DIY FITV clean

So your FITV or Fast Idle Thermo Valve controls idle on OBD1 (possibly OBD0) vehicles. On OBD2a and OBD2B this job was delegated to the IACV. The FITV controls idle via coolant temp and will idle your car higher. So why would you want to clean it?

Reasons to clean:
Idle surge (during warm up)
Idle surge (after cleaning the IACV)
misc idle problems
HELMS says to purchase a new one if it breaks.

Now to the fun stuff, where is it located? Below is a picture of a throttle body with an FITV equipped.

(Edelbrock 65mm)

and below is a throttle body for OBD2 without one.

(Skunk2 Alpha 66mm)

Now, how to clean it:


Step 1:
Remove your intake however you go about doing that. and then disconnect the sensors connected to the throttle body, there are two plugs one on top and one facing the frirewall, the map and the tps. There are two coolant lines you then need to disconnect on on each side of the throttle body. Then unscrew the four 12mm bolts or nuts (depending on what you have) NOTE: Skunk2 throttle bodies have hex head bolts to secure them to the manifold. Remove the throttle body, and keep the gasket clean or buy a new one. you should end up with this


Step 2:
Unscrew the FITV there are 3 10mm bolts on the bottom of the throttle body, unscrew those and be careful when removing the FITV. it looks like this.


Step 3:
Remove the 8mm bolts here and take the cap off

with the cap off:


Step 4
unscrew the white cap with a flat head, be careful its kind of brittle once thats off take out the valve


Use break cleaner to clean it out and a rag to dry it it should look pretty snazzy.


Step 5:
(Optional)
You may clean this dude here
it separates into 3 pieces


Step 6:

Put the valve back in and when you tighten the cap on, snug it and then back it out a quarter of a turn. Your idle should be fine. Then just put everything back where it was.

When you say idle surge during warm up, does that mean it isn't normal for the car to idle 1k above normal during warm up in the AM? both of my regs did this and I always thought it was normal. The first teg was stolen, may she rest in peace.

j13 said:

good DIY for the guys on the older computers

Click to expand...

yes sir. they actually can use the Skunk2 Alpha series tb like i purchased, it will just take longer to warm up.

Ryan659 said:

When you say idle surge during warm up, does that mean it isn't normal for the car to idle 1k above normal during warm up in the AM? both of my regs did this and I always thought it was normal. The first teg was stolen, may she rest in peace.

Click to expand...

No, idle surge is when the idle fluctuates between x rpm and x rpm like it goes up and down, the idle is ALWAYS supposed to high when it starts when cold, but it stays constant and drops slowly.

i remember doing this on my DC2....solved my idle issue.

iv always wondered what was the name of that . now i know awsome

So what about when it's cold? I know it states warm, but lately here in Texas with the "cold" (yeah below 45 is cold) my rpms will go to 2k then drop to 1k and surge back up. Does the FITV still affect it?

p.s. it's an obd1

friday i swapped intakes. i had bought another oem intake and had it cleaned and powder coated. wheni installed it i just took the TB, sensors, and iacv off the old and put it on the new powder coated one. now when i start it it idles at 2000 rpms for about 30 seconds and gradually drops down. i cleaned the iacv and when i started it after cleaning it idled at 900-1000 rpms which is where it idled before. but my new problem is that after i drive it for awhile and put it in park or neutral it constantly jumps from 1000-1500 rpms. should i clean the fitv to see if that clears it up? pissed and confussed!

i checked for leaks in the intake and found none. i checked all my hoses for vaccume leaks and all wire connections. all was good.

Nice job D !!! :thumbs up

*You don't have to remove the Throttle-body to do this. As you can see, there are only three bolts.
Estimated time for this project; 30min to an hour.
Tip - When screwing the white cap back on, use your fingers and push down a bit, much faster than using the screwdriver.
- Aaron

Dope write up, thanks for the help good sir!

Dylan dropping that great knowledge!!