So my 06 XKR finally arrived yesterday.
It drives fine until you give it some. Then it pulls well until around 3000RPM and then feels as though the rev limiter is kicking in. If I keep my foot on the gas, it eventually gets power again up to around 4200RPM when it again loses power. Keep my foot on the gas and it gets power again and pulls nicely to redline.

The gas tank was almost empty when I got the car so I have filled it up with premium gas.

Any ideas?

 

A quick and easy thing to check is the throttle cable, but this almost sounds like a vacuum leak (?):

 

^^ First things first - do the quick-and-easy throttle cable adjustment shown above, then drive the car and let us know if performance improves....

 

Do yourself a favor and spend a few dollars on an ELM327 OBDII adapter from eBay and the TorquePro app for Android (or iPhone equivalent). This will give you a wealth of information, including your fuel pressure (clogged filter, etc), fuel trims (vacuum leaks, air flow meter), air flow, water temp, etc., in addition to any standard OBDII codes.

Best of luck, keep us posted.

 

Thank you. I've ordered one and it should be here tomorrow. Do you happen to know which iPhone app works best?

 

I use DashCmd and OBDLink but it depends on what scanner you bought.

 

I got this one:

 

The throttle adjustment worked a treat!
What an awesome forum.

Thanks everyone

 

Glad it worked. Does that solve the hesitation issue completely?

As for the OBD2 scanner, I believe you can use DashCmd with that one (I have a different wifi one so I can't be 100% sure).

 

It appears to have cured it but I only took it a couple of miles in my lunch break. Time will tell.

Thanks again.

 

You could also take your car to Auozone and they will print out a report after OBD analysis. Our store here in Phoenix does it free.

 

Update.......................
I took another look at the throttle linkage adjustment when I got home last night. Gave the car a quick test this morning and WOW! It ran so well and accelerated so hard that the local law enforcement had to pull me over and comment. (Warning).