Temp sensor, purge valve, leak detection pump

[HoosierJeeper]

Trying to sort out some issues on my Land Rover. It's an 07 LR3 with the 4.4 Jag V8. 151k miles. It's getting codes for the coolant temp sensor, the purge valve sticking open and closed and high voltage in the leak detection pump circuit as well as running rich on both banks. It usually drives fine and the CEL is intermittent, but sometimes after getting gas it bucks really bad. Sometimes it bucks even if it hasn't just been filled, so there may or may not be a correlation.

I'm having trouble connecting the dots. I'm thinking of 3 different scenarios...
1. Coolant temp sensor is causing all the issues.
2. Purge valve sticking is causing the leak detection pump codes and it to run rich, and the leak detection pump is doing its job. Not sure where the coolant temp sensor fits in the mix.
3. Leak detection pump is bad and causing the purge valve to stick, and causing the richness.

I could be way off base. Really would appreciate some help on this one! Many thanks.

 

[Ramblejam]

Disconnect purge valve hose from the intake, and cap off nipple. Go for a drive. Report back.

 

[HoosierJeeper]

Thanks for the tip. Haven't had a chance to do it, but I did a search on it and it looks like I'd need more diagnostic stuff to play with that.

The more and more I research it, it looks like the coolant temp sensor could really be causing all of this. Could it cause all this stuff? A new OEM one is $47 and it's right up top in the engine bay on the tstat housing. Think that would be worth trying first?

 

[meep]

I don't see the t-sensor having anything to do with the others.

I could see the sticking purge valve influencing test pump performance.

If it were me, I'd replace the t-sensor and the purge valve and see if what all clears up.

 

[HoosierJeeper]

That's what I'm leaning towards. It looks like that leak detection pump shouldn't cause any drive ability issues if it's bad, right?