Hello All,

I am investigating a subtle misfire type of issue and started looking for vacuum leaks.

I pulled off the wires from the IAC and the rmp drops down to maybe 600 or so. Does not idle rough once settled.

I did however notice when I tap the throttle a sucking sound that seems to be coming from the throttle body.

Of course, I do not have any carb cleaner or starter fluid or propane to look for vacuum leaks.

I have recently changed the PCV valve and will likely change the rubber tube as it is old.

Now that I have been messing with it I have thrown a code. I need to get a code reader one of these days.

So my basic question is that a sucking sound from the throttle body should be abnormal. I would think that in the previous 15 years of ownership I would have notice that.
I did take off the throttle body and inspected it for cracks and re installed it and torqued it down to spec with not change.

Thanks all,

Bob

 

Hello All,

I had my neighbor clear the code which was for the idle control valve wiring.

He thought that it sounded good and we spayed break cleaner on the vacuum hose and no affect on the idle.

So we are probably fine.

We do see some cracks in the the ignition coil so we will be changing that out.



Thanks


Bob

 

The IAC Valve has a Vent with a black cap on it
This can make a whistling or sucking sound if the valve inside is leaking a bit

The vent is there to relieve any pressure behind the valve as its pulled open and then pushed closed

The cap snaps on and off and has a small filter inside

Pictures here: https://www.explorerforum.com/forums...-w-pics.84220/

You could remove the cap and start engine then cover the port with your finger to see if that may be the source of the noise, if it ever comes back