Supercharger Discussion For all you misguided souls.
Sponsored by:
Sponsored by:

M45 Occasional Boost Loss

Old 06-04-2016, 05:09 PM
Thread Starter
Join Date: May 2016
Location: MD
Posts: 14
Total Cats: 1
Default M45 Occasional Boost Loss

Hi! I have a 1.8 supercharger, the Sebring Timing box and Powercard on my 97. When I roll onto throttle I get boost fine ( goes up to 5-6 psi with 67.5mm pulley). Sometimes it'll stick at 0psi for a split second then jump up into boost as well. However, without fail, if I stab the throttle instead of rolling into it, itll hop up to 0psi and stay there regardless of rpm and throttle position. I can have it floored and it'll feel like it was before the supercharger, yet I hear the whining still. I've gone and checked that all vacuum connections are secure, but I haven't specifically done any vacuum tests. My next thought is the bypass actuator. How could I tell if this is failing? Is it supposed to move the actuator arm when the throttle changes? Anyone have any suggestions on how to track down the cause of this?
flachattack is offline  
Old 06-06-2016, 10:05 AM
Thread Starter
Join Date: May 2016
Location: MD
Posts: 14
Total Cats: 1

Just wanted to follow up with my solution in case anyone comes across this. I installed the bypass actuator incorrectly. I installed it directly above the valve arm with no angle to it (i.e. flat). Vacuum would pull the arm up, but then never let the arm back down since the arm was not balanced/stuck in the vertical position. Jabbing the throttle during these times rocked the engine enough (and causing vacuum fluctuations) to knock the arm back down. I reinstalled the valve at an angle and my problem has gone away.
flachattack is offline  
Related Topics
Thread Starter
Last Post
Build Threads
02-04-2017 12:30 AM
Left Handed Elvis
DIY Turbo Discussion
05-21-2016 09:27 AM
Suspension, Brakes, Drivetrain
05-17-2016 05:20 AM
General Miata Chat
05-14-2016 06:17 PM
05-05-2016 10:44 PM

Thread Tools
Search this Thread
Quick Reply: M45 Occasional Boost Loss

Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.