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Electronicals / Forscan Expert
Joined: Fri Nov 24th, 2017
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It's been 100k miles since spark plugs and wires so I went ahead and swapped those out. Motorcraft plugs as always and the older plugs looked great (good color no deposits). Cleaned the throttle body butterfly while I was at it.
Did a compression test immediately after a drive to get temps up to normal. Throttle body held open:
cyl 1: 185
cyl 2: 180
cyl 3: 180
cyl 4: 170
Before removing wires I used a grounded test light to test all coil pack towers. All had good color spark and bright and was able to spark to about an inch away from the towers.
ST and LT fuel trims look great at closed loop. LT stays right at 0 and short term may be a max of postiive 4% to min of negative 3%. So I'm not thinking bad injector.
So I removed the IAC leaving the connector connected, fired up Forscan and started changing the IAC duty cycle. I can't see any changes. Do hear a little noise but no movement. IAC is closer to cylinders 4 and 3 so I could see this valve not being opened enough and starving cylinder 1 and sometimes 2. Ohmed out at 10 ohms.
With nothing connected the plunger it does allow some light though.
Anybody looked at the movement of the IAC before?
Last edited on Mon Jan 15th, 2018 02:24 pm by sheltonfilms
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2000 XLT 2.5L A/T 2WD
Mods:
Power Windows/Locks Mirrors using OEM harness and parts
Explorer Sportrac White Face Cluster
Explorer OHC and Auto-dim Mirror
Auto Door Locks
Full HID Projector Retrofit