My 1988 Jaguar XJS has been misbehaving lately, not all the time but just on occasion.
My car spits and sputters and behaves like I was giving it gas then letting off the pedal and then doing it again. Then when it spits like this I kinda stomp it gently and give it more gas to get it going then it is good for awhile. Then it did it again yesterday, it ran good for several hours then it started to sputter again, so I ran it til it stopped cuz I had to get home then it didn't do it today.
What could cause this? Tomorrow I am going to change the fuel pump. And see if that works. I also put some gas treatment in the tank because I thought that maybe condensation caused the problem because of the heavy dew we were getting here with the weather change.
What a fuel pressure regulator?
Got any more ideas?

 

From your description it does sound like a fuel issue.

1)Have you checked the fuel filter? If it's plugged then it's an almost sure bet that the screen in the fuel sump tank is also plugged. The sump tank is the small tank the that fuel flows into from the main tank. The fuel pump draws from the sump tank.

2)Yes, a pressure regulator can cause this. In fact I had the inlet (right side) regulator fail on my '88 XJS...which gave severe but intermittant surging and bucking similar to what you've described.

3)The TPS--throttle position sensor--can cause similar problems. This is the device that sends a signal to the ECU in direct response to the throttle pedal and plays a prime role in fuel metering.

Item #1 is a visual check but #2 and #3 require testing....and testing is valid only if done *while the problem is occuring* so it might be a little difficult to confirm if they are faulty under the circumstances.

Post back for more details if you want.

Others will chime in with more ideas.

Cheers
DD

 

Hi Doug, I had to have my car towed today. I took some videos and it looks like a blown head gasket to me, there is white "smoke" coming out the tail pipe.......but everybody knows it really isn't "smoke" but coolant burning off.....I am not happy about this situation.
If you send me an email at jetlag700@hotmail.com I will send you a couple of videos I took today while I was waiting for a tow truck.
There is only 128,500 kms on the car and I thought it would last longer than this.
Hey Doug, you know my buddy Art Dickenson, him and I talk all the time on the phone, what a crazy Englishman,, quite funny too. ha ha.......
On a side note, can you believe that a new member complained about my picture of the "suit and tie", the one that is seen as my avatar?
I told him basically to take a hike, I was really purturbed that he had the nerve to go through my pictures then complain about it, he acted like I had a naked picture of myself or something. Some people..........

 

deleted copy of message above, bumped the buttom twice

 

I sent an email.

Blown head gaskets are a bit rare on the V12 but it does happen. Make sure the shop verifies the diagnosis before taking things apart. Replacing ahead gasket is a helluva job on a V12.

Art is a great guy. He introduced me to slaloming...although my skill in that sport never quite matched up to my enthusiasm :-). I haven't seen too much of him the last 2-3 years as I don't get up to Canada like I used to. Sometimes life just gets in the way, as the saying goes.

Cheers
DD

 

Hi Doug, I sent you an email with a video but I got it back with a message that said "Postmaster Failure", so you didn't get it. Do you have different email address that I can send the video to?
My car is at the shop, I had to have it towed yesterday.....I need a great big sand pile to stick my head in. As you said it rare that the V12 needs a head gasket, and I am hoping my car doesn't need one. I talked to a guy in the southern United States who sells engines and he said there is only SIX V12's in the whole North American continent for sale. Doesn't look good.
How come it is rare for a V12 to need a head gasket? I would think it would be common with the heat in the engine bay, and that the V12's heat would eat them like an addict does chocolate!~!~! ha ha ~!~!! Donna
ps. I had to fire up my old faithful-my '87 XJ6, that old thing just goes and goes, and it never refused to start even in the coldest weather. I had it stored last winter and it was not plugged in and it started even when it was 30 below celcius. It had a head gasket go a month or so after I bought it and it was expensive to fix.......seems like these cats think I am made of $$$$$$ or something. But what the heck, if ya wanna drive in style what better way than to drive a Jag even if they have their hissy fits sometimes.
You can call Art, he has my phone number if you want to talk to me, I don't want to post it here because of trolls and perv who might be skulking around on our forum.
I think this forum is great, we all help each other in our experience of ownership of Jags.
I wish they did not stop making the XJS. But I suppose they would be a $150,000 new eh? <<<<<< my XJS