IACV Compatabilities?

[CAFROG]

My idle has been too high lately. It sits around 950 when its nice and warm. It hunts after its been rev'd or put on a load. It only hunts to find the idle a few times and settles down (at 950). Check and cleaned the IACV about 8 months ago so I am thinking its not just a cleaning needed. I have been troubleshooting in my Helm Manual and have a few things I am going to check (including the FITV).

If I adjust the idle speed screw (righty tighty)....I can get the idle lower and the hunting stops....but after a few drives...it goes right back to a high idle that hunts when its warm....this all says IACV to me and my research but maybe you guys have alternative diagnoses?

Can anyone educate me on the compatibility between IACV's off different motors? (plan on hitting up the recycler for a used one) I know the Del Sol VTEC and GSR (both OBD1...thats all I looked at so far) they have different part numbers so that means they are different (at least from what I know about Honda Part numbers)

Anyone know more about this???

Could be my FITV.....doubt it though. Gonna check the hole for it on the TB later. If it is....its much cheaper brand new from Honda.

EDIT: OBD2 is different part number for both Del Sol and GSR DOHC VTEC....so thats 4 different part numbers for their IACV'S

 

[eg6sir]

there is 2 different bolt patterns.. a close pattern and a far pattern.. cant remember what the usdm p30 has.. i'm thinking is the far pattern

 

[FLounder]

yeah what he said...

it seems that older stuff uses the close bolt pattern and newer stuff uses the wide one. d series and b series ones seem to be interchangeable. i wish i knew the specifics on what exact engines and years the different ones come with... but im not sure.

 

[CAFROG]

Now that eg6sir says that.....I remember reading that some where too.

Just wondering if the internal function of them are the same (obviously with the same bolt pattern)

I think they work like hot/cold showers now. Newer showers have a regulator that dictates the flow of cold and hot with a wax ring. If the water is too hot.....the ring swells and doesn't let as much hot water through the line when someone flushes the toilet (thank you "This Old House")

Not sure about the IACV but the FITV is like this.

 

[99sidude]

The iacv gets an input from the ecu, and electronic load detector. It increases idle to spin the alternator faster during high current draw situations.

You should remove the back plate off of the fitv and make sure the valve is threaded in all the way. Over time, the valve will unthread itself from its housing. If it comes all the way out, your car will run like crap once the engine is warmed up. This has happened to me on 2 occasions.

Not to threadjack, but while we are on topic, I was wondering how cold start idle is controlled on obd2 cars? For obd2 it is my assumption that the iacv controls both cold start idle and electronic load idle.

 

[CAFROG]

From the info I have gathered.....OBD2 got rid of the FITV and the ECU became the sol controller of the cold idle.

I have taken off the IACV but you are taking about a plate? Can you explain a little more? How do you get this plate off?

 

[CAFROG]

So I took the IACV off this morning. I took the 'plate' off that houses the coolant nipples and there was nothing inside. Its like a crevice that simply heats up from the coolant line. There is also a Pentagon (not hexagon) shaped screw on the outside of the IACV that I had nothing to get it off with so I just re-installed it

Took Intake pipe off and started it up. Got it up to running temp (radiator cap off to triple check for an air bubble). Anyways, it got to running temp and I checked the access hole in the throttle body for suction. I still have suction and it makes the hunting idle stop when I plug the hole so I figure its the FITV. Although it is idiling high (950rpm) Not sure if its the rubber rings leaking or if the valve is bad. Cool thing is the FITV is 1/3 the price of a IACV for my motor. I have a friend with a teggy with a blown head gasket but can't remember if its OBD1 or OBD2 (no FITV). Would love to try another one before I purchase something (that may not fix it)

 

[CAFROG]

The iacv gets an input from the ecu, and electronic load detector. It increases idle to spin the alternator faster during high current draw situations.

You should remove the back plate off of the fitv and make sure the valve is threaded in all the way. Over time, the valve will unthread itself from its housing. If it comes all the way out, your car will run like crap once the engine is warmed up.

I mis-read the first time. I effed up and read IACV when you were talking about the FITV. It was fine when I put the B16A3 IM in the spring time. I think I will just get a whole new one with gaskets and everything.

 

[CAFROG]

Got a new FITV and it seems to be idling much better now......we'll see

 

[eg6sir]

make sure you dont smash the gaskets by tightening it down too much.. i've done that and had me confused why i had a surging idle for the longest time.. lol

 

[CAFROG]

Yeah......I tried to be easy with the tightening. That metal on the TB and FITV are pretty soft.
And I have snapped a few Honda bolts in my time so I have learned to be more respectful lol

 

[99sidude]

Glad you figured it out