Strange fuelling issue - Throttle Pot?

Strange fuelling issue - Throttle Pot?

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Discussion

AceOfHearts

Original Poster:

5,822 posts

192 months

Friday 31st October 2014
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I fitted my AEM wideband today to hopefully help figure out why the car is being so heavy on fuel and also to spread the cost of the Megasquirt install that I am hopefully ordering next month, and interestingly the car seems to be running ok but with just a few anomalies that I wanted some opinions on.

-Under full throttle it sits fairly steady around 12:1 (Ok I think)
-Cruising at 60 to 70 mph it stays roughly at 14.5 but even with the throttle steady bounces between 13.8 and 15.0 every half a second or so
-Ticking over it sits steady at 14.9 four out of five times but then it will sit at 12.0 the next time I pull over. If i drive off and stop again it will go back to idling at 14.9

Judging by the fact that the ECU seems to be wanting to constantly adjust the fuelling even when cruising with a steady throttle seems to suggest to me that the TPS might be acting up, which I will check out tomorrow, but does anyone else have any ideas why it might be doing this.

Its not really a massive issue as I am ditching the 14CUX soon anyways but it would be nice to get to the bottom of the heavy fuel consumption before making the change.

Any ideas?

AceOfHearts

Original Poster:

5,822 posts

192 months

Friday 31st October 2014
quotequote all
Interesting, I didn't know that. Shame i don't have any cats hehe

AceOfHearts

Original Poster:

5,822 posts

192 months

Friday 31st October 2014
quotequote all
Cheers guys, that has put my mind at ease smile

Now i'm happy all is ok I just need to save the pennies and get the Megasquirt ordered up!



Edited by AceOfHearts on Friday 31st October 11:27

AceOfHearts

Original Poster:

5,822 posts

192 months

Saturday 1st November 2014
quotequote all
Running rich is back with a vengeance frown

As you know a couple of days ago it seemed to be running fine, today the whole way to work the AFR didn't go above 13:1, and was cruising at 12.5 at any speed.

Another strange thing i noticed it that even whilst going down hill and totally off the throttle it was still around 12.5, whereas i believe the injectors should be shutting off on overrun, and before it was going lean off the scale as i would expect?

Going to email ExtraEFI know and get the bits ordered up but I am still suspecting throttle pot maybe :/