Afr's randomly drop 3 points while driving
#1
Afr's randomly drop 3 points while driving
I have a 91 turbo miata running ms2 and innovate mtx-l and recently the car will randomly drop 3 points on afr gauge and stay there for a while around like 11.1 cruising. Sometimes the car will be normal, 14.7 cruise and 12 under boost. Almost like the car has two different modes? I changed the wideband sensor thinking it went bad and it changed nothing only other thing I can think of is the wideband itself or maybe a wiring issue with wideband itself. Car ran great before this and any help greatly appreciated - Brady
#3
Elite Member
iTrader: (2)
Join Date: Jun 2009
Location: Istanbul, Turkey
Posts: 3,214
Total Cats: 1,687
Tune and log like Curly said, AND check the vacuum line going through the firewall into the MS.
DO NOT assume it is OK just by looking at the thing.
Start the car and wiggle the vacuum line while keeping an eye on the AFR / Vacuum gauge.
If you do not have those gauges, hook up your laptop. TS will have them on your screen.
Also, pull up your VE table and look at it in 3D mode to make sure you don't have unintended peaks and valleys.
Some laptops have very sensitive touch pads and that has the potential to create unpleasant surprises on tables and whatnot.
DO NOT assume it is OK just by looking at the thing.
Start the car and wiggle the vacuum line while keeping an eye on the AFR / Vacuum gauge.
If you do not have those gauges, hook up your laptop. TS will have them on your screen.
Also, pull up your VE table and look at it in 3D mode to make sure you don't have unintended peaks and valleys.
Some laptops have very sensitive touch pads and that has the potential to create unpleasant surprises on tables and whatnot.
#6
Ill try to post log tomorrow, in middle of moving so no internet but heres info on car, no vtps https://www.miataturbo.net/build-thr...-thread-93517/
#11
Cpt. Slow
iTrader: (25)
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,224
Total Cats: 1,145
No the one on the thermostat neck is for the 1.6 fan. The single wire on the back of the head is for the gauge cluster, and the 2 wire with a green plug is the ECU sensor. Randomly dropping out like that, I’d expect a bad wiring connection, not a bad sensor.
Thread
Thread Starter
Forum
Replies
Last Post