turbo 400 vacuum modulator

[butch32]

Did the M1008 and M1009 have adjustable vacuum modulaters? If so where they adjustable by screwdriver or allen wrench. Would like to adjust mine as it shifts at 17 and 35 which I think is a little high for a M1008 with 4.56 gears.

 

[xenocath]

the stock one on my truck did not have an adjustment the napa one i replaced it with had a flat head screw inside the tube where the hose hooks up.

 

[raiburn]

If yours has a screw, back it out a turn or two.
If it was mine, I would adjust the vacuum valve on the side of the injector pump towards the fire wall a little. Joe.