- Joined
- Oct 27, 2020
- Messages
- 120
- Reaction score
- 65
- Points
- 28
- Location
- Oahu, Hawaii
- Vehicle Year
- 1991
- Make / Model
- Ford Ranger
- Engine Type
- 4.0 V6
- Transmission
- Manual
- 2WD / 4WD
- 4WD
Still having an issue with high idle.
I checked for vacuum leaks all around the throttle body (including all hoses) with no luck. Doesn't appear to be any vacuum leaks.
Next, I went ahead and replaced the following with NEW PARTS: IAC, MAF, MAF pigtail, throttle position sensor, PCV valve, intake air temp sensor. Parts were replaced after motor had warmed up. RPM was checked after each component was replaced. AFTER replacing all parts engine speed dropped down to a SMOOTH 1000 RPM during idle. Ok, I can live with that. Mission accomplished. So I thought....
Next day take truck out for drive and it seemed to have a mind of its own. When I get to a stoplight and stop, initially engine speed is about 2000 then settles to about 1500 within 15 seconds, sometimes a little lower. Sometimes it doesn't drop. Has not hit the 1000 RPM mark since I did the replacement. When idling high, I disconnected the IAC harness and there was no change in idle.
Basically, Im not getting a consistent behavior. The idle speed is all over the place and has not reached the 1000 RPM mark since the day I did the replacement.
The only two things I have hooked up to vacuum are the brake booster and fuel pressure regulator. What else can I rule out before replacing the ECU which seems to be the next step?
I checked for vacuum leaks all around the throttle body (including all hoses) with no luck. Doesn't appear to be any vacuum leaks.
Next, I went ahead and replaced the following with NEW PARTS: IAC, MAF, MAF pigtail, throttle position sensor, PCV valve, intake air temp sensor. Parts were replaced after motor had warmed up. RPM was checked after each component was replaced. AFTER replacing all parts engine speed dropped down to a SMOOTH 1000 RPM during idle. Ok, I can live with that. Mission accomplished. So I thought....
Next day take truck out for drive and it seemed to have a mind of its own. When I get to a stoplight and stop, initially engine speed is about 2000 then settles to about 1500 within 15 seconds, sometimes a little lower. Sometimes it doesn't drop. Has not hit the 1000 RPM mark since I did the replacement. When idling high, I disconnected the IAC harness and there was no change in idle.
Basically, Im not getting a consistent behavior. The idle speed is all over the place and has not reached the 1000 RPM mark since the day I did the replacement.
The only two things I have hooked up to vacuum are the brake booster and fuel pressure regulator. What else can I rule out before replacing the ECU which seems to be the next step?