I had a previous post about a couple of issues with the new to me XK. Getting code P0852 and cruise not working.

Had a new battery installed today but both issues remain.

More troubling, I had a chance to finally open it up (just bought it last week). it completely cut out at 4500 RPM 's or so. Like sputtering and coughing so to speak. Tried again same result. Any ideas what would cause this? Car runs ands sounds great below 4K.

thanks for the responses

 

without codes, shooting from the hip. Clogged Cats?

P0852: gear shifter adjustment?

 

No codes at all except for the 0852 neutral safety switch voltage. First time at full throttle it kicked down a gear and then like huge misfire. Punched from a dead stop and above 4500 it cut out like that again. No codes or CEL.

 

Sounds like the rev limiter kicking in, but that should only happen in P and N. Weird.

 

That sounds a lot more like insufficient fuel supply. Start simple by changing the fuel filter. Read your fuel pressure and verify it is within limits.

 

Also check fuel pressure BEFORE replacing filter. That way you have a reference and can see if it made a difference.

 

Checking at idle is fine , but I'd be more interested with how the fuel pressure reacts
​ when he's under WOT.

 

It's definitely seems to be some type of limiter or management system. It's at 4500 on the nose when it cuts out. Tested with the paddles in multiple gears. Pulls like train up to that and sounds perfect.

if it was related to the pump and fuel pressure, wouldn't it be erratic when it misses or cuts out? It's like something is telling it to cut fuel at 4500. Strange. It's going to the dealer on Tuesday.