Welcome Visitor! Please take a few seconds and Leigh
New Member
- Joined
- Jul 20, 2011
- Messages
- 25
- Reaction score
- 0
- Points
- 1
- Vehicle Year
- 1999
- Make / Model
- Ford Ranger 2WD
- Transmission
- Manual
HISTORY: Less than 500 miles since bought used.
From previous owner, there was less than 100 miles on the following parts, as related to “tune-up”:
NEW: Ignition coil, Timing belt, EGR Pressure Sensor, EGR Valve, Spark-Plugs, Ignition wires, Ignition Coil, O2 Sensor, MAP Sensor, & Inlet Air Filter.
From the start, the idle was slightly rough, & the Check Engine light was on.
The code indicated an IAC problem, but after replacing two IAC’s, the light remained on.
Subsequently I cleaned & checked the MAF, the IAC plug & wires, and the TPS (though I didn't do a voltage check on the TPS).
There are no notable vacuum leaks-- Indicates 17-18 psi at idle
There was some “sludge” build-up at the throttle-body / valve, so I removed the TB, and thoroughly cleaned the bore, and valve with CRC TB cleaner & a tooth brush, and reinstalled it.
The CE light didn't come back on, & I thought the problem was solved; but the idle RPM seemed high, so I backed off on the Idle adjustment screw until it seemed about right; but after driving it some the idle RPM seemed too low, so I turn it up some, and the CE light came back on indicating an IAC problem again.
I decided to turn it back down ½ turn at a time in an attempt to get a “smooth” idle without an IAC fault. It ran OK for about 100 miles, with no CE light, than the rough idle problem started again.
EXAMPLE: The other day, it started right up in the AM, I drove to work, making several stops on the way, with no problems.
I left work, it started right up and ran fine; I got to the first traffic light I stopped and it suddenly ran rough and quit. After multiple cranking, it finally started up again, and ran fine all the way home.
I stopped at my mailbox—idled just fine--- I stop in my yard—continued to idle fine.
I haven’t been able to find any info on idle adjustment? If the throttle valve is supposed to be fully closed at idle, what is the mechanical adjustment screw for, and how do “you” set it?
Leigh
From previous owner, there was less than 100 miles on the following parts, as related to “tune-up”:
NEW: Ignition coil, Timing belt, EGR Pressure Sensor, EGR Valve, Spark-Plugs, Ignition wires, Ignition Coil, O2 Sensor, MAP Sensor, & Inlet Air Filter.
From the start, the idle was slightly rough, & the Check Engine light was on.
The code indicated an IAC problem, but after replacing two IAC’s, the light remained on.
Subsequently I cleaned & checked the MAF, the IAC plug & wires, and the TPS (though I didn't do a voltage check on the TPS).
There are no notable vacuum leaks-- Indicates 17-18 psi at idle
There was some “sludge” build-up at the throttle-body / valve, so I removed the TB, and thoroughly cleaned the bore, and valve with CRC TB cleaner & a tooth brush, and reinstalled it.
The CE light didn't come back on, & I thought the problem was solved; but the idle RPM seemed high, so I backed off on the Idle adjustment screw until it seemed about right; but after driving it some the idle RPM seemed too low, so I turn it up some, and the CE light came back on indicating an IAC problem again.
I decided to turn it back down ½ turn at a time in an attempt to get a “smooth” idle without an IAC fault. It ran OK for about 100 miles, with no CE light, than the rough idle problem started again.
EXAMPLE: The other day, it started right up in the AM, I drove to work, making several stops on the way, with no problems.
I left work, it started right up and ran fine; I got to the first traffic light I stopped and it suddenly ran rough and quit. After multiple cranking, it finally started up again, and ran fine all the way home.
I stopped at my mailbox—idled just fine--- I stop in my yard—continued to idle fine.
I haven’t been able to find any info on idle adjustment? If the throttle valve is supposed to be fully closed at idle, what is the mechanical adjustment screw for, and how do “you” set it?
Leigh
