Fiero cruise servo not strong enough

Red · Post by **Red** » Tue Nov 06, 2007 10:51 am

The car: 3800 supercharged Series II with stock Fiero cruise control

I noticed that my cruise control isn't working properly. Determined that the cruise servo isn't strong enough to open the throttle plate on the 3800. When I removed one of the 2 springs on the outside of the throttle plate, it opens easier and cruise works properly now.

I've tried a few different cruise servos and they all behave the same. Anyone else run into this issue? Is there a way to make the servo stronger? Or have other just removed one of the throttle plate springs?

The Dark Side of Will · Tue Nov 06, 2007 1:34 pm

Looked for vacuum leaks?

Series8217 · Post by **Series8217** » Tue Nov 06, 2007 4:12 pm

You could switch to the electric servo cruise control used on mid-90s+ GM cars..

Red · Post by **Red** » Wed Nov 07, 2007 9:18 am

The Dark Side of Will wrote:Looked for vacuum leaks?

All hoses are new and I can't find any sign of vac leaks. Idle is nice and smooth.

Red · Post by **Red** » Wed Nov 07, 2007 9:18 am

Series8217 wrote:You could switch to the electric servo cruise control used on mid-90s+ GM cars..

Will the servo off a 1990 Grand Am work?

The Dark Side of Will · Wed Nov 07, 2007 9:42 am

Not sure when the electric cruise was introduced, but if it looks anything like the servo that's on your car now, it's vacuum.

Have you checked your *servo* and vacuum reservoir for vacuum leaks?

Is your throttle body the stock 3800 piece? I can't believe that no one's had this issue before... I would have expected someone to have encountered it. That's why I'm really thinking that there's something wrong with your cruise system...

Mickey_Moose · Post by **Mickey_Moose** » Fri Nov 09, 2007 12:36 pm

The Dark Side of Will wrote: Have you checked your *servo* and vacuum reservoir for vacuum leaks?

Also check the coil/solenoid on the servo...I have seen a few where the plunger was rusty and causing some problems as well (far from water tight).