Have to hold key to start?

[XJ_4LOW]

Hey guys, strange issue:

2000 XJ 4.0/AW4.

Key in, “on” position everything seems great, hear the fuel pump run. Radio/fan work great.

Turn key to “start” and hear a click, does not turn over unless I HOLD the key in start position for about 4 seconds, then it turns over and starts right up. Always starts on the first turn, runs great.

No changes in the last 10k of smooth running miles, but it has a had a new battery, new starter, jeepcables big 7 kit installed (about 10k ago). Battery tests great.

I’m at a loss on why the key would need to be held in start position for a few seconds to get it to turn over.

 

[Anak]

I wonder if a bad capacitor somewhere in the circuity could cause this. I don't even know where such a capacitor would be likely to be. Maybe in the starter solenoid?

 

[spaniq]

Debugging: have you tried driving the starter manually by removing the starter relay in the PDC and jumping pins C6 and C7? If Anak's right about there being a capacitor in the starter, then this should still have the delay, otherwise not.
Likewise, what happens if you swap the starter relay with, say, the fuel pump relay? If the relay is going bad, swapping it out will show that, and you'd even be able to tell by whether or not you can hear the fuel pump running.

The starter motor is wired directly to the battery through PDC fuse 10 and the starter relay (see: FSM page 8W-21-3). There's not a lot to mess up there, so it should hopefully be simple to diagnose. If it's on the control side of the starter relay, then you have to worry about PCM junk and stuff... since the fuel pump etc run, I'm hoping that's not the problem, but the PCM is a mysterious box to me.

 

[Saudade]

Also check and clean your battery cables, both ends (I realize they are pretty new). Make sure your other grounds are solid.

 

[XJ_4LOW]

Update: looks like it’s just a bad starter, frustrating since it’s less than a year old.

 

[Saudade]

Depending on where you got it, it may still be under warranty.