Alright Im having a problem with a friends car and need some input.

Car is a 2000 LX d16y7 and we converted it to manual over the weekend.

The motor was pulled for the conversion (and to replace the mounts). Prior to the motor being pulled everything ran fine.

Were still using the obd2b auto y7 ecu
i jumped the 3 wires together for the conversion

with the IACV plugged in upon start up the car was idling at 2k. Then it started doing the IACV rev 1500-2000 up and down with a/c off. When the a/c was turned on we were getting a decent idle for a few mins then it started revving up and down again.

With the IACV unplugged upon start up it idles up and down from 1500-1600 rapidly with the a/c turned off. When the a/c is turned on it idles from 1500-1600 but not as rapidly.

I checked the codes, and they are only for the secondary 02 sensor 65 (eliminated) and the trans malfunction code 70.

Also at one point the a/c was kicking on and off which kept screwing the idle up back and forth.

Were going to check for vacuum leaks, but what method would be best to do so?

also what else would cause these kind of idle problems? do we have to use the manual obd2b y7 ecu, and if so we have to convert the iacv to a 2 plug which means we have to find a manual y7 iacv.

any input would be grateful.

 

Sounds like a vacuum leak. One at a time, unplug each vacuum hose attached to the IM and cover the IM nozzle with your finger to see whether the surging/high idle is fixed. Also check for a disconnected vacuum hose.

Bleed the cooling system.

 

jumped what 3 wires together? i hope your using a y7 3 wire iacv? if so sounds liek a vacuum leak

 

the 3 wires are for the auto to manual conversion (makes it think its in park and you can remove the key as well as start up)

and yes i still have the 3 wire IACV with the auto ecu.

 

all y7's even manuals have 3 wire iacv. so changing the ecu wont make a difference. i would check for vacuum leaks. spray form starter fluid or carb cleaner around the intake manifold and see if the idle rises. then you can find out where its coming from. if not maybe turn ur idle screw in alil and see if it can bring it down some and stabilize it's self

 

The idle screw did nothing. We unplugged the map, tps, and IACV and the car was idling perfect at 1k... anyone have any clue on why this would happen?

also we checked for leaks and found one hose going to the charcoal canister that made the idle stabilize at 1500rpms. we need to replace that hose and check for more leaks i guess.