Hey guys! It has been a while but I have a couple quick questions.

First, just so you remember I have a 94 XJ12/40.

My first question is, is it normal for the car to idle really high when you first start it (especially in winter)? Mine climbs up to the 1700-1900 range and sits there for a good 3-4 minutes before it starts coming down. When the car is warm it idles at about 750-800.

Also yesterday for the first time my temp gauge just slightly climbed above the Normal mark which it has never done before, not even in the hot weather but it is cold out now so???? Is this a warning sign of something bad to come?

Oh, I almost forgot. Is there suppose to be a rubber seal around the gas tank flap??? I ask this because on mine there is none or no idication there ever was one, and when it rains out a little lake of water fills the whole area around the filler neck. It is so bad that if I twisted the cap off water would go into the gas tank so I have to blot it all up with a towel before I can put gas in...not fun.

thanks folks

peace out,
daddylogan

 

The cold idle seems high. Perhaps a coolant temp sensor.

There is a drain tube for the fuel filler. Blow it out with compressed air. That should solve the pooling problem.

 

I was told that V12 engines were prone to making higher tepms .Glad, XJ40 and X300 V12 engines more reliable over 5.3 V12 . I think you might be also running on slightly low coolant and when your engine is cold ,check out your coolant level . If necessary top it up and see if it makes any difference .

 

My 6 pot XJ40 4.0 is also prone to this sometimes in cold weather. My solution is to switch it off and start again. This has worked fine for the last 6 years.

When you do blown the drain out you might want to check behind the trim that you haven't blown the pipe off. Next time it rains your trunk/boot will fill with water.

 

Wrong temp sensor. Sounds like you are thinking of the one for the gauge. Besides the gauge sending unit, the Marrelli ignition cars had two other temp sensor. One works for the engine ECU and one for the Marrelli ignition box. (the second one is no longer available new.)

 

Thanks for your reply which is very informative .I can't help but ask why on earth did they use some notorious Italian brand instead of Bosch ?
I call it notorious because almost all Italian cars have had electrical glitches over years .

 

Magneti Marelli took over Lucas some years ago.

David

 

David ,Thank you for shedding light on my question

 

I think it had more to do with drinking wine and pinching girls on the butt.

 

Hey guys! Thank you so much for the reply's to help point me in the right direction.

Once again my vehicle is a 1994 XJ12/40

Anyhow I now can give a detailed account of what is going on but naturally I don't know the solution yet. I just think this is more good and accurate info that might help someone here get that light bulb turned on nice and bright!!! LOL

First, back to the temp gauge. It now seems like every other day or basically "random" that the temp climbs above the "N" mark. Now ever since I have owned the car it always warms up to the "N (normal op temp) and it stays there. But, when I first made this post it was going to the first slash mark past the "N." Never went higher than that and would kinda bouce between "N" and the first slash. I was starting to think big trouble coming on with the cooling system but the car ran good, and was retaining all it's coolant fluid(s).

Well, then the next time I go drive around, it goes up to the "N" and stays there like it should...never past. TODAY however it did strange things. First thing in the am after it warmed up, I went to get gas about 1 mile away and all was fine. Then after I got the gas and pulled out to the highway enterance I noticed the gauge starting to rise again up to the first slash marker. Well, my destination was about 55 miles away so I was concerned but figured let's see what she will do. Well it made it there while bouncing between "N" and the first slash again. But I did notice something else...I was going about 70-80mph and when ever I let off the gas pedal it would seem like the car would "jerk" like it was struggling for gas or like it was trying to die. It would only do this for the split second I lift off the gas pedal and then it would be back to ok again.

Ok so I make it to my destination. Then I decide to go visit a store I never get to since it is out of town. Well I got stuck in traffic for a bit and then is when the gauge kinda went crazy...it went the highest I have ever seen it go which is just pass the SECOND slash mark after "N!" This was approaching the red zone and now I was really worried, but as soon as I started moving again it went back down to just above the NORMAL slash again??? Ok, so I spend some time in the store and then get ready to go home and here is when more new syptoms began. I started my car and it started doing this up and down thing on the idle. It would go from almost barely idiling (100-150rpm) up to around 700rpm and then back down again, alternating and then it died. I restarted it again and it did the exact same thing again...now I was freaking out figuring something bad had gone wrong and I would be stuck towing and paying a Jag dealer to fix. Well, the third time I start the car I give it some gas and it finally goes back to normal idle and I decide to chance getting home so I take off. Now here is the funny part of the story...it ran perfect the whole way home and the temp gauge stayed at "N" the whole way!!! So, I made it home and parked her.

This leads me to post here before I decide what to do. I want to hear what you guys think or are there things I can do to try and repair what is going wrong.

As for a little history on my car to help out:

1) Since I have owned the car I have ran two tanks through with fuel injector cleaner

2) I use nothing but Premium gas

3) All fluid levels are fine

4) Had an oil change to synth a couple months or so ago.

Sorry for the long post, but I wanted to include every detail so it might tip some of you experts off to what it may be or what is going to happen! LOL

Thanks for reading and I hope to get this resolved :-)

peace out,
daddylogan