Nissan ECU Tuning

StinkyZ · Joined: 10 Dec 2003 Posts: 111 Location: Tampa, Fl

Ok here is the situation. I've got a z31 with TT injectors. The ecu is very similiar to the z32 ecu so just about anything will apply to both. I'm having some issues with my high idle when the air conditioning comes on and both my electric fans are on. First let me explain how I tuned my K and void just to make sure I have it right.

I tried using the same K as the TT bin file and it just so happened that it seems about right. What I did to check this is set the entire fuel map to open loop 12.5 afr and log a couple trips around the block. Most of the afrs were pretty close to 12.5 so that means my K is pretty close to where it needs to be.

Next I needed to adjust the injector void because my idle afr and low load/rpm afrs were a bit higher than 12.5. So now I have the void adjusted to about 58h and they seem to be about where they need to be.

Ok so now my afrs read pretty much like the fuel map (12.5 all the time). I put the fuel map back to stock with closed loop. No problems.

Now whenever I turn the ac on at idle and the load on the engine increases the engine will stumble and usually die. My wideband shows its because the afr skyrockets and there isnt enough gas. When I have the fuel map set to 12.5 it doesnt happen and when I set the ttp min higher it doesnt happen as much. My problem is that if i do either of those two my idle under light load ends up rich.

So to my question. What do I need to do to stabalize my high load idle without screwing up my low load idle? Is there a ttp min for high idle or something similar i dont know about? Does the rest of my tuning process sound right?