have two distinct things happening here. In terms of the TPS, it's most likely a 20 year old part and is the correct reason why the Jeep is throwing that code. But the starting issue is now coinciding directly with this. As I said, I've begun to think it's not the starter that's the issue but something in the electrical system along the way. The problem is that I've researched and given plenty of thought to at least 10 different causes for the issue, ranging from a loose connection to a bad relay to the ignition switch and even to an issue with the ECM, which quite frankly is doomsday for the Jeep if that's the culprit.

I'm sorry this post is so long guys, and I seriously appreciate any help I can get with this. I don't want to sink unnecessary money and time into fixing things that ultimately won't solve what's going on. And if anyone can provide me with a solid explanation there's definitely a beer in it for you the next time the club gets together for a cook out or what not.

Thanks guy and happy wheeling.

T.J.

THOOPY3 wrote:and after some research I now speak fluent Shitbox

This may be my new favorite quotation of all time, ha ha.

The TPS, as I understand it, wouldn't give a no-start condition. It more causes bucking and jerking, surging idle, sudden stalling, and generally bad running of the vehicle.

I'd more likely guess a Crank Position Sensor failure. That would create an intermittent start condition. Try disconnecting it for one minute and plugging it back it. If that fixes the no-start, then it indicates the sensor is bad.

Sounds like a bad connection!
How old is the battery?
Voltage issues can cause erroneous codes.=
A false code that means nothing caused by something that had low voltage or a bad ground etc.
Sounds like a bad connection somewhere .
Is battery a maintenance free type or type with removable caps? if removable caps check to see if it is full.
I have had battery's with a empty cell cause things like that.
I have also had batt cables go bad with corrosion inside cable under insulation, gets batt acid inside and corrodes it.

Hmmm, CPS wouldn't kill all the electricals.

Maybe a loose wire in the ignition somewhere?

A bad crank pos sensor will not stop it from cranking over. But It will stop it from running. I believe that the issue he is having is that the starter does not work at times.
The rapid click coming from the starter sounds like a bad connection or junk battery.

Both of you have suggested things that I was also thinking. I ended up changing the starter relay over the weekend and other than one little blip I haven't experience the issue. Of course that blip also directly coincided with the check engine light coming on immediately upon start up when I did get it running so I'm not sure if it was related to that.

I changed the TPS on Monday; check engine light is out and she's now running like a champ. As it turns out I also have a busted power steering pressure switch which should be coming UPS hopefully by the end of the day today which should account for my slightly low idle RPMs and occasionally difficult sharp turning.

I'm also mulling over what sounds like a high-pitch whine from under the hood when I turn the key to the on position. I've pin-pointed it to something in the fuel pump electrical because when I pulled the fuel pump relay and turned the key to on the noise disappeared. I thought that might be my no-start issue, so I started the Jeep with it out and it cranked, started, and then immediately died (as it should have) so that's not the problem either. I should add into this that the fuel pump is brand new as of four months ago and quite frankly I've had nothing but problems since it's been installed, been back to the shop at least three times to correct the shoddy work they did. But hey, their loss not mine, all the repairs were free so they should have gotten it right the first time.

Before the new pump was installed, I was accustomed to hearing the low-pitch humming of the fuel pump. This one also does that, but as I've said I can now hear a high-pitch noise which I did not hear before. Do you guys think this might have anything to do with the no-start?

Was the fuel filter changed when new pump was installed?

x2

While you can change them at a separate time (YJs have an inline filter instead of the one in the tank like TJs), you want to eliminate anything that may have caused extra stress on it.

Fuel filters are best changed every couple of years, anyhow. (Even though many people never change them out, but if you drop the tank it often disturbs any debris in the bottom that can clog up the filter.)

To be honest I'm not sure if it was. I'm currently on extremely bad terms with the shop I had the work done at because the last time I was there they snapped one of my fog lights off my bumper and covered their asses by pulling the "We're not liable if it's parked outside" crap so they heard it from me.

I haven't had any other starting problems since the time of my first post though, which means sometime tonight the Jeep will catch fire and burn to the ground. On a very different note my speedometer and odometer decided not to work this morning. I have since fixed this problem, but wouldn't you know it was because of faulty wiring done at the above-mentioned shop. For future reference, don't use Pioneer Garage in Peabody.

Good to know. Man, that's a lot of incompetence for one shop.

When I started going to them about two years ago, they were great. I had no problems, their rate was excellent, and the Jeep was running strong. But I had them do my fuel pump in late July followed by a very necessary tranny swap/slave and master overhaul in early August and I've had nothing but trouble.

A month after the tranny swap their brand new slave cylinder went (which was initially the reason I did the tranny swap). Then I unexpectedly ran out of gas about 60 miles short of my usual trip distance. Upon making it to a gas station, I filled my tank to full to find I could only get 13 gallons max (over-filling) as opposed to the 15+ I could get before the work. Called them out on it, so they fixed the slight float in the gas gauge, but all they would say is that the tank looked like it was compressed when they took it down so of course no fault on their part.

Less than two weeks later, my fuel gauge started pegging to full randomly and because of my extremely warranted trust issues with these guys, I assumed it was something they did. This was nearly the same time I started having issues with the Jeep starting, so I figured the two were related, the more annoying of the two being the starting problem. My thinking with the fuel gauge was that the ground they set up was bad, and I hit it right on the nose. But to my surprise they also acknowledged that the actual wire powering the fuel pump was also no good so they replaced both of them.

It was during this trip to the shop that my fog light was snapped off and cracked down the middle. And because they're such low-lifes (in my opinion), they actually glued the housing back together to try and hide what happened, and to their credit it worked...until I pulled into my driveway and saw that my light was noticeably sideways. Called them, no answer; left a message, no return call. Called them the next day, talked to the guy who did the work, he said he'd talk to his father and brother (family shop) and see if they knew anything and that they'd get back to me. Of course no return call after this either. They started avoiding both my calls and my father's (Jeep is registered in his name) until the two of us used *68 or whatever it is to make our numbers private.

And as it would turn out today with the speedometer, the wiring for the speed sensor in the t-case was Mickey-Moused together and water/ice/something unknown must have gotten into the brilliant electrical tape work they did to hide they fact that they cut the speedometer wiring harness (from what I can tell) for no reason. Now, I did have them install a 94 transmission into my 92, and the speed sensors are supposedly different...but my transfer case was re-used and thus there would be no need to change it. It looks as if they chopped the harness plug/end off of the 94 t-case and spliced it into my old harness and went from there. The wires aren't even the same colors, that's how I know it's a hack-job by them.

Sorry I'm always writing such long messages on here. My journalism background shows haha. Plus this is good therapy.

Damn...yeah.

Even when I have great shops do work...I'm never satisfied.

Every time someone else works on my rig, I regret it. If for no other reason than I realize I could have done it myself and known what was actually going on.

Yep, I hear you on that one. The worst part is that they specialize in Jeeps. Now I'm not the most mechanically-inclined person on the planet, certainly not the worst, but after the amount of stuff I've personally done on it lately I'd say I could give those guys at Pioneer a run for their money if I opened a shop right next door.