Hi All,

I have been working the basics on this problem before posting. I bought a 1996 XJS 2+2 a few months ago. It has been well kept and runs well basically. I noticed immediately that it hesitates from a stop, it's a slight hesitation then continues on as usual.
I am fairly adept electrically and mechanically. I have replaced the fuel filter, the spark plugs, fuel pressure regulator. I have cleaned the MAF, the throttle body, ECU connectors (they were fine).
I know the basics of an engine are: Fuel, air, and exhaust. The curious thing is that when it is first started, it has no hesitation for the first few blocks. I am starting to lean toward the catalytic converters as the possible problem. I also saw a post by "Brutal" about setting the TPS to .6V at the sensor, I will try that next as it doesn't cost anything.
If anyone has an idea what might be causing this, please let me know.

Thanks and Happy Motoring!

Zac

 

Try cleaning the EGR Valve.

It's easy to get to. Shouldn't take long.

I replaced mine, but upon removal I realized that I could have saved myself $100 and cleaned up the one that was in the engine bay.

If it isn't that, I don't know what else to tell you.

 

My apologies...I neglected to say that I had also cleaned the EGR valve. It was actually easy. Oh, and there are no codes being thrown out by the OBC (on board computer).

 

Something electrical is malfunctioning as it heats up. The ignition coils will usually cause a misfire, but I HAVE HAD this type of hesitation due to a bad coil. I suspect you have a bad coil or a bad TPS. The TPS needs to be reset by the Jaguar computer that some old dealers and independents have.

Good luck

 

Thanks for the info Spikepaga. I will call the local dealer and check wheter they have the appropriate equipment to do the TPS reset. Will also source some new coils. Is there a way to tell which coil is causing the problem, or do I need to cycle the coil and test drive until it goes away?

 

You might want to raise your hood, turn of the garage lights and see if one of them lights up with your car running. Sometimes you can see the misfire thru the top of the coils. If you do need a coil make sure you buy an OEM replacement with the "made in Japan" label on it. Aftermarket coils fail very quickly