Flat spotting...

How do you do it? Maps etc..

Flat spotting...

Postby beachbuggy61 » Mon Jan 02, 2012 1:54 am


Couldn't think of any other way to describe it, hence the flat spotting topic name.

I've got a Type 1 1915 with a single GT3 Porsche turbo running into quad throttle body CB performance fuel injection with EDIS ignition, a Tech Edge O2 controller and an MS2 controller.

I got a basic fuel map set up and have been using the auto tune function on Tuner Studio to get it right. This is really starting to come together. The more I drive, the better it gets. In fact when it's running right it's a joy to drive, very smooth and powerful. My problem is that it stutters and flat spots when I put my foot down, even gently. In my old carburettor days, I would say it's 'bogging down'. It does this quite severely, to the point that as I'm blatting the throttle on the sand dunes, it bogs down so badly that I have to put the clutch in, rev it til it clears itself and then go again. Not fun when you're trying to get up a dune or squirt around in the soft stuff! It also does this on the road. If I bury my foot off the line, I can get good up-shifts, but if I try to drive like a normal citizen, it stutters and carries on a treat!

If I had carbies, I"d be thinking that maybe the accelerator pump jets are too big, but with EFI I don't know. I'm very new to EFI. Could it have something to do with accelerator enrichment? Or is at a fuel map problem? I think the fuel map is getting right though because auto tune is making less and less adjustments each time I drive it.

Hopefully someone might have a suggestion, because other than this problem, everything is going really well and the car is fun to drive.

Attached a picture, just for the hell of it! :D

Any help appreciated. Many thanks, Marc.
Baja on Stockton.JPG
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