New TN User
Join Date: Aug 2013
Location: South Australia
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
1AZ to 2AZ conversion = lean engine problem
I recently fitted a 2AZ engine from a 2010 Camry into a 2002 Avensis Verso which had a 1AZ engine in it. This model Avensis has 1AZ/2AZ on the sticker in the engine bay so I'm guessing it came out with 2 engine options. The 2AZ engine retained its injectors and coil packs but apart from that everything else is 1AZ, like water temp sensor, MAF sensor, 4 x o2 sensor exhaust manifold, knock sensor, ECU, throttle body, etc. I'm getting a knock sensor code on my OBD scanner and have reset it about 10 times, but it still comes up. Also replaced the 2 x 02 sensors after the cat as they both had failed heater elements. Only thing is I used the original ones that were on the Camry engine (1 being a before cat sensor and the other after cat sensor). I'm not getting any other code except knock sensor issue. I could hear the engine ping under load so I pulled the spark plugs out and they indicate an extremely lean burn, and these plugs were used and had a small amount of black soot on them when in the Camry. I have no vacuum leaks, all gaskets seem fine, replaced a perished hose from the rocker cover breather. What could be causing such a lean fuel mixture? The maf was fine on the 1AZ so I don't think it's the maf, only thing I can find that's a bit sus is that the 2 pre cat 02 sensors have a 4 ohm reading across the heater element instead of the recommended 16 ohm which seems to cause the voltage to drop down to around 4Volts when ignition is on and back to 12.8V when you unplug the 02 sensor - no load, all these sensors were fine on the 1AZ. Could it have a different maf for the 2AZ, the Camry I bought as a donor for the engine had a small fire near the maf and it was destroyed. Sorry for the long post but I wanted to make sure I included everything I could think of. Thanks in advance guys.
Last edited by R100; 08-02-2013 at 08:58 AM.
Reason: Attached a pic of the plug