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slomove
July 15th, 2013, 10:46 AM
I hope I am not screwed. I replaced my erratic throttle position sensor (might have been a Colvert) with a spare one that I had for a while (made by TWM). Although I recalibrated the ECU it seems to have a different response and now my fuel map is all screwed up. I had to do a mass change to enrich the middle range to be able to drive at all and now I need to all the fine tuning again to get it right. And that 2 weeks before a long trip. Crap.

Roll a 7
July 15th, 2013, 12:30 PM
Maybe you might give Bisi a shout...

slomove
July 16th, 2013, 08:57 PM
Maybe you might give Bisi a shout...

That would be an idea but given Bisi's availability a crap shot.

In the meantime I did a few rounds around the block with the foot brake dyno and logged the AFR data. I got the map almost back to good drivability and I guess another 2 or 3 iterations it is O.K..

Now here is a question for our Magnus, our mapping guru: Besides the mid range change, I noticed something that I had already with the previous TPS/map: At full open throttle I have to take back a bit of the injection time compared with the position just below. Or, to say it the other way, the max fueling is not needed at WOT, see map image below. Does that indicate, that the butterflies maybe open wider than 90 degrees and start closing again? In that case I would look for an end stop to limit the opening range.

https://lh4.googleusercontent.com/-7zeRDdJGSkU/UeYT3Vf5qyI/AAAAAAAAEGw/9PmgIZO0kQc/w1144-h794-no/NewMap0713.jpg

Doug Liedblad
July 16th, 2013, 09:33 PM
sometimes Jenvey TBs should not open the full 90, 89 or so may work better.

I read that someplace but don't remember where, maybe in the book by the guy that builds the Emerald ECU.

slomove
July 17th, 2013, 09:40 AM
sometimes Jenvey TBs should not open the full 90, 89 or so may work better.

I read that someplace but don't remember where, maybe in the book by the guy that builds the Emerald ECU.

I know of the Dave Walker book but have not read it. But that is interesting, maybe I find it somewhere on his Blog.

I am wondering the effect might be cause by the butterfly shaft disturbing the air flow when fully open.

Doug Liedblad
July 17th, 2013, 12:53 PM
I have his book and will loan / send it to you. As soon as I can find it.......