cavity.
New Member
- Joined
- Jul 12, 2016
- Messages
- 4
- Reaction score
- 0
- Points
- 0
- Vehicle Year
- 1997
- Make / Model
- Ford
- Transmission
- Manual
First off, been reading this forum religiously since I got this truck so I appreciate all the posts. I wish I had more to contribute myself Now to my problem...
Symptoms:
P1506 Check engine code (Idle Air Control Overspeed error)
Slow to rev back down when I step on the clutch or put it in neutral. Usually have to wait till I fully come to a stop for it to slow down
I'm not sure what my actual idle rpm is, but it does sound a little high. I ordered a tach which is on the way.
Things I've done:
1. Checked for intake leaks, sprayed all over with carb cleaner -- found nothing
2. Replaced MAF sensor with clean one from junkyard (cleaned it too) -- no effect
3. Replaced IAC with what looks like a brand new one out of an explorer from junkyard-- no effect
4. Replaced PCV Valve (old one seemed ok, but figured it was worth a shot)
5. Disconnected IAC -- no effect on idle !!
6. Measured TPS Voltage: Measures 1.04V to 4.76V
So my questions:
What does it mean if disconnecting the IAC has no effect on idle? (I do get a P1504 IAC circuit malfunction code when i disconnect it)
I have a theory that the idle screw was messed with by previous owner because it was misfiring when i got it (he had two plug wires swapped). He might have increased the idle to prevent the engine from dying while misfiring. Is 1.04V high enough to assume this might be the case? Can I just release some tension in the throttle cable and call it a day?
Symptoms:
P1506 Check engine code (Idle Air Control Overspeed error)
Slow to rev back down when I step on the clutch or put it in neutral. Usually have to wait till I fully come to a stop for it to slow down
I'm not sure what my actual idle rpm is, but it does sound a little high. I ordered a tach which is on the way.
Things I've done:
1. Checked for intake leaks, sprayed all over with carb cleaner -- found nothing
2. Replaced MAF sensor with clean one from junkyard (cleaned it too) -- no effect
3. Replaced IAC with what looks like a brand new one out of an explorer from junkyard-- no effect
4. Replaced PCV Valve (old one seemed ok, but figured it was worth a shot)
5. Disconnected IAC -- no effect on idle !!
6. Measured TPS Voltage: Measures 1.04V to 4.76V
So my questions:
What does it mean if disconnecting the IAC has no effect on idle? (I do get a P1504 IAC circuit malfunction code when i disconnect it)
I have a theory that the idle screw was messed with by previous owner because it was misfiring when i got it (he had two plug wires swapped). He might have increased the idle to prevent the engine from dying while misfiring. Is 1.04V high enough to assume this might be the case? Can I just release some tension in the throttle cable and call it a day?