An issue that has been ongoing for months! Initial problem started with the rover not wanting to stay running, chugged.

Changed pre cat O2 sensors, no change. New issue, high idle!

We could not control the idle to stay @ 700, would increase to 2k and we couldn't get down. At times the car wouldn't even idle, or fire. The continuing code we got was P1172.

Items we changed:
MAF
IAC
air filter
Crank position sensor
new spark plugs (4x's)!
muffler
Checked for vacuum leaks, the only area we found was the o ring was missing where the MAF connects to the air filter.

We new we were getting fuel, just too much. Couldn't figure out why we were running so rich.

Thanks to Disco Mike, he gave us info to follow. He steered us away from the MAF because he indicated the MAF was not the reason for running rich.

After much time and money, we found a donor vehicle at the local junk yard. We replaced the IAC, fuel temp sensor, coolant temp sensor. After installing the rover still ran rich (which caused the rover hard starts). After cleaning and or replacing new plugs, we could get the rover to start, but then idled high, again!

The original ECU did not appear to want to relearn the new parts. From previous posts, it might appear we ran the car too long at high idle and caused the ECU to go into limp mode. Went back to the junk yard for the ECU and TPS.

Installed the ECU and TPS from donor vehicle, along with the other parts from the donor vehicle (IAC, fuel temp sensor, coolant temp sensor). Car purrs like a kitten now!

Not sure if we even needed those parts, but for the $30 paid for TPS and ECU, I'm betting this was all we needed! Given the original ECU did not appear to want to learn the new parts added, we eliminated the issue by using the donor ECU. Should have just done this in the first place, might have saved us $$$$!

Thanks to all of the posts read that helped steer us in the right direction, hope this helps some of you, as this was very frustrating! Just glad to have my rover back on the road! And much owed THANK YOU to Disco Mike who was patient with us and very informative!!!

Happy Trails!!
Jeff & Vera

 

Great. I had this same problem (high idle, won't re-learn new or cleaned IACV). Same fix, fly low and fast with the parts vultures.

 

By the same fix, you mean a replacement ECU from a donor car? Or ECU and TPS?

 

ECU and IACV.

 

I have a 02 Disco 2 with 110,000 miles that is running rich and while stopped for traffic lights it will begin to idle really rough and produce a strong smell from the exhaust. I have changed MAFS, plugs, wires, air filter, and fuel filter. Only codes that has showed is P0327 and P0308. No coolant loss but have noticed that while idling a small puddle will form at the tailpipe. Please help I going crazy and broke.

 

Just a minute - how would you change just the fuel fiilter? It is built into the fuel pump. If they charged you for that, hmmmm....