High idle

OK, over the last week or so, I have replaced the isolator bolts, the DPFE, spark plugs, engine/transmission oil and filters. Now the car is idling high and I can’t get it to slow down. It was working fine for the first 10 starts or so (after completing all this work) but now I have this issue. It idles at about 1500 RPM in drive and 2000 in park. I can coast about 45MPH without pushing the gas petal. I do here a large sucking sound coming from the front of the motor (passenger side of engine compartment) but I can’t isolate it. I triple checked all the vacuum lines and can’t find any off and I’m fairly certain the intake was re-installed properly or I would have noticed this on the first start. I probably have 20-30 starts on the car since the battery was plugged back up and I haven’t got any trouble codes yet.
What controls the butterfly valves in the intake? Could they be stuck open?

Hi
I had a much older vehicle('87 Tempo) with high idle. Turned out to be nothing more than a failed PCV valve. Check yours carefully as it is on the valve cover closest to the firewall - in the area where you are hearing the hissing/sucking sound.

PROBLEM FIXED,
your not gonna believe this crap.

I took off the Idle Control Valve and it had a piece of a twig stuck in the pintle keeping it open about 1/8". Reinstalled it and it idles fine now. I know I should probably remove the intake plenum and check for more debris, but I’ve run out of time. I'll have to let fate run it course on my long road trip tomorrow.

I guess it got in there while I was washing oil out of all the parts while I did the 171/174 fix a few days ago.
Wish me luck.
TOM

Hey good find. My older car had throttle body fuel injection as opposed to port. Not sure how a clogged/non-functioning PCV would affect our machines. By the way: I'll belive anything!

Hello

What about the sucking noise from the front of the engine?

Regards

Dan

I don't know where that sucking sound was coming from. It went away when the idle RPM dropped. The car idles smooth and accelerates fine. Must have just been normal engine noise?? We’ll find out if it affects me on the trip.