1999 TJ Starting Problems

[jcarr99TJ]

I am having starting issues with my 1999 Sport 4.0 Manual transmission. I have installed a "refurbed" PCM from an internet company and I can only get a single click when I turn the ignition. i had to replace my original PCM due to no spark condition which was the result of a bad main chip which would not send fire command... I can pop-start the jeep with no issues, which is more than I could have originally done prior to PCM swap.

I'm really perplexed after having replaced the ignition switch, starter, battery, crank position sensor and distributor pick-up sensor. I was Speaking with @Wranglerfix and he suggested I ask the brain-trust here. Any tips, hints and pointers aver very much welcomed and appreciated....

thanks

john

 

[P man]

Stop replacing parts...do you have spark? Do you have fuel pressure? If so was the fuel pressure in spec?

 

[JSpike]

You obviously have fuel and spark if it runs when you push start it !!! I would go to starter, wiring, clutch pedal position switch ,then ignition switch.
Turn key on and jump starter, if it starts go to clutch pedal position switch, bypass this and see if it starts. Lastly I would go to ignition switch and make sure everything is adjust correctly. Good luck

 

[jcarr99TJ]

Stop replacing parts...do you have spark? Do you have fuel pressure? If so was the fuel pressure in spec?

Yeah, I have fuel and spark.

 

[jcarr99TJ]

You obviously have fuel and spark if it runs when you push start it !!! I would go to starter, wiring, clutch pedal position switch ,then ignition switch.
Turn key on and jump starter, if it starts go to clutch pedal position switch, bypass this and see if it starts. Lastly I would go to ignition switch and make sure everything is adjust correctly. Good luck

The starter and ignition switch are brand new, never used. the clutch pedal position is currently bypassed. crossing a screwdriver across the two starter poles does NOT start the jeep. Sending power directly to the starter side pole will spin up the starter

 

[JSpike]

So with the ignition switch in on position and you jump starter correctly apply 12v power to starter solenoid and what happens ?

 

[P man]

You obviously have fuel and spark if it runs when you push start it !!! I would go to starter, wiring, clutch pedal position switch ,then ignition switch.
Turn key on and jump starter, if it starts go to clutch pedal position switch, bypass this and see if it starts. Lastly I would go to ignition switch and make sure everything is adjust correctly. Good luck

Ia that what "pop starting" means? I've never heard that term before

 

[jcarr99TJ]

So with the ignition switch in on position and you jump starter correctly apply 12v power to starter solenoid and what happens ?

With the ignition switch in the on position, and when I apply 12v directly to the solenoid using a jumper wire from the battery to the solenoid the jeep starts

 

[JSpike]

Ok so obviously there's a wiring problem or ignition switch problem, go to bypassed switch and make sure you have good contact between 2 wires. Then I'd go to ignition switch, I know you just put it in there buttttttt it could be out of adjustment, not going far enough.

 

[Jerry Bransford]

Ok, have someone quietly turn the ignition system to Start with you listening for a click at the starter relay inside the PDC. Have your finger on the relay too since you can usually feel it click too. Does it click when the key is in the Start position?

If it does not click, your clutch pedal position switch might be bad. It is what prevents the starter from engaging without the clutch pedal being held down with your foot.

Have you installed the bypass for that as described in your Owner's Manual? It's what allows the starter to be engaged without the clutch pedal being held down. It's done either by moving an electrical connector above the driver's side footwell like shown below. Or it's done by installing a fuse in either the #4 or #10 position behind the glove box, I forget which. How the clutch position switch is bypassed changed from moving the cable connector to inserting a fuse but I don't recall when that change happened.

 

[jcarr99TJ]

Ok, have someone quietly turn the ignition system to Start with you listening for a click at the starter relay inside the PDC. Have your finger on the relay too since you can usually feel it click too. Does it click when the key is in the Start position?

If it does not click, your clutch pedal position switch might be bad. It is what prevents the starter from engaging without the clutch pedal being held down with your foot.

Have you installed the bypass for that as described in your Owner's Manual? It's what allows the starter to be engaged without the clutch pedal being held down. It's done either by moving an electrical connector above the driver's side footwell like shown below. Or it's done by installing a fuse in either the #4 or #10 position behind the glove box, I forget which. How the clutch position switch is bypassed changed from moving the cable connector to inserting a fuse but I don't recall when that change happened.


View attachment 276112

I can hear and feel the starter relay open in the PDC when i have someone turn the ignition. yes, too, the bypass done is with moving the fuses behind the glove box.

 

[Jerry Bransford]

I can hear and feel the starter relay open in the PDC when i have someone turn the ignition. yes, too, the bypass done is with moving the fuses behind the glove box.

When the key is in the Start position, check for +12v on the brown wire connector that connects between the output of the starter relay and the solenoid on the starter motor. If there's no +12 volts on that wire when the switch is in the Start position, check the 40 amp #2 fuse in the Power Distribution Center.

Also for shits and grins swap the starter relay with any of the other relays inside the PDC that are the same size.

 

[jcarr99TJ]

I have 12.5V going to the brown wire when key is turned to the start postion. i swapped out the relay with a new one and no go. still only get 1 click. i checked the ignition switch in the steering column and all is tight...

 

[jcarr99TJ]

Well… mystery solved… previous owner made a splice in the battery to starter main power line… new connector (interim solution) and Jeep is back on the road