Lance J

how do you lean out the fuel on a CIS. i have a 1979 us 5 speed. I want to turn
down the fuel.

Dennis Wilson

The A/F mixture is adjusted with a 3mm long hex (allen) wrench. It is inserted into the opening in front of the fuel distributor. To lean it, you turn the wrench CCW in very small increments. If you go too lean the result will be an overheated engine, detonation and or blown head gaskets.

Why do you want to lean it out? Have you checked the control and system pressures to see if they are within spec? Have you done a general tune up? Checked for leaking injectors, etc. i.e. the A/F mixture is very constant in the CIS system and should be adjusted only as a last resort.

jpitman2

You need to push the allen key down to engage the adjuster. Note that the pressure of this can affect the mixture, so push down, feel the engagement, make a change, release the down pressure, check the result. ITS VERY SENSITIVE, MAKE SMALL CHANGES!! Like 1/12 of a turn at a time....

jp 83 Euro S AT 51k

Lance J

okay thanks guys. i have my reason for dailing it back. but once i confirm i think i have a upgrade that can put the OB's back on top. i will be posting pictures ones i get all my senors, gauges and other tools to track the progress and tune to keep records of my gains so no one will question this upgrade

Charley B

You have my attention.

918-S

Lance J

i'm looking to purchase that digtal WUR. One other thing i must have nail down. Is a good way to increase and decrease vaccum

SMTCapeCod

What? You mean an artificial vacuum modulator? I think that boost controllers for turbo cars work that way...do you mean just for a signal for some sensor or actual manifold vacuum..but you've got me baffled from the outset with a power added that you need a leaner fuel mix for..but I look forward to hearing about the results fo the digital wur, I keep hearing that they are on the brink of the next great upgrade...