Made IAC restrictor plate...now what?

[mustanggt94]

I did the searches to fix my hanging idle, and determined that the only thing left to try was this IAC restrictor plate. I made one and installed it yesterday, and now NO MORE HANGING IDLE! Yay! Well, the only problem was that I wasn't sure the best way to adjust my idle after I installed the plate, so I left the IAC screw out all the way and adjusted my idle using the throttle plate screw. The hole I drilled in the IAC plate was the smallest recommended (5/32") so I figured I would not want to restrict it any more by using the IAC adjustment screw.

Well, now my problem is that the car is VERY hard to start when warm and surges like crazy when I do finally get it started and continues for about 30-60 seconds and then it runs just fine. At cold start it runs better than ever and no hanging or surging. I checked the codes (even though I am not getting a CEL) and I pulled a 121-"TPS out of range", 334-"EVP sensor is/was high", and 565-"Canister Purge 1 solenoid/circuit failure - Solenoids"

I'm not concered with the EVP sensor since I am not using an EGR valve, but the Canister Purge 1 gives me a little concern as does the TPS sensor code. BTW, I have replaced my TPS with a new OEM Ford one recently and I have also tried using other IACs (not new, though).

 

[gcomfx.com]

Did you unplug your battery and let it clear it's memory out? (Pump the brakes a few time, turn on the headlights, etc. with battery unhooked.) If not, do this.... and then drive the car a few days and pull the codes again.

The TPS code is not good.... but just changing the TPS out won't always fix it if the computer still thinks the old broken one is in there.

 

[mustanggt94]

Did you unplug your battery and let it clear it's memory out? (Pump the brakes a few time, turn on the headlights, etc. with battery unhooked.) If not, do this.... and then drive the car a few days and pull the codes again.

The TPS code is not good.... but just changing the TPS out won't always fix it if the computer still thinks the old broken one is in there.

Yeah I did that but maybe I didn't unplug it long enough. I did replace the battery since I did the TPS, so that shouldn't be it. I think that I am getting the TPS code because I adjusted my idle using the throttle plate screw. I will try clearing the codes and resetting my idle the correct way and see how she runs/check the codes again when I get home today.

 

[gcomfx.com]

I have a plate in mine.... and the idle screw is about out as far as it'll go. Then I've also bumped the throttle plate screw a bit. Idle is good now. But it would be nice if I could lower it just a tad. It seems no matter what I do, I can't get it to idle less than 1,000 on the dot.

 

[mustanggt94]

I have a plate in mine.... and the idle screw is about out as far as it'll go. Then I've also bumped the throttle plate screw a bit. Idle is good now. But it would be nice if I could lower it just a tad. It seems no matter what I do, I can't get it to idle less than 1,000 on the dot.

Me too! I got my idle to 900 right now but of course I am having this hot idle problem. I figured since my hole is only 5/32" my idle would be too low if anything. Weird!