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3.5 swap How can I eliminate the mid range dead spot?

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Old 12-13-2007 | 07:53 PM
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I have zeitronix zt-2 WB setup. I have tuned my 99 with 00VI perfectly and with ease. The 98 3.5, not so much.
Old 12-13-2007 | 07:56 PM
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. . . .
Old 12-13-2007 | 07:57 PM
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The data and AF ratio is comming to the laptop, but when I make adjustments on the SAFC2, the graph doesnt shift. Hell, my friend and I were messing with it, first we did a baseline at 0, then we took it down to like -8ish% give or take, ran it, then check graph, nothing. Moved it down more to -20, run, check, nothing. Okay, Hell, lets try it all the way, LOL(I know), -50, run, check, nada. Doesnt even budge from the original line. Im gunna try putting in a VAFC2 and see if anything goes.
Old 12-13-2007 | 08:00 PM
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Is the MAF wire connected? (And reconnected?)
Old 12-13-2007 | 08:05 PM
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Wouldnt my car run like **** if it wasn't on either end?
Old 12-13-2007 | 08:22 PM
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Probably.
Old 12-13-2007 | 08:30 PM
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Well, it runs perfectly fine, thats why Im stumped. Perhaps if I get it tuned correctly, there would be less of the dead mid range spot, and my gas mileage would be much better. F This, Im gunna try a VAFC2.
Old 12-13-2007 | 08:49 PM
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IMO, your dead spot is not from the AFC, you bigger problems, -50% and no change in AFR =
Old 12-13-2007 | 08:51 PM
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yea, i also noticed the obvious.... , but what im saying is that, it might help out with both issues, once it is working correctly. I guess time and effort will tell....
Old 12-15-2007 | 11:02 AM
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Are you able to record the MAF voltage? If the VAFC was working correctly the MAF voltage should be altered right?
Old 12-15-2007 | 10:30 PM
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He'd have to graph the maf voltage related to something though (rpm & tps) pre & post corrections to see if it was doing anything, and that would basically tell him what he is already seeing....... or monitor the maf voltage before & after the afc. I'm sure for one reason or another the maf voltage is not being altered though, the only thing I could think of is either a bad afc or you tapped into something other than the maf wire.......
Old 12-22-2007 | 09:16 PM
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okay I changed out the SAFC2 to a VAFC2, soldered all the wires and electrical taped over it. We tried to tune it again, and it still does the same ****, NO RESPONSE or change in the graph, WTF!
can I run a wire straight from the MAF to the VAFC2 and bypass everything else? lol

what could affect my problem, fuel pressure? size of fuel injectors?, what else?
Old 12-25-2007 | 09:31 AM
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Try measuring continuity from the maf wire underhood directly to the wire you are hooking the vafc up to to confirm you have the right one. What color & pin # is it?

No codes right?
Old 12-25-2007 | 12:28 PM
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Its like pin 55 i think and it is white. and there are no codes.
Old 12-27-2007 | 09:48 PM
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Update: I double-quadruple checked the pin, according to Jimes SAFC diagram, it is pin 54, I double checked the connection on mine and I have the MAF also wired up at pin 54. Check this out, my friend decided to unplug the VAFC2 from the subharness, and the car died, I'm assuming I have the MAF wires correctly hooked up.

Next step, we turned the fuel pressure down from 30PSI idle to 20psi @ idle. Went for a little drive. 4th gear pulls = 13.8-14 AFR across the whole rpm band. Nice. We try to add fuel [up on the VAFC(positive)], go for a little drive, and NOTHING. WTF!. Well at least my gas mileage should skyrocket now!, SCORE!

Next time around we are going to run a wire straight from the MAF connector to the VAFC2 and from there into the ECU. Can anyone tell me which wire color is which on the MAF connector? Does the white wire from the connector run all the way back to the ECU or does it change over colors on the way? Black wire at the MAF connector, I'm going to assume is ground. What is the red? Live; aka power? and the white is data? Enlighten me please. THanks
Old 12-27-2007 | 10:13 PM
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Old 12-29-2007 | 12:01 AM
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anyone?
Old 12-29-2007 | 03:22 PM
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White is signal wire which should run all the way to the ECU. Red is power, Blk is ground.
Old 12-29-2007 | 08:10 PM
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good, thanks
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