shooterschmidty

Hey guys,
I just upgraded to a MapDaddy MAP sensor in my DIYPnP and am having some problems I'm hoping you can help me with. Before the install the car ran fine on the "standard" MAP sensor but now after the install, starting is very difficult and it's sitting at 10:1 AFR. I desoldered the old unit, soldered in the MapDaddy and took the additional input to the Baro/ADC2/JS5. I selected the MPXH6400 as the sensor in the "Sensor Calibration" pull down and made sure that the cal values are the same as on the diyautotune website. Baro correction is set for two independent sensors and I've tried both "SPAREADC2" and "REMOTEADC2" as the realtime baro port. When I start the car the engine MAP guage in Tuner Studio reads vacuum so I think the unit is working but obviously something isn't right. Just to make sure its not something else, I reinstalled the old MAP sensor with the appropriate settings and the car fired right up. Any ideas?

shooterschmidty

It actually sounds like it's not firing on all cylinders. The plug wires look good but I'll have to wait for a friend to help me check if I have spark. However, it seems unlikely that this is a coincidence unrelated to the installation of the new MAP sensor. I'd guess that I messed up something else on the MS board if it didn't run fine with the origional map sensor when I swapped it back in.

Braineack

iTrader: (62)

what is the MAP reading (of both sensors) with the motor not running?

shooterschmidty

Thanks for the reply Brain. When I first hooked up my laptop without starting the car both sensors read ~84 kPa. I then started the car and idling at ~10:1 the baro read 79.2 kPa and the MAP read 43 kPa. I then turned the car back off and the MAP returned to 84 kPa but the baro only came back to 77.0 kPa. During this period the ambient atmospheric pressure in Denver was 101 kPa as reported by NOAA and wunderground. This seems suspect to me as thats the standard pressure at sea level and the standard atmosphere table calls for a pressure of ~84kPa (didn't bother to interpolate) at 5000 ft. If the 7 kPa differential exists while the car is running that'd be a 8.3% error. Enough to cause me to run that rich? Hysteresis in my baro sensor?

shooterschmidty

Upgrading to the latest firmware and tweaking my idle cells solved my problem.