Powermaster changeover question

[rsinss]

I just changed over from the old Powermaster unit on my 86 GN to a new vacuum booster unit. The car now idles fast and fluctuates from 2000rpm to 4000rpm at idle in neutral and park ... a little lower rpm in drive. My "Check Engine" light is almost always on except when I am cruising down the road. I suspect these issues are related to the changeover and the fact that I have the two electrical connections which formerly connected to the old Powermaster now dangling and not connected to anything, confusing the computer. Does anybody have any suggestions to remedy the idle and check engine light issues? Thanks.

 

[turbov6man]

Just the plugs being disconnected shouldn't be causing an issue. Unless they are arcing against something metal. Take some electrical tape and tape them off individually. That should be enough.
Sounds like you have other issues now. Any vacuum leaks from the install? Check engine light is on. What code?

 

[mikestertwo]

Sounds like you have a vacuum leak. Is it a known good vacuum booster you installed?

 

[rsinss]

Just the plugs being disconnected shouldn't be causing an issue. Unless they are arcing against something metal. Take some electrical tape and tape them off individually. That should be enough.
Sounds like you have other issues now. Any vacuum leaks from the install? Check engine light is on. What code?

I haven't checked those things yet but I'll give it a try ... thanks for your reply.

 

[salvageV6]

If you don't have a scanmaster, read the codes the old fashioned way with a paper clip.

Search feature here should have the procedure or else over at gnttype.org.

 

[rsinss]

Sounds like you have a vacuum leak. Is it a known good vacuum booster you installed?

Got everything from GBody Parts ... all new. Pretty sure parts aren't the issue.

 

[rsinss]

If you don't have a scanmaster, read the codes the old fashioned way with a paper clip.

Search feature here should have the procedure or else over at gnttype.org.

Thanks, i'll give it a try.

 

[lightningdan]

hey guys, im a total newbie but i was wondering, is there a check valve in line? do u guys use check valves inline with the brake booster?

 

[mikestertwo]

hey guys, im a total newbie but i was wondering, is there a check valve in line? do u guys use check valves inline with the brake booster?

The fitting that plugs into the booster is a check valve.

 

[gmmuscle]

Where are you picking up your vacuum signal. If you replaced the factory block with the billet with the extra fitting, unplug your connection and cap it off. See if the engine still idles erratically. I had no problems doing the conversion using an Advance auto unit and modifying brake pedal. Like was said earlier- wrap the 2 plugs with tape.

Carl