Vacuum, intake, pcv leak? 02 ranger 3.0

[shanep1987]

I have been having a rough idle issue for the last few weeks after the truck gets warm. I think the only thing left that i havent replaced or ruled out is a vacuum leak.

I can hear a slight hiss around the intake pcv area on the drivers side. I have went through 2 cans of carb cleaner around the engine/hoses including that area trying to listen for a change in idle. Another thing is i pulled the pcv valve and shook it(it ratlles) and also put my finger over the hole in the intake there was no change in idle. Also put my finger over the valve itself and felt vacuum but there was no change in the rough idle. Normal?

I have also hooked a hose to the brake booster and blew smoke in it, found no leaks other than the breather hose from intake which i replaced.

What am i missing?

 

[RonD]

I assume you have cleaned the IAC(idle air control) valve, it is a controlled vacuum leak used to set and change idle speed.

Are you burning more fuel than normal?
Fuel injected engines use an ECT(engine coolant temp) sensor as the "choke", this sensor tells the computer the engine temp, when cold, computer runs engine rich, like a choke did, as engine warms up less fuel is injected.
If ECT is stuck at "cold" the engine would run fine until it warmed up, and it might not set any codes since the ECT also tells the computer when to switch to "Closed loop" and use the O2 sensors.
The ECT is a 2-wire sensor located near the temp sender(1-wire) for the dash board gauge, both are near the t-stat housing.
The ECT can be tested with an OHM or Volt meter

The Ford Coil is actually 3 coils, 1 of the 3 coils can fail and can cause misfires on 2 cylinders, these can be heat sensitive so only noticed when engine warms up.
Coil pack can be tested with an OHM meter

Could the "hissing" be a squealing, have a read here:
http://www.therangerstation.com/tech_library/camshaft_position_sensor.html
Although this probably would not be temp sensitive

 

[shanep1987]

I may be getting a bit worse gas mpg, but I was just assuming it was from chasing this issue, and it sitting and idling so much.

Now I think I MAY have found the issue, now doing a backyard smoke test revealed that the throttle body shaft seal has a small leak. While pulling n pushing on it I noticed I could actually increase or decrease the idle..somewhat smoothing out the idle. Problem is I don't want to pay for a new one!! And I'm at a loss for what is compatible with a 2002 3.0. From what I've read I'm pretty much screwed on finding a replacement...what y'all think?

 

[RonD]

You could find another at an auto recycler, but the throttle body can be removed, disassembled and most likely repaired.


This is a thread if you want to go to a larger throttle plate
http://www.fordrangerforum.com/3-0-vulcan-tech/53055-2002-3-0l-throttle-body-mod-50mm-60mm.html

 

[shanep1987]

Any good ideas on where to find one or any tips on fixing it?