Thread: Iac Valve

I doubt the engine will work at all without the IAC valve, it is connected, via the small air line to the Fuel Pressure Regulator. The cone shaped valve should be movable on the spring behind it, the cone piece needs to be free of carbon as does the seat that it seals in, make sure that neither of the 2 rubber air lines has a leak and make sure the valve body seals against it's gasket and is tight, Regards Frank.

No the IAC plate is just a convenient place to have the nipple for the Fuel Pressure reg. It has no connection to the IAC.

By clamping off the inlet hose you are just reverting to base idle, which is set by turning the little grub screw above the throttle plate. The base idle should be about 550 -600 RPM with timing checked and throttle plate and surrounds clean. You should disconnect the IAC hose at each end then cover the ends with duct tape or similar to ensure no leakage.

Then you should clean the IAC "cone" and the bore it runs in with carby cleaner . Do not maniipulate the IAC as you can damage it. It will reset itself on startup.
Regards Philip A

thanks , i work for nissan and on some of the older nissan cars the iac does a sweep thru its range dependant on its design upon turning to ON with the keys before returning to where it was.. was just trying to sus out how these back the front landrover systems work :P ,also in my first post i did not mean engine on i ment ignition on... gee seem to be getting a bit dislexic , the engine definately wont work without the iac installed as there would be such an air leak past the afm.

Yes it does a sweep when the ignition is turned on.
It is the same IAC as fitted to numerous GM cars and probably Nissan.
Regards Philip A

thankyou very much phil , i thought that should be the case however even after cleaning mine is still jammed up , as a stop gap measure i have adjusted the needle part by unscrewing it slightly so it stays in a preset position of about 750-800 rpm idle warm , not a perminant fixture however enough to get me out of trouble at present.. and when put into gear (auto) or ac on or both still reasonable idle and no stalling.. will have to get another valve in due time however at present there is no driveability concerns with it setup how it is except my annoyance being a tradie mechanic and noticing the high idle all the time when no load is placed on the engine.

OK just for you (really for me) I have done a LOT of research on cross refence part numbers, mainly from the US. You should be able to get one cheap on ebay or just google the number.
GM 25527077
NAPA 2-1738
AC 17085051
AC 17086051
delco 73312A
Lucas WO133-1607744
Rover ETC 8494
Regards Philip A

thankyou , this has to be the most helpful forum i have come across..

BTW , all care and no responsibilty. You should confirm these before you order. I did it some time ago, but also refer to Range Rovers Net which has a big segment on the subject. AFAIR some of the numbers on there didn't google but some did.

Regards Philip A