testing aicv plugs

[gixxerbob]

how do i test the iacv plugs.

ok here is the deal: my 95 s14 w/ s14sr20det would idle just fine but as i decellerated to a stop under no load the engine would go from whatever rpm it was at to bounce off 0 rpm's and stutter back to idle or stall out. i pulled the plugs off of the iacv and drove the car, it idled the same and died the same way.

how can i test the plugs for power/ground or what sould i be looking for before i buy a new aicv?

what part cross references to a s14 sr iacv?

[gixxerbob]

i found pdf page 306 in the fsm but it is still unclear

[schanne]

Just replace the iacv. Sounds to me as its had its last day. Check the sponsers to the right for that. Simple

[el OCHO]

r u running a atmospheric bov?

[gixxerbob]

it still did it when i disconnected the bov

[boro drift]

There are two solenoids in the iacv (aac actually). There should always be 12v going to one of them at all times. This is the solenoid that ''catches" the idle coming down from revs. The other is for idle up when the ac is on. If you remove the aac, you can apply voltage to see if the solenoid is working and to see if it is gummed up.

[lbkidsr20]

<------NOOB...................................anyone have a diagram having the same problem but dont kno what your talking about

[gixxerbob]

a pic i stole from google. http://img441.imageshack.us/my...0.jpg

pg 310 of the fsm says the solenoid controlls the a/c (purple plug)

pg 306 i guess the aac valve controlls the idle (brown plug)correct?

[gixxerbob]

ok, i put a 12v and ground to each plug and they both worked, i guess there is no signal being sent. a bad aac would cause the motor to not catch idle on a de-cell...correct?

[boro drift]

Yes. But so will a boost leak, and incorrect timing.

[gixxerbob]

im boosting to 14 w/ 21-23 vacuume...i think ill check my timing and the power to the plugs 2moro

[gixxerbob]

i ended up taking the harness out of the car today and the black/fellow wire was not connected to the f4 plug...now it is and the car idles at 1600rpms....i cant get it to go lower.

[gixxerbob]

the motor would have a problem idling when cold, but once it warms up it idles at 1600. if i unplugged the brown iacv plug when warm it idles properly at 850.

i replaced the ecu coolant temp sensor but no change...what could cause this high idle, the acv is clean, i have 22lbs vacuume, and the timing is good, and the tps is .5v

[boro drift]

Is your throttle body clean? Make sure its closed all the way.

[gixxerbob]

the throttle body is clean, it closes all the way, the stopper is barely touching it.

i checked the timing again today and it was exact (2nd mark from the right)

i put in a 300zx maf and still have little-no idle when cold and high idle when warm(1400-1800rpms) (seemed like a good excuse to get it done)

the coolant temp is good.....might i have a auto ecu..the nimbers on the ecu sticker is scratched off in just the place where the part# is...

what would a auto ecm cause?

what should happen if i unplug the coolant sensor plug and try to run the car?

if i unplug the iacv and it idles normally (but does not catch idle on decel) this means the ecu is sending a signal to the iacv to idle high...how do i figure where it is comming from?

[gixxerbob]

fyi i have a safc2..i put in the correct sensor in for the z32 maf (2 in 5 out)it is not tuned ( i was going to have it tuned asap but i cant w/o a good idle)

i also have a walbro 255 w/ stock fpr

i will mount my nismo fpr and z32 fpr when i get the adapter and gauge

the car has been running since the swap

i just repaced the pcv valve and still poor idle
Modified by gixxerbob at 6:28 PM 9/22/2008

[boro drift]

Are you absolutley positive you have no boost leaks?

[gixxerbob]

i am sure that my gauge says 23 vacuume at its idle..and it spools to 14 quickly w/o bucking/sputtering/poor performance...

i am sure that the brown plug is the problem on the iacv. When unplugged the car idles as it should...when plugged in it idles low when cold, high when warm...

it is getting signal from somewhere to raise the idle

what should be the ohms reading on the aacn solenoid?

[boro drift]

With the aac unplugged, and it's lock tab up, test the resistance between the top two terminals and the ohms should be 9.6 Thats what I got in the fsm anyway.

[gixxerbob]

with the brown plug facing up, and my Etek meter on the 200 dial setting under ohms i got 9.9

tomorrow i am going to try to switch o2 sensors with my friends black top

how the temp affects the idle is what makes me think it is exhaust or coolant related

[boro drift]

The Walbro fuel pump running through the stock fpr might have something to do with this. Those pumps push more fuel than the old tired fpr can handle alot of times. Get your new fpr on there and see what happens.