Link Cold Start Tuning: (Jeremy @ Flyin Miata)



Wanted to pass on some info for those having cold start issues with their Link. These are things I am putting in the tuning manual, which I am revising.. The following is the order in which to set this up for your car. This takes time and many cold starts. This tuning will be most accurate with Lambda and L3 turned OFF, however if you are way off base you may have to start with them on, then after making adjustments do a final series of dial ins with them off. Remember to always keep Lambda and L3 on for everyday driving.

Make sure that when fully warmed up, your fuel maps are tuned correctly and smooth. When this is the case, your L3 compensation will be always in the 4-6 range. (this number is the 1-9 in the RPM screen that moves around when L3 is on) 5 is no compensation. Greater than 5 is adding fuel, less than is removing fuel in order to meet your O2 targets (z26-z31) Most importantly for cold start, make sure that your zf100 (idle) is spot on stoich. Since your zf200 and 300 wil basically not autotune, you can make them manually a point or two higher than zf100.

Once that is set, you can address cold and hot restart. Lets look at hot first. Any time you start the car when the water temps are over 80, look in the O2 reading screen. The value in hot restart is additional fuel that will decay over the first 90 seconds or so. Adjust your hot value such that your O2 reading gives an a/f ratio in the high 13's/ low 14's when at idle, ad decays out to stoich as the fuel goes away.

Cold is trickier, because Cstart T and F are stacked on top of it when you start the car. For now set Cstart T to 4 so it goes away quick, I will address that later. When you start the car and the water temps are below 40-ish, once again look at the O2 screen. Wait a few seconds for that Cstart fuel to go away and the RPM's to come down. Then, while idling, adjust your cold value such that your a/f ratio is in the high 13's/ low 14's, and decays smoothly to stoich as the water temps rise up towards 80. As it is warming up through the 40-60 range is the best time to dial this in.

Cstart F is the choke fuel added to the top of cold to get the car going. Cstart T is the time it takes for that fuel to decay. Once all above parameters are set, make Cstart F equal to just enough to keep the car from stalling right after it has started. Make Cstart T just long enough that you don't get any stumbles under acceleration when first driving the car.

Cstart F, and possibly injector prime, will need to be adjusted with large changes in the ambient temperature. (i.e. summer -> winter)

The last thing is Injector Prime, z715. This is the key on fuel squirt. Adjust it such that the car fires on the first crank. If you find that this wants to be a different value when the car is warm than when the car is cold, make a compromise and let me know. Working on that one.

If the car fires then stalls when cold, your cstart f (and maybe cold if it is not dialed in) needs to be adjusted. If the car cranks for a while before starting, your prime needs to be adjusted. This adjustment can be up or down, remember too much fuel is as bad as too little here.

Anyone who sets this up well can share the values with me, it helps us to decide on defaults that are the most useable for the most people. Feel free to email them to me at jeremy@flyinmiata.com