Hi all, I took my intake piping off my TT today to clean the throttle bodies and after doing so I've noticed that the butterflies are not in the same closed position. Since I have a few idle issues I want to fix it up. I know how to adjust the closed position limit on each side but I'm just trying to work out which side is correctly positioned as a reference. At the moment I think my right hand side butterfly is in the correct spot, closely lined up with what I'm thinking is a vacuum port. Here is the passenger side butterfly. And here is the driver side butterfly. As you can see its a good 2-3mm further away compared with the passenger side. So my question is should the driver side be closer to that mark/vacuum port?
Paper test is what most use They should be the same - there is no side that is a reference side as they should both be correctly positioned People use the paper slide test to position them rather than worry about how close they are to the venturi - this means when the throttle is closed the paper does not move but when the throttle slack is taken up slightly (just enough to start them moving) the paper slides in and out (just) and is equal on both sides in the pressure required to move the paper! That is how they are adjusted equally - its very fine in tuning but its easily done with a bit of patience and a piece of paper strip and they should then appear equal to the venturi Makes a big difference to economy and power so your car should see the improvements when done! Good luck JC
FSM page EM-23 is where you want to be. Can be a bit involved, but is the 'right way'. http://www.300zx-twinturbo.com/cgi-...=0&cycle=off&slide=23&design=default&total=70
Yep ^ This. Except i dont bothger with funky bits of paper. Gotta make sure that the cross linkage is having no influence on the butterfly's position. My ghetto method is to just release the back stop screw until the butterflys "bottom" and the screws go loose, then wind the screws back until they just contact the butterfly lever. After that I just wind on them equally until the idle speed approaches what its sposed to be. Then just make sure that the cross linkage opens both butterflys exactly together. Been working for me for a long time. E
I don't think the cross linkage is causing any issue. They appear to be synchronised when fully open, I've measured it as well and they're both in the same position. But the closed throttle limiter screws on the left sides of each body are set differently.
Exactly. So set them the same b ut make sure that the linkage doesnt affect anything while ur doing ur adjustments. The linkage is the LAST thing to adjust. E
Well its all adjusted now. Have both sitting at the same spot open and closed. Needed to synchronise it a little. Probably have to mess around with the TPS again But battery is flat and can't be bothered jump starting her today, its getting dark haha. 300ZX lyfe haha.
Here is a good article that may help I found this article a while agao when i did my plenum pull. It may assist with your efforts or at least double check what you have done. MichaelZ
Thanks for the input all. I have managed to sync the butterflies. But need to readjust the stop screws. The idle is rock solid now, but too high, about 1400rpm. Tested out if the IACV needed to be adjusted by unplugging it entirely, still sits at 1400 and I checked the hard idle switch and its on. So pretty certain I just need to set the closed position a little more closed, then its all good
