I have a 1996 XJS with the AJ16 engine.

So my car stalled at a light. It threw out P0727, P1775 and P1315. The transmission trouble light also came on.

I cleared the codes and the car actually drove great!

I may be sucking some air at the IACV due to one stripped thread, which I intend to get to this weekend.

The question is, do these codes shed any more light onto a rough idle condition? I believe it may be a vacuum leak, but are these codes an indicator of anything else?

Thanks.

 

What spark plugs do you have installed? The PO installed some iridium plugs in my AJ16 just before I purchased the car. Drove it home from Batten Rouge to Atlanta and it gave me poor gas mileage and posted misfire codes. Several weeks later before I had a chance to look at the plugs it went into limp home mode and gave transmission fault codes. I took it to the dealer to have a pre-purchase (after the fact) inspection. The service manager and I did the inspection on a Saturday, Compression was 175psi on all cylinders and that is when we found the incorrect plugs. I Replaced the excessively expensive plugs with the $2.00 plugs listed in the owner's manual and cleared the problems. Have not had a fault code or poor idle since.

 

I've always stuck with the Recommended Champions RC12YC.

I pulled them all off, regapped them and put them back in. No difference.

Retapped the IACV holes and tightened the screws up. No difference.

I'm taking it to the Jag shop with the PDU. They'll figure it out.