I got this car and drove it about 500 miles and it ran great minus a little bit of a rough idle. Recently, I drove it about 3 miles and the car started sputtering and would barely go down the road. Literally 5 miles an hour. I pulled off the road and let it sit for a few minutes. I started it back up and it ran fine to get it home. Later that night, I drove it for about 510 minutes and it started sputtering again. Cut it off for a minute and it started up and it drove fine for a couple minutes and did it again. The last few times, I would drive it around my neighbor and it has gotten worse. Now it is happening in a minute or two after driving and after you cut it off and let it sit, it doesn't go back to normal driving. It has to sit several minutes in order to start up and drive normal for a minute or two. I have changed the plugs and put new fuel filter and neither have helped. Any feedback would be great.

 

Is your car a V12 or 6 cylinder?

 

If you've got a loose or breaking connection to the ignition cutting one side of the V12 out you'll get something like what you've described but you need to give us more details! year model etc any

 

V6

 

I got this car and drove it about 500 miles and it ran great minus a little bit of a rough idle. Recently, I drove it about 3 miles and the car started sputtering and would barely go down the road. Literally 5 miles an hour. I pulled off the road and let it sit for a few minutes. I started it back up and it ran fine to get it home. Later that night, I drove it for about 510 minutes and it started sputtering again. Cut it off for a minute and it started up and it drove fine for a couple minutes and did it again. The last few times, I would drive it around my neighbor and it has gotten worse. Now it is happening in a minute or two after driving and after you cut it off and let it sit, it doesn't go back to normal driving. It has to sit several minutes in order to start up and drive normal for a minute or two. I have changed the plugs and put new fuel filter and neither have helped. Any feedback would be great.

 

Perform a fuel pressure test to see if the pump is functioning correctly.

 

Fuel filter 'clogging-up'?

I had an MGA (back in the 1970s) that would do the same thing.

Filter element clogged with rust/debris and when it sat for a while the debris fell away from the mesh. Car ran fine for a while and starved for fuel again.

 

The engine is not a V6, BTW, it is an AJ16 straight six, the last of the straight six engines produced by Jaguar until the Ingenium 6 came out very recently, I had something very similar with a 1980 XJ6. Fuel filter gauze in the tanks were completely blocked.

 

I've moved your question from General Tech Help to XJS forum and then merged it with the identical question you posted here. Please do NOT multiple post the same question acroos the forums. This is the place to post technical questions about your model.

Graham

 

I put a new fuel filter on it and it didn't resolve the problem.

 

What is the fuel pressure on start-up, at idle and at WOT?

 

I am not sure how to check the fuel pressure because it doesn't have a connect on the fuel rail to hook it up. How can I do it? Is it likely the fuel pump? I tested the injectors and they all seem to work.

 

I didn't pull them off, I put a screwdriver to them and felt the tick on and off

 

Change your fuel filter, hope your pump is not burning out

 

I already changed the filter and it didn't resolve the problem. Any other thoughts?

 

Hi buynap1

It could be the 'Coolant Temperature Sensor' that's causing the problem

If the 'Coolant Temperature Sensor' goes Bad, then the Engine could Start 'Overfueling' which can cause all sorts of problems

Where the Car may be very hard to Start or not even Start at all or may Start and run ok for a while and then Start pulling the Car up

In order to Test this you can Bridge it with a Piece of Wire or Paper Clip, which will fool the ECU into thinking that the Engine has reached optimum working Temperature

Have a look at Page: 95 of my 'Write Up' 'Carmen Won't Go' where I had to try every trick in the book to get my 1995 XJS 4.0L Engine to Start

Lots of Stuff in there that might be useful from Removing and Testing the Coils to Removing the Fuel Tank and Replacing the Fuel Pump together with loads of Photos and on Page: 95 you can see how I bridged the 'Coolant Temperature Sensor'

Which in this case wasn't the problem (Link to that page below)

Carmen Won't Go Trying almost every 'Trick in the Book' to get 'Carmen' my 1995 XJS 4.0L Engine to Start including Changing the Crank Position Sensor

 

It’s more likely the AJ6, the AJ16 came with the 95 and 96 model years.

He should have no coil on plugs.

I would check and clean the throttle body as a quick and cheap attempt.

It could be the TPS, which is costly.

Im afraid I would need more information. It could be the plug wires? That would be something that would need changing if it’s still original. It would need changing if it hasn’t been changed in 5+ years.

 

Definitely no coils on the plugs and it is the AJ16. I drained the gas tank today and then put 2 gallons of clean gas in it and now it won't start. Tries to but won't stay running. Does that help. New plugs, distributor cap and button are clean and look new. I have a set of wires ordered for it and should get them Tuesday. Still thinking it could be the fuel pump but don't want to go there unless I rule out everything else.

 

You said it yourself "distributor cap", that means you have the earlier AJ6 engine. You also said "definitely no coils", so that means it is NOT the AJ16 engine. The AJ16 engine has individual coil packs which you say you definitely do not have. Just so you are clear of which engine you have so we can help troubleshoot.

 

Thank you. I guess I have the AJ6. Sorry, I am new to the jaguar game and I got some conflicting information earlier in the week being told it was the AJ16. Do you have any suggestions on the problem?