I guess I should explain - I've been making this same trip every day to
work since April and I never got below 12, usually in the 12.5-13mpg
range. Most people said that the MP PCM would improve mileage, mine
went down by 2-2.5mpg, that's like 15%+. I expected it to be about the
same or +1mpg. But as another individual said, it's still learning. It
takes me a month to burn through a tank of gas so that isn't helping either.
I think I need to take it out for a longer drive at higher speeds than a
max of 35mph to get the PCM "tuned in" properly. I'm also considering
replacing my O2 sensor as the one in there I'm sure is the original with
137k on it.
That and spending a couple hours yanking out fence posts on this tank
probably didn't help either... doh. Funny how your wallet taking a hit
makes you lose all sense of logic. ;)
Thanks,
MattB
(Still having sticker shock after driving a Neon for 6 years)
Ray Block wrote:
>
>> -----Original Message-----
>> From: Matt Beazer
>>
>> Wow, I hope I didn't fill the tank all the way up last time I filled up
>> and reset the trip odometer out of habit... because 182.5 miles on 18.8
>> gallons of fuel really sucks for fuel economy with this MP PCM, even if
>> my speedometer does read 4mph high at 30mph (8.82% off).
>>
>
>
>> If I take into account the speedometer being off...
>>
>
> Perhaps you're not aware that different speedometer gears are available to
> correct for non-stock tire diameters?
>
>
>> ....that still means I really only went
>> 198.6 miles, which is only 10.56mpg (admittedly all short trips, less
>> than 3 miles per cold start).
>>
>
> Help me understand this, Matt. You drive "less than 3 miles per cold
> start" and you are blaming an MP PCM for crappy mileage???????????? Do you
> really need an explanation?????
>
> FWIW, my Dak's gas mileage improved when I installed the MP PCM. However,
> I do drive it far enough at a time to get the engine warm and off the "cold
> enrichment" from the PCM. :)
>
> Ray
> http://www.dragtruk.com/ENTRIES/20KM1FD2KWBP.html
>
>
>
>
>
>
>
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This archive was generated by hypermail 2b29 : Sun Nov 01 2009 - 00:12:06 EDT