Real Fiero Tech

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?

Looked for vacuum leaks?

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

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.

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?

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...

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).