Hey everyone.
I own an ef fairmont and iv been trying to find out why it wont rev over 3800rpm.
Iv traced it to the solenoid that controls the vacuum to the diaphragm that controls the butterfly in the broad band manifold.

Its not the solenoid itself as iv replaced it with a new unit. Its opens when ignition is on and so on as it should.

Iv tried my best reasearching the site. But iv found conflicting information on which pin controls the signal for the solenoid. I know the positive is just straight 12v. So it must be negative feed from ecu. So far from what iv found it could be pins 15 or 49?

It would be much appreciated if anyone could shed some light on which pin is the right one and if another sensor malfunctioning may cause the ecu to make the solenoid do this.

Cheers, Eddie

Last edited by eftickfordfairmont on Sun Aug 08, 2010 7:22 pm, edited 1 time in total.

it wouldnt be the solenoid at fault, its either a vacuum leak (split hose or broken tee) and also there is a check valve that holds vacuum for the dash that could be not working correctly. Easiest fix for that is to install another check valve inline with the vac line that goes to the dash.

Iv checked the hoses in water.

Over the past 2 weeks iv been observing and playing around.

Iv found that its not the Solenoid or the wiring.
The hose keeps holding vaccum thats the problem.

I understand that the hose should continue to hold vaccuum via the check valve.
But how does it then release? when the solenoid closes.

I was thinking maybe the bbm diaphragm has a very small bleed hole???

ANYONE?