My idle has increased from 600 to 750 RPM in drive. Is this an indication of a defective Throttle Position Sensor. These are over $400 on E-Bay. Do any of you know if this sensor causes this. My CPS and Idle Air valve are new. Amazing that the sensor for the 4.0 is so expensive as compared to other TPS on cars. Any advice would be helpful
RagJag

 

Ragjag,

My first thought would be to look for a carbon coating buildup on the throttle body which is keeping the butterfly slightly open thus raising the idle. Try cleaning it gently.

Next thought is an air leak somewhere on the inlet side. Go around with a spray and check every possible joint area whilst the engine is running.

Just to let you know, a new throttle potentiometer (JLM12074) from Jaguar is £141 so not sure why people would ask $400 on ebay.

Good luck

Paul

 

I just bought one from Jaguar classic parts (Heritage) last month, with exchange rate and shipping it came to $155.26




Craig.

 

When the TPS dies the idle goes up to 1200-1500, so this is not the case.
+1 on Paul's post.

 

1. Clean throttle body

2. Perform a manual idle speed reset. (Check forum, I know the steps we're posted, I think I may have posted it!)

3. Take car to dealer to reset adaptations. should cost you $150.

One of those three steps should resolve your problem.

 

Ptjs1, Several on E-Bay were $500-600.
RagJag

 

Ragjag,

I think that probably goes to show that there are people on ebay just trying it on. £141 new from Jaguar, so no excuse for people charging $500.

Good luck with sorting it.

Paul

 

ptjs1, ordered the part from Heritage. Cost about $200 with the higher exchange rate.Still less than half the E-Bay prices. This may not be the problem but the one in there now is 18 years old.
RagJag

 

Vee, there are no dealers in Richmond that work on the XJS. 14 years old is the cutoff.
RagJag

 

You may consider taking a ride up to Springfield, VA. There's a Jag shop with a working PDU!

 

Thanks, Vee. I will consider doing that if I can't solve the problem myself.
I have heard of that shop before.
RagJag