IAC restrictor plate
- Thread starter gtstangau
- Start date
triggz
Founding Member
Check all your vacuum connections and make sure you plugged everything up and that the throttle cable isnt pulled..
If that fails, replace your plate with the 22cent 'copper cap' alternative.
If that fails, replace your plate with the 22cent 'copper cap' alternative.
I have checked all the vacum lines and all that stuff and everything is fine. I have noticed from searching the forums that most of the plates have one small hole and one big one. The one I got both holes are about half the size of what they used to be. I think the IAC isn't getting enough air or something. I thought if I drove it for awhile the computer might get used to it, but the idle is still all over the place it hangs at like 1500 and then drops down to 0 and stalls out. Sounds like my foot is on the gas when I have the clutch in. Do you guys think if I took it back out and made one of the holes bigger it might help? I know a bunch of people on this site have it done and I haven't heard any other complaints. 
I hate the way my car idols 
One side of the IAC motor when you take it out is a hole, but not really. It's more like an indentation in the IAC motor. That's where the big hole on the restrictor plate goes. I have no idea what it does, or why it's there, unless there's a valve or something behind it that opens and closes that we can't see. Have you checked the hole size? Have you made sure you have a good seal between the TB and plenum? You put the gasket back in correctly? Maybe try a second gasket.
hotrodnut
Member
jstreet0204
Active Member
sgarlic said:And there's nothing gayer than a Mustang sitting next to you at a light looking at you, rev'ing his engine, and it taking 5 seconds for the rev to finish completely.
Except for one that has an idle hanging at 1500 rpm because they did this mod.
stangGT97
New Member
well i had this mod for a while but i hated how my car felt and sounded. During downshifts it popped way too much, and it made shifting harder because revs had to be matched between gears or else the car jerked. oh well, live and learn
40th GT
New Member
stangGT97 said:
You don't like the sound of pops? Man
I can't live without my IAC cap. I took it out to go to a dealer once recently and I seriously couldn't shift. It dropped to slow, I lurched on every shift. The rpms drop way, way, waaay too slowly on these things. Unfortunately, the restriction only sort of helps too... a lot of side effects, but it's better than nothing.
However, idling at 1500 rpm doesn't make any sense. Putting a plate in front of the air flow wouldn't INCREASE the air flow no matter what it's doing. Most likely there is a leak somewhere. If you are using the plate and it's metal on metal, that is likely a bad seal. Try out the copper cap to avoid those problems (I had to switch from the plate to the cap because I couldn't get a good enough seal, even with gasket material)
hotmustang331
Active Member
I just redid myPCV system...smaller hose from vaccume ports go directly to the CAI. The PCV just dumps under the car now. The smaller hose and it going directly to the CAI means 0 unmetered air entering the car, and less air being sucked down at idle.
It has so much vaccume when you let off the gas, the TB blade sticks a little sometimes lol. Sortof annoying, but eh...it revs down quicker now though. No such popping either...my exhaust only makes a very slight pop (like 1 SMALL pop) every once in a blue moon. (true X pipe baby) Popping is a sign of unnequall pressure in the exhaust = less HP. Thus the H vs X debate crap.
It has so much vaccume when you let off the gas, the TB blade sticks a little sometimes lol. Sortof annoying, but eh...it revs down quicker now though. No such popping either...my exhaust only makes a very slight pop (like 1 SMALL pop) every once in a blue moon. (true X pipe baby) Popping is a sign of unnequall pressure in the exhaust = less HP. Thus the H vs X debate crap.
