Fan goes on when i switch turn key to on position. And my jag doesnt start very well when its warm. At winter it started well but now if car stayed in sunlight it doesnt start as fast as usual. it has to be tried few times. Spark plugs are new. I read fault codes are there was one but i forget what was it, i will post it later
Fault code is P1621
Car: Jag XJ6 -96 3.2litre

 

I have the same symptoms and I'm wondering if the fans are always on or not and what that may signify. I have been reading the "Gentlemen: (No)Start Your Engines!!!" thread and have tried many of the tests. One I haven't performed is the battery voltage while turning the engine over. I'm alone so I can't put a meter on the battery terminals and use the key. I can't seem to figure out where to put my multi-meter so I can see it while sitting in the drivers seat. The cig lighter socket is not showing me any voltage.

For the record:
CEL light stays on after the rest go out in a few seconds.
Battery light stays on as well.
RPM's showing while cranking.
Visible spark.
Lots of fuel pressure.
Nothing broken, cam rotates.
Switched relays around behind passenger head light (back to original)
Shot starting fluid in the air intake and held the throttle down. No start or even a couple rev's. This one fact has me a bit perplexed
Continuous cranking for 10 seconds followed by another 10 seconds and maybe a couple of cylinders are firing.

Further suggestions? Like is there a value I should be reading off the pins in the harness at the cam position sensor?

More: I read about the blue tooth code reader. Don't have one and it would be days before one got here. I do have a generic code reader but I don't think it recognizes a Jaguar.

Most of what has been said here about battery voltage may very well be my problem. Again, anyway to see this while sitting?

TIA, I don't come around here much but I love the forum and love the cars.

 

The fans are supposed to come on immediately. There was a recall way back when. The code may be more related to your reader than the car.
Starting problems with a warm engine could be due to a weak fuel pump trying to overcome vapor lock.

On a Jag- just rig some wires to connect the battery to the meter while you try to start. Your thought about the cam position sensor may be a good one, but I can offer no advice there.

 

I hope I didn't mislead anyone, the car is stone cold. Well, cold for SoCal, about 70º. Any info on the fan recall? My car has been serviced by first the dealer and then a very good Jaguar only 2nd generation shop. I just didn't pay any attention to the fans until I saw the OP's post.

Yeah, I though about running wires from the trunk to the seat, but there must be a better way. I mean that's kinda bush league, eh?

 

Well, in accordance with a couple of suggestions on the Gentleman thread, I cranked the engine over for long enough for it to stumble, stumble and catch. What ever takes place took place. I was able to take it in to see if any codes thrown will shed light on the trouble.

BTW, didn't get cranking volts but it runs at normal idle at 14.25 v. I had cranked it so much I was fearful that I might have pulled the battery down so I put a charger on it. I first tried the start mode of 70 A and it didn't catch. I let it sit for 30-40 minutes at 12 amps and it said it was taking 9 amps. Then I tired my 30 second thing and it ran. I don't know if I trust the charger though. I have used it to power a descaling bath leaving it on low for 24 hours at a time.

It's a Harbor Freight thing from 20 years ago.

I'll report back for the archives.

 

Milt,
Pop either heel board cover off and you'll find a pos and neg lead direct from the battery that you should be able to meter whilst sitting astride the driver's seat for your cranking voltage.


But it does sound like perhaps a failed cam position sensor...

 

Hi,

maybe check my thread:

https://www.jaguarforums.com/forum/x...-issue-168390/

I suggest to check at first step fuel pump relay in the trunk