rb20 running like crap at cold start, closed loop.

[b00stinbmx]

yup so i searched around and pretty much came up with a few things. first i tried wiring in my orange pin 43 start signal it helped but that wasn;t all my problem. basically when you first start the car you have to keep the pedal to the floor and it just barely wants to catch... eventually it will and the revs smooth out and it will idle good, but if you try to drive it at all it just sounds like its misfiring and won;t even rev up that high. as soon as its warm the thing runs like a champ, absolutely perfect. at first when i did the swap i dealt with it but now this is getting kinda annoying.

anyway after some searching i've come up with a few things but im not totally sure i fully understand. im figuing its prob my o2 sensor correct? im nto sure if its just the heater wire thats not hooked up, or if the sensor is shot. i am going to wire in a consult port soon to my s13 so i can figure out whats going on if im throwing any codes becuase my rb ecu has only the selector screw no LED. anyway lmk if you guys got any suggestions. thanks!

[dtowngoalie]

checked your timing?

[b00stinbmx]

yes timing is set to 15

[onepuff]

How does it run after around 3000 RPM? Does it go back to normal around 150F? There is an issue with RB20's with the warmup timing. There is a part of the code that pulls timing back to 7 BTC. I had/have a similar thing. I spoke with Matt from Nistune and he found the part of the map that controls this and it can be adjusted in the Nistune software.

[onepuff]

Here's a screencap of the warmup timing settings in Nistune.

[b00stinbmx]

yup that pretty much sums it up. well i guess i'll have to get nistune hooked up on my car soon if thats gonna be my only hope if fixing it. was going to be running nistune soon anyway so at least i know i can deal with it when it comes time. but yes if u rev over 3000rpm it clears up and once it is warm like u said around 150+ it clears up

[lexrob]

That sounds like a legit solution. I just wanted to add something some ecu's are set up with a stepped ect sensor circuit. In other words at 120-150 F it may switch to a bigger resistor at that point to remain accurate.

Just readin out of a book i had for school. ??

[lexrob]

wow nistune looks user friendly! sorry to jump on ur post but can you dattalog with multiple sensors and wideband "easily" and edit in real time... ill look into it im still newb to nissan

[onepuff]

Nistune is a really great solution for Nissan tuning and the creator is very helpful and always trying to improve on it. Not sure what all sensors you mean but it u can datalog all the sensors that are seen by the ECU basically and u can also get an input from quite a few different wideband sensors. There is a pretty active forum for Nistune also. Here's a cpl links.

http://www.nistune.com/

http://forum.nistune.com/