I have a 2005 Jaguar XK8 4.2L engine with less than 75,00 miles.
Recently, the car has developed a stutter and bogs down on acceleration yet does not throw a DTC.
I am thinking this is the result of a faulty / failing throttle position sensor (TPS).
I plan to clean the throttle body, the TPS connector, and install a new sensor.

Any further insight from other owners/mechanics?

Earlier in the year, I replaced the air filter, fuel filter, MAF, and all spark plugs (regular maintenance).
I also replaced the upper O2 sensors based on "bank 2 running lean" DTC which resolved that issue.
I have had no other issues with the car for about three months until this stuttering problem.

 

You can usually check the TPS operation without the engine running using the live data option on a code reader. You might be able to rule that in or out.

Dirty or sticking injectors often do not generate a fault code whereas ignition problems usually do. As well as throttle body cleaning, perhaps worth a tank full of premium fuel plus good quality injector cleaner to see if that makes any difference.

Richard

 

Unfortunately, I don't have a live data code reader. Also, I haven't yet found a mechanic that I can trust and the Jag dealer near me starts at $160 per hour for diagnostics alone.
Since a TPS is easily replaced and low cost, I thought I'd start there.
Fuel injectors are darned expensive (approximately $200 per and there are 8 of them!). The Jag dealer gave me a quote of $2,600 to replace them all. I can do the job myself but still, parts cost is very high. Has anyone used an injector cleaning service they would recommend?

Note: I only use premium gasoline and have twice recently used a good quality injector cleaner. The car had been running great for that past few months until this stuttering issue.

 

You can check the fuel pressure with most OBD2 readers. It should be around 55 psi. It sounds like this is a low-mileage car, and no DTCs, so fuel pump is a possibility.

 

I understand that you can't check the oil pressure through ODB on the X100 but you can on the X150.

Richard

 

Odd. Even my cheapo ELM327 teamed with Torque Lite/Pro will report throttle position.