V8S Tuning Resistor
V8S Tuning Resistor
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Oldred_V8S

Original Poster:

3,764 posts

267 months

Monday 28th June 2010
quotequote all
Anyone had any experience of failures of the Tuning resistor on a V8S? My car has been running fine, but recently has started to cut out when hot and is then a pig to start until it has cooled slightly. It feels like fuels starvation/vapourisation and all that I read on the web seems to back this up. I purchased an ECU reader from Steve Heath (very prompt service) which tells me that the issue is code 21 tuning resistor is out of spec. Never heard of one before but am now trying to track one down.

Barkychoc

7,848 posts

233 months

Monday 28th June 2010
quotequote all
The tuning resistor is in the wiring loom somewhere - its taped into the loom I think. That error is that it is open circuit - so I assume its broken.

A bit of info here

http://www.v8engines.com/carbs-2.htm#Tune-resistor

The tune resistor selects different maps in the ECU - so I reckon you will be running on a bog standard range rover map at the moment.

zombeh

695 posts

216 months

Monday 28th June 2010
quotequote all
Barkychoc said:
The tune resistor selects different maps in the ECU - so I reckon you will be running on a bog standard range rover map at the moment.
Worse than that it's on the Limp Home map if it hasn't got a resistor.

here's one I took out of the car tonight

Ragtop

592 posts

230 months

Monday 28th June 2010
quotequote all
Here's another picture of what to look for:

http://www.rimmerbros.co.uk/Item--i-PRC8172

Last time I was fiddling with the ECU I seem to recall it was fairly accessible in the mess of wiring harness in passenger footwell. They are readily available from LR dealers - google PRC8172 for the green (non-cat) one for example.

Good luck,
Graham

Oldred_V8S

Original Poster:

3,764 posts

267 months

Tuesday 29th June 2010
quotequote all
Thanks all for your feedback, hoping that one will arrive tomorrow, just need to delve into the rats nest in the footwell to find it.

Cheers,
Paul