eiblanco

This is my first post to this forum, I apologize in advance if I don't provide information that is necessary to help diagnose my problem. Background- I have a 2001 miata with a FMII turbo system that was installed by a company here in Colorado Springs called Under Pressure Performance. The engine internals are stock- its running a Garrett 2560R turbo with the FM intercooler and a Megasquirt 3 PNP. It has a new water pump, an FM cross flow radiator, and a supermiata re-route. It has a AEM wide band and the GM IAT. It was tuned on a dyno. The alternator is producing 13.5 volts running. At a cold start the AFM is in the low 12s at idle, at running temperature it creeps up the low mid 15s. When I first received the car from UPP they had the IAT at the air box, and the new IAT where FM suggest it should be installed near the throttle body was not wired. I thought this was the original problem. I took it back to them, and they wired it to the correct location- but it still is displaying the same problems, stalling at stop lights- running rough, poor idle at running temperature. The fans do not stop running when warm, but the temperature gauge remains normal at midline. What questions should I ask them, and what could be causing the problem? People on the facebook page have recommended opening tuner studio and making one of the gauges for gamma enrichment. You'll be able to see what your overall fuel modifiers percentage is as the car warms up. Bottom line everyone says take it back to Under Pressure Performance and that its most likely a problem with the tune. I just want to make sure I ask the right questions...

Cold start normal AFM

Voltage running measured at cigarette lighter

AFM at idle at running temperature

Original picture with IAT not wired

Watterson02

AFM stands for Airflow meter, which was how the stock ECU measured airflow. I think you meant AFR or air-to-fuel ratio.

A 15.4:1 warm idle isn't too bad. The richer cold idle could be explained by Warm-up enrichment. Are you sure the car wasn't tuned this way?

curly

iTrader: (25)

Did you pay for a full tune or a dyno tune? Full tune should include cold start, hot start, drivability, throttle response, etc. Dyno tune will set boost level and power/safety at full throttle. Both are necessary IMO, but not always purchased. It's possible they're not familiar enough with Megasquirt to solve some of the problems, but all I see is that your car needs some fine tuning. Dying at a stop is most likely your initial value table, cold AFRs in the 12s is normal, and warm AFRs in the 15s is either tuned that way or needs some EGO correction.

You've got a Megasquirt, so if you'd like some help you're in the right place. But you'll need to post your current tune and a datalog of the issue happening before we're truly able to help you.