Lambda wiring mod
Discussion
Over the year's i've tried various things to improve low throttle stability (aka "shunting"). Bodies- bearing mods, pot mods, better tune / balance etc. Even tried a new coil pack etc (the latter made no diff btw). The body mods made the biggest improvement...got close to good, but when watching the consistency of the adaptaives at idle and at very low throttle opeings (@1500 rpm you can hardly see that you've moved the butterflies !) I realised I was wasting my time...you could change the reading from lovely and stable to +/-10% different just by a brief fast idle spell (2K-2.5K ish) and then release back to idle -> adaptives would hunt to a diffent point (and hence be wrong)...eventually returning to close to where they started (meaning several minutes of dodgey running). I've had several experiences in the past where after an M-way blast, then come off to a traffic queue, the engine wanted to die on light throttle application...only to correct itself a few minutes later (would idle fine but was clearly hopelessly lean as you pressed the throttle to creep forward)
Finally tried the lambda ground mod...what a difference. Stable, easy to drive at low revs, nice throttle pick up, predictability of throttle response after a long M-way stretch etc etc.
If you haven't had it done...its a no brainer.
Finally tried the lambda ground mod...what a difference. Stable, easy to drive at low revs, nice throttle pick up, predictability of throttle response after a long M-way stretch etc etc.
If you haven't had it done...its a no brainer.
2002
4 wire
Take the heater ground wires at the plug and separate from the common spliced ground
So 2x ground wires now join instead to a separate ground feed attached to the engine using one of the timing chest cover bolts as a pick up point
I took the crimps out of the connector to make a neat job but you could just as easily snip the 2 wires and re join them to the new feed
4 wire
Take the heater ground wires at the plug and separate from the common spliced ground
So 2x ground wires now join instead to a separate ground feed attached to the engine using one of the timing chest cover bolts as a pick up point
I took the crimps out of the connector to make a neat job but you could just as easily snip the 2 wires and re join them to the new feed
Hey John...interesting
After I called you pre-xmas it set me thinking about why the engine was running like a dog after the m-way blast...and lambda mod came to mind. Well, fingers crossed, no repeat performance since re-wiring
I looked at the fuel pressure regulator as we discussed but realised the way its set up is just plain wrong...regulator is supposed to see the vaccuum from the *inside* of the buttefly to allow more return to the tank at low throttle opening => big differential pressure across injector would over fuel otherwise (in theory). But the tiv has the vac pipe to the air box i.e. outside the butterflies => I reckon that will do diddly squat. So I decided to leave well alone and checked the wiring mod first
Looks like it was the right call.
After I called you pre-xmas it set me thinking about why the engine was running like a dog after the m-way blast...and lambda mod came to mind. Well, fingers crossed, no repeat performance since re-wiring
I looked at the fuel pressure regulator as we discussed but realised the way its set up is just plain wrong...regulator is supposed to see the vaccuum from the *inside* of the buttefly to allow more return to the tank at low throttle opening => big differential pressure across injector would over fuel otherwise (in theory). But the tiv has the vac pipe to the air box i.e. outside the butterflies => I reckon that will do diddly squat. So I decided to leave well alone and checked the wiring mod first
Looks like it was the right call.Test the lambdas using a bit of carb cleaner puffed into a throttle...the lambda on that bank should go high within a second and hold there for a couple. If the adaptives continue to head north and the lambdas are proven working, you must have too much air relative to the amount of fuel-> so either too much of the former, or too little of the latter. Also try putting you hand over one throttle mouth and see what happens...should go rich i.e. lambda will go high until adaptive pulls it back down. Have you proved that correct lambda is wired to correct bank ?
The wiring mod is "finessing" only...wont help with something significant like you describe (unless of course there is a big voltage offset in the lambda path causing it to offset negatively (*very* unlikely imo)).
Try the carb cleaner test
The wiring mod is "finessing" only...wont help with something significant like you describe (unless of course there is a big voltage offset in the lambda path causing it to offset negatively (*very* unlikely imo)).
Try the carb cleaner test
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