I'm having an odd no start issue. I can't repeat it, the Jag either cranks and starts or it does nothing. The engine does not turn and the starter is not clicking. I can hear a faint noise of some type but dot really enough to determine what it is. I seem to have full power as all the lights, stereo, and AC blower motors work. But nothing happening under the hood.

I've been working my way through the XJLover's Engine Will Not Crank FAQ

This is what I've done so far.
Battery tested good with Multimeter and @ local shop
New Alternator tested good with volt meter and @ local shop after install
Battery terminals are clean and tight
Pulled and cleaned battery ground strap
Pulled and cleaned engine ground strap
Installed a redundant ground strap to top of engine

The driver's side voltage distribution point on the firewall looked good when I pulled the wire for the alt install, but I did not clean it.

The passenger side is not as clean, but doesn't look bad.

Tested the starter by supplying 12v to the red/white wire and it turned, however the Jag was able to be started with the key at that time.

After cleaning the ground it started 8 or so times in a row. 2 hours later it would not start with the same symptoms.

I might try and get the connectors on the starter tonight. Is there any easy to get to them that I'm not seeing?

Another interesting thing to note was that the guy at the local shop said my starter sounded slow when he was checking my alt. When he tested it he had an odd look on his face and had to go inside to ask the other guy about the test. Basically neither of them had any idea what the test revealed, but suggested a new starter. At that time I had no issue and was reluctant to replace a "good" part.

I guess I'll need to catch it in a non start state to test the relay further.

It started fine today at lunch. Any thoughts?

 

Could be the starter solenoid on top of the starter motor. You need to ttry another unit. These motors eventually start to get troublesome as I found out with a 1980 Series 3 I had. (14 years ownership and sold in 2002)

 

You've covered most of the bases. As you know you'll really need to catch it in-the-act to confirm if it's the starter itself or something ahead of the starter.

Might wanna clean/tighten the connections at the starter relay and/or open up the relay and clean the contacts.

Cheers
DD

 

I guess that's why I've read to tap the relay if it's not working. I may actually have a spare relay. I picked up a grab bag of XJ6 electronics a while back. I just need to look through it. Any specifics to cleaning the relay? Open it up and spray it down with contact cleaner?

Is there any way to test the solenoid? No garage and rain tonight means no testing till later.

 

Just pry out the little locking tabs/crimps to remove the tin casing off the relay base and clean the contact points with emery cloth or similar.

I don't know of a on-car test for the solenoid specifically but you can remove the white/red wire from the starter relay and apply 12v to it. The starter should operate. If it doesn't it could be the solenoid or the starter motor itself....or a bad connection right at the starter.

Cheers
DD

 

I tried that at lunch today. 12v to the red/white wire turns the starter every time. But then again it was starting at the time.

 

Yeah, that invalidates the test. Gotta be ready to jump out and do it the next time it *won't* start !

Cheers
DD

 

I found a spare in the grab bag. It's pretty grubby on the outside, but that's not really what counts. I could always swap the clean cover if needed.

Just checked and she's starting. Amazing how it starts for me in the driveway, but quits on the wife 70 miles away.

 

Hopefully the wife views that as an adventure rather than a problem :-)

IF the problem occurs after a long run I'd lean more towards the starter, as starters will often act up if they've absorbed a lot of engine heat but work fine when cool.

(You didn't mention that the problem occurs when hot but I took a leap and inferred it from the "...70 miles away" remark)

Cheers
DD

 

I'm not sure how hot it was when they had the issue. They drove up the night before and were running around shopping withing a 5 mile area from where they were staying. Stopped for dinner and it didn't start when they were leaving. So the Jag had probably been sitting for at least an hour.

The next day I drove it home and it sat long enough to cool off before I began working on the ground strap. I started it several times after everything was back together and then it wouldn't start for me about 2 hours later.

My gut feel is that while heat may make the no start worse, I have experienced the no start while the Jag was not up to operating temp essentially a cold start.

Update : Swapped for the Jag at lunch yesterday and she did beautifully. I was even out for a couple of trips last night and I had no starting issues.

 

After 2 days of driving around town with multiple starts per day it finally quit again. This time I was able to jumper the red / white wire to the battery and the starter turned. So that should mean the starter is good.

Working down the list of connections on the starter relay.
Brown wire has constant power

I had the brown wire off to get access to the white / yellow wire and the engine turned over...maybe got too close to the red/white and made a connection? By the time I was able to test the yellow / white wire it was starting again. Maybe not a good enough connection on the yellow white wire. At that time the yellow/whiteSince the engine was warm and I had little time to play around with it I sprayed the connector and tab down with contact cleaner and everything seems to be normal.

A dirty connection might have been the whole issue. I guess I'll have to drive it some more to see.

Thanks again for all the help!

 

Back from vacation and driving the Jag around. I haven't had the no start issue since I cleaned the connections to the starter relay. I didn't take the relay apart yet. I just cleaned the connectors to the relay.

However this morning the starter gave me a terrible noise and didn't crank. This was about the third start of the morning and after turning the key back to the off position and back on it started right up.

So sounds like a new starter is in order. Has anyone had any luck with The Driven Man's NipponDenso starters?

http://www.thedrivenman.com/Jaguar/Starters.htm

 

Not from DrivenMan but I've used these new gear reduction starters on two of my Jags. Worked great but in both cases I had to fabricate/jury rig shims/spacers to get the right mesh on the ring gear.

I could be wrong but I think all the Jag vendors are selling the same g/r starters.

Cheers
DD

 

I spoke with "The DrivenMan" and he said their starters are machined to fit, so there should be no shim needed. I placed my order today so I'll update the thread after I get it installed.