4A-GZE (AW-11) Problem

[Puss-on-Boost]

Ok well this is abit of tale so here goes!

My friend has an AW-11 Aussie with a GZE (AFM type) conversion...everything has gone well until a recent engine rebuild which when up and running again has some hunting issues.

Basically sometimes it will idle around 2500rpm....then sometimes it will hunt between 1000-1500rpm. randomly the check engine light would come up aswell. Also when you lift off the throttle the motor would take extra time before it would return to idle and increase revs if you changed gears around 2000rpm. Diagnostics didn't bring up anything.

So today we had a closer look at it and after unplugging the TPS the hunting issues stopped but the overrun was still there....after some more prodding about and unplugging a larger idle motor (hosed from just infront of the TB) the over run problems were gone aswell and the car behaves as normal...drives extremely well!!

The next thing is the check engine light doesn't always come up even with the TPS and idle motor disconnected! we drove around for a good hour with some shut downs etc and the light sometimes wouldn't come on at all but sometimes would come on after different amounts of time. one thing we noticed was the light almost always would come up while going uphill

Has anyone ecountered anything like this before??

Any help would be much appreciated.

Cheers
Ben

[MR22ZZ]

How much petrol is in the tank? And is it possible that the Fuel Light and the Check engine light are mis-wired

[BeRad]

Is the idle speed motor connected into the intake piping? if its not or its blocked off it will cause it to hunt and/or stall, the afm wouldnt have compensated for that air which would cause hunting.

But the hunting around could be the idle speed motor not working the way it should, it mightnt be closing when the tb is opened and that would cause the engine to maintain its revs for a little bit when you back off, or the car is really lean, is the afm plugged in properly???

Is the throttle body seizing up (tight to turn by hand or with the cable), has the throttle cable got a crack in the casing which would stop the butterfly from returning to closed straight away when you back off.

when the engine came out for a rebuild did any wiring get messed up? haha may sound stupid but could the signal wires for tps and idle speed motor be switched around.

[Puss-on-Boost]

full tank, lights were not touched while motor was rebuilt.

yea the motor is connected to the intake piping.....when i pulled the hose off it improved the overrun......the hunting stopped when the tps was unplugged as i said above.

[Adsport]

sounds like a dodgey idle valve maybe its sticking or theres some crap in there or an air pocket where the coolant goes through causing bad readings in the sensor.