Hello All.

I was working on a 1993 XJ12 yesterday with a friend. He had the car delivered after purchasing on auction. We looked things over (things checked out F the MP), put in a good battery and turned her over. She started right up, idled a little high and settled. Idle remained at about 900-1000 rpms and would go no lower. We allowed the car to run - fairly pleased.

After she came to temp (and longer), friend got in, put her in gear and that's where the problems started. Basically as soon as you drop her into gear the idle begins to fail, car stutters, coughs and wants to stall. It is necessary to use the accelerator to keep her running. Impossible to drive. We haven't done a ton more investigating (we will) but I thought I'd put out feelers here,,, to see what suggestions, hints, suggestions, clues and pointers I might get.

Thanks in advance for any suggestions.

 

A 1993 is an XJ40, new body shape. and a 6ltr, and Marelli, like your XJS.

If its the S3 shape, then a 5.3ltr with Lucas Ignition system.

Different in so many ways.

 

Hi Grant.

I did see Marelli components and similarities in the the engine bay, although electricalz, breathers and other things are laid out differently...

XJ40 you say? I was just on the horn with the friend. He swears it an XJ12.

Either way... Any suggestions?

 

I don't know those cars or engines but a high idle and stutters in gear smells like a vacuum leak. Physical inspection and then waft propane or starting fluid around the intake tract and accessories.

 

Agree, whatever the critter's pedigree, it sure sounds like a vacuum leak, possibly more than one. Old dry rubber hoses, prime suspects.


Or, it is only running on 6!!!!!


Carl

 

I've heard of the "running on 6" idea but dont know the a sure fire way to check for that... Definitely going to get a can of carb cleaner or electronic parts clearer (or somethin) and start spraying around the hoses and intake - stuff...

 

Jason,

Like the XJ6 badging, the XJ12 badging also covers MANY year models of Jaguar.

Sooooo, he is correct, it may well be badged an XJ12, just like my wifes 1976 S2 V12 Sedan.

The XJ40 has a single wiper blade, the S3 has 2 just like your XJS. That is SIMPLISTIC for a newby to identify the difference. There are thousands of differences, as the XJ40 is a whole new car.

The 6ltr has different idle control bits.

The S3 5.3ltr engine would have a Lucas Ignition Amp (Black Box) bolted to the LH Inlet manifold.

The 5.3 in the Sedans NEVER got the Marelli, that was the XJS surprise. The 6ltr in any body shape has the Marelli.



Series 3 shape, 2 wiper blades.



XJ40 shape, ONE wiper blade.