Uncle Gump
Token Old Guy
TRS Event Staff
TRS Forum Moderator
Supporting Member
VAGABOND
TRS Event Participant
TRS 25th Anniversary
- Joined
- Sep 17, 2018
- Messages
- 14,032
- Reaction score
- 13,563
- Points
- 113
- Location
- Ottawa IL
- Vehicle Year
- 2006/1986
- Make / Model
- Ranger/BroncoII
- Engine Size
- 4.0L SOHC/2.9L
- 2WD / 4WD
- 4WD
- My credo
- Lead follow or get out of my way
With vacuum gauge connected... check vacuum at idle. Then increase RPM to about 3000 RPM. Vacuum gauge with likely increase slightly from idle reading. Blipping the throttle will drop vacuum to zero... but should increase as RPM rises and is held steady. If it wont... restricted exhaust.
Plugs being clean/white... sounds a bit lean.
My 2.9L at idle...
It's north of 40 psi with no vacuum. If your gauge is accurate... lower pressure = leaner mixture. O2 sensor can compensate mixture to a point... but would likely set a code in extremes.
Plugs being clean/white... sounds a bit lean.
My 2.9L at idle...
It's north of 40 psi with no vacuum. If your gauge is accurate... lower pressure = leaner mixture. O2 sensor can compensate mixture to a point... but would likely set a code in extremes.