I have a 93 with M2 mods: intercooler, intake, exhaust, big fuel pump, and their stage 3 ECU upgrade. The: car was set up for sea level and I'm living at 4400 ft in Western Colorado , so the car is running rich. M2 is out of business, so i can't call them. Any thoughts would be appreciated.

Thanks,

John

 

Exactly what makes you think you are running rich?

I don't see anything in your mods list that suggest you can monitor A/F ratios (unless you didn't list it).

 

A group of us are having a tuner come out sometime in May, perhaps you want to take a short trip to the Denver area! Of course we are at 5200 but who's counting....

 

Last time I checked, you can't tune an M2 ecu.

 

Strike that last one from the record then I guess!

 

My Mazda tech says it's running rich and it backfires between full throttle shifts.

 

That can be caused by other issues with the car (i.e. worn/old plugs, TPS adjustment, etc) and some amount of backfires between shifts can be normal depending on the mods of the car. First, you need to go through the normal maintenance routine:

1. Check spark plugs/wires
2. If on the stock or rechipped ECU, check the O2 sensor
3. Check to make sure your ground wire are making good connections
4. Check the TPS calibration

If your mechanic doesn't know how to check these things or hasn't done it, find a new mechanic.

 

Thanks Mahjik!