Jeep Wrangler TJ won't start? Read this!

Alex01

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Hi All. I'm a member of the WrangerlForum, just found the TJ.

I have a new to me 2003. 4.0, automatic. 1 owner prior to myself. In Feb I began having start issues. Per auto zone's advice, replaced the alternator. Worked for a few days. Problem returned, took it to a mechanic that I've never used (out of town). He advised the the PCM was going bad. That was a headache. Bought one on ebay and had wrangerlfixllc repair/program. No issues, has been running like a champ. Two weeks ago, had a slow crank but start, and then no crank. Replaced the battery at that time. Started and drove fine for the weekend. Sat for a week, went to fire it up last night. Nothing. No click from starter. It did ding once or twice, and the gas/break/seatbelt/check gages lights flashed then nothing. (it is not low on gas and break is not on). The random lights are a bit of a concern. That was one of the first issues that pointed to pcm going out.

I have a volt meter coming via amazon tomorrow, going to start with checking the batter is charged. At this point its easier then me pulling it and taking it back to the shop I purchased it. Also going to try to jump it. Little confused that the new battery would be dead after only a week, so goes the relationship I have with the jeep thus far. Feels like a stray dog I'm trying to domesticate and every time I get close I get bit. It is my second jeep, and selling my first was the worst mistake I've ever made. I'm learning a lot from this one.

I haven't noticed the mentioned issues that would point to ignition switch pin. I can pull the key out while driving and it stays running. (thought I was going to die the first time they fell out.)

The connectors to the battery are clean and free of corrosion.

I do know there is a multifunction switch in the steering column that needs to be replaced. At this point the only symptom of that is the hazard lights occasionally coming on when I turn off my turn signal.

Thanks for any/all input.

Also, if anyone is in North West Louisiana/Arkansas, let me know, could use a few Jeep friends!
Sounds to me like you have a draw on the system that is draining the battery when it sits.

Maybe try throwing a battery tender on it to charge the battery then unplug it before you let it sit next time??

I assume it fires right up when jumped...
 
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Chris

Chris

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2004 Jeep Wrangler, inline 6, 166K miles and daily driver. Several years ago, I had the battery cables replaced because of corrosion issues. The shop that did the work was sloppy and left the old cables cut, disconnected and dangling. I thought it was sloppy work but did not complain because I thought it was just cosmetic. I thought because these were disconnected on both ends that there would be no risk of shorting something out.

Fast-forward about 2 years. Been having intermittent starting problems. Cold start seems to be getting a little rough to turn over (relative to normal). I decide to just keep an eye on it. From a warm start, after a quick trip to the store for example, the start is even rougher. I’m starting to get worried that I might end up getting stranded somewhere. But the next morning on a cold start, all seems well. I had noticed this for a week or 2 and was just monitoring the situation. Battery is less than one year old at this point.

I try to do the easy things – replace air filter. Makes no difference. One morning, it won’t crank at all and all the gauges are bouncing when I try to start. I’m late already so I take another vehicle. As a precaution, I order a new starter, ignition switch and clutch safety switch just in case.

That evening, I decide to try the old bang-on-the-starter-with-a-hammer to diagnose the starter. It doesn’t work. I get to poking around inside the hood just looking for something amiss. I note the old, cut positive cable just dangling so I attach it to the engine block ground and try again. It turns right over but will not stay running unless the accelerator is depressed. I poke around some more and find the old negative cable just dangling. So, I attach it to the engine block together with the positive and try again. The engine starts and it runs good as new! While it is running, I remove both loose cables and it stays running. I drive around the neighborhood and park.

Next day, it starts up just fine and so I drive it to work. I go out to lunch and it starts fine. When I leave at the end of the day, it starts fine. I make one stop on the way home and again it starts fine every time. I make it home and park. Later, I need to run an errand and it won’t start. It is the same problem as before, it won’t crank at all. I reconnect the black cable. Same thing happens. It turns right over but won’t stay running. I reconnect the red cable. Once again, all is well. I disconnect the cables and it stays running.

What the heck is going on?

Hi All. I'm a member of the WrangerlForum, just found the TJ.

I have a new to me 2003. 4.0, automatic. 1 owner prior to myself. In Feb I began having start issues. Per auto zone's advice, replaced the alternator. Worked for a few days. Problem returned, took it to a mechanic that I've never used (out of town). He advised the the PCM was going bad. That was a headache. Bought one on ebay and had wrangerlfixllc repair/program. No issues, has been running like a champ. Two weeks ago, had a slow crank but start, and then no crank. Replaced the battery at that time. Started and drove fine for the weekend. Sat for a week, went to fire it up last night. Nothing. No click from starter. It did ding once or twice, and the gas/break/seatbelt/check gages lights flashed then nothing. (it is not low on gas and break is not on). The random lights are a bit of a concern. That was one of the first issues that pointed to pcm going out.

I have a volt meter coming via amazon tomorrow, going to start with checking the batter is charged. At this point its easier then me pulling it and taking it back to the shop I purchased it. Also going to try to jump it. Little confused that the new battery would be dead after only a week, so goes the relationship I have with the jeep thus far. Feels like a stray dog I'm trying to domesticate and every time I get close I get bit. It is my second jeep, and selling my first was the worst mistake I've ever made. I'm learning a lot from this one.

I haven't noticed the mentioned issues that would point to ignition switch pin. I can pull the key out while driving and it stays running. (thought I was going to die the first time they fell out.)

The connectors to the battery are clean and free of corrosion.

I do know there is a multifunction switch in the steering column that needs to be replaced. At this point the only symptom of that is the hazard lights occasionally coming on when I turn off my turn signal.

Thanks for any/all input.

Also, if anyone is in North West Louisiana/Arkansas, let me know, could use a few Jeep friends!

Both of you will get much better responses if you post this as a new thread.

When you piggyback off old threads like this, they get typically less than half the attention and responses that they would if you'd just posted a new thread.
 

Roccrawler3

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I was gonna tell you that the starter for the 91 - 95 YJ 4.0L Is the same starter used in the TJ 4.0l funny thing is it's a Hell of alot cheaper to buy the YJ model starter than the TJ one. Got a YJ starter in mine it works just like it should. Just an FYI for the future.
 

Jayramble

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Looking for wisdom - Have a 99 auto that recently has a CEL code P0123 (TPS) but that has been changed and occasionally backfires - believe it to be a faulty Crank Position Sensor (long story).

But now it wont start on an intermittent basis with just a click (radio, etc. works) yet with the engine off and transmission in Low (1st) i pushed it thinking I may rock the starter but it rolled forward a metre/yard and wow it started would this movement on an auto have dislodged a stuck starter? Or is it another issue?
 

MYERSCT99

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UTAH
I have seen many posts on this board with people incorrectly diagnosing starting issues, or giving advice that requires a lot more wrench turning and guess work than necessary. I figured I could make a little diagnostic write up to better inform people about how to test the system, and how it works in our Jeeps.

One thing to keep in mind is that the starters ONLY job is to turn the engine over. If your starter is cranking over the engine but it's not firing, your problem lies elsewhere.

The first step in properly diagnosing the starting issue you are having is to verify your voltage. If you are not getting enough power to the starter, you cannot properly start your jeep. Grab a voltmeter (NOT a test light, those are useless here), and a twelve pack. I prefer Guinness or New Castle, as they have a high Jive-osity ratio when working on my jeep, but anything will suffice. You may need a friend to give you a hand turning the key while you take some voltage readings.

1. First, we start with the battery. This is where you get your power from. If you have a load tester, hook it up to the battery posts (there is no need to remove any cables). Make sure your battery has a decent charge. 12V - 12.6V is acceptable here.

2. With your voltmeter on the batter posts, turn the key to the start position, and read what the voltage drops down to at the battery posts. If it drops below 10.5V or so, you either have a bad connection at the posts, low battery, or a bad battery. Make sure the posts are free of corrosion, charge it up, throw a new one in, do whatever. If you have the battery tested at a shop, keep in mind that you cannot correctly test a batterywithout it being fully charged. Once you have your freshly charged/new battery, throw that sucker in and if you still don't start, proceed to the next step.

3. Have you cracked one open yet? If not, do so.

4. Once you have verified that your batteryis able to produce enough current, you need to check your feeds to the starter. We will start with the ground, since that is more common of a failure from what I have seen. With your volt meter, put the positive lead on the positive battery post, and the negative lead on a clean metal surface on the starter body, or the solenoid mounted on it. Any clean metal surface on the starter will suffice. Verify that the voltage reading you get at rest is the same as the battery reading at rest. Have your friend (you gave him a beer too, I hope) turn the key, and note the the lowest point the voltage drops to. Remember the reading we got when trying to crank at the battery? You do not want to see more than a 0.5 volt decrease at the starter when cranking. If you drop more than that, you have resistance in your ground circuit. Trace it back until you find the point where the voltage is being lost. That includes the cable, the connection at the batteryend and the end that mounts to the motor, the connection where the starter mounts, everything in between. If you are having trouble tracing it back, just start at the starter and move the volt meter back one connection at a time until you get a good voltage reading. That will tell you exactly where you are losing your ground. Once everything checks good, we need to check the live feed to the starter.

5. Put the negative lead on the negative post of the battery, and the positive lead on the large post of the solenoid on the starter, where the live batter cable runs to. Perform the same tests as we did on the ground cable to check the live feed. Everything good? Let's check the ignition feed now.

6. Keeping the negative lead where it is, put the positive lead on the small wire connected to the starter. This is the ignition terminal, when you turn the key to the start position it sends power to this terminal to engage the starter. Take the same readings as we did on the cables. Note that this wire should ONLY be live with the key in the start position. If you have low/no voltage here, then you are not getting power through the ignition, and should check for a bad/broken wire, ignition switch, etc. In a Manual jeep, check to make sure the Neutral Safety Switch and related wiring is in working order.

7. If you have sufficient voltage present at the starter and still not cranking properly, then your issue is most likely the starter (or a seized engine). More than likely you can replace the starter and be on your merry way.


COMMON STARTING ISSUES:

RAPID CLICKING: 99% of the time it is low voltage to the starter. Check battery and feeds as detailed above. Basically you have enough current to engage the first coil in the starter solenoid, which pulls the plunger in and engages the drive into your flywheel, but not enough to power the holding coil which keeps it in while cranking. This causes the solenoidto release, and the re-activate since the current in the system is brought back up. this will happen rapidly, hence the click-click-click-clicking. VERY rarely it is an imbalanced solenoid on the starter. The voltage readings above will diagnose it properly.

NO CLICKING AT THE STARTER: Check for a loss of ground to the starter, or a loss of voltage at the battery. Check the ignition terminal on the solenoid for power when trying to start. If none of those circuits have any issues, the starter is bad.

JUST A CLICK: Again, verify the voltages. The solenoid could have enough power to engage and feed current to the starter, but a loss of current in the ground/cable/battery could be causing the starter to not crank properly. If the voltages are fine, change the starter.

STARTER SPINS, BUT DOESN'T CRANK THE ENGINE: The drive in your starter is blown or the gear is chewed. Change the starter (or drive if you are so inclined). Also check the teeth on the flywheel, make sure they aren't torn up. It is also possible (but unlikely under normal circumstances) that your drive shaft is snapped, or the planetary track in the starter is worn, in which case a new starter is in order.

STATER STAYS ENGAGED AFTER ENGINE STARTS: If the starter stops spinning when the key is off and the engine stops turning, check the ignition feed to the starter, make sure the ignition switch isn't faulty and supplying voltage to the starter when not in the start position. The drive could also be binding mechanically. If the engine stops turning and your starter is still spinning even with the key off, you have a low voltage issue. Basically what is happening is you have enough voltage to crank, but it is low enough that the contact diskin the solenoid is welding itself to the contacts due to heat from loss of amperage. Find your voltage drop in the battery/cables. I also suggest changing the starter/starter solenoid, as this causes the contacts to become distorted and chewed, and will cause problems in the starter.

CRANKS SLOW: Again, check voltages, change starter if necessary. Notice a pattern?

A NOTE ABOUT HAVING AUTOZONE TEST YOUR STARTER.

Autozone, C.A.P. and the likes cannot PROPERLY test your starter. I say this because every store I have seen test them just puts power to it to see if it spins and to check that the drive pops out. There are many problems that cannot be determined through that alone. Worn or gummed up brushes, a slipping drive, and worn contacts in the solenoid are just a few of the issues that can make a starter turn over on the bench, but not in your jeep. If have yours tested and they tell you it is fine, take it with a grain of salt.

Feel free to keep this thread alive by adding your input, suggestions and any more information I may have missed.

Up until 2 months ago my TJ started and drove just fine. I did have a leak so i decided to replace the rear main seal, oil pan gasket, and valve cover gasket. Once I finished that project I went to go start it with no luck.

What's been tested or replaced up to this point:
- Verified all connections
- Tested and I have spark
- I have fuel pressure at the fuel rail schrader valve. 42PSI
- Battery seems good. It tested 12.3V and was manufactured on 8/2021. Terminals are clean and connections are good
- Replaced the CPS
- Replaced ignition switch

Could I have messed up the fuel injectors when I cleaned the exhaust manifold when it was off?

Any help would be great

Chris
 

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I was gonna tell you that the starter for the 91 - 95 YJ 4.0L Is the same starter used in the TJ 4.0l funny thing is it's a Hell of alot cheaper to buy the YJ model starter than the TJ one. Got a YJ starter in mine it works just like it should. Just an FYI for the future.

What year is your TJ?