traildog
New Member
- Joined
- Oct 14, 2019
- Messages
- 12
- Reaction score
- 11
- Points
- 3
- Location
- Missoula, Montana
- Vehicle Year
- 02
- Make / Model
- Ranger FX4
- Engine Type
- 4.0 V6
- Transmission
- Manual
- 2WD / 4WD
- 4WD
- My credo
- 42
Been awhile since I was on this forum, but looking for some diagnostic help. My 4.0 has developed an idle problem, which I assumed to be a vacuum leak as it's had a few of those in the past. But the carb cleaner/propane test doesn't bump up the rpms and if I disconnect the IAC it dies immediately. I replaced the IAC for good measure to no avail.
This morning it was doing something interesting- idling at 2000 rpm, then every 5 seconds it would rev up to 2500 for a few seconds and then come back down. No input to gas pedal during this. It kept in this pattern for minutes so I took a video:
I guess next on the list is to clean the throttle body and MAF sensor. But maybe the cyclical revving indicates something in particular?
Appreciate any help.
This morning it was doing something interesting- idling at 2000 rpm, then every 5 seconds it would rev up to 2500 for a few seconds and then come back down. No input to gas pedal during this. It kept in this pattern for minutes so I took a video:
I guess next on the list is to clean the throttle body and MAF sensor. But maybe the cyclical revving indicates something in particular?
Appreciate any help.