Load jumping around

Hey guys,

i was trying to tune an SN95 mustang with an AMPEFI pnp MS3 and am having wierd problems (Doing tuning remotely so dont have access to the car directly)

The engine Load seems to jump randomly while driving. its most prevelant when under acceleration and closer to 100 KPA but also happens at idle (normal idle at about 35 KPA and jumps to 60 on the load axis (MAP sensor value does NOT change though.

Any idea what this could be? Battery voltage seems stable but a bit high for my liking (15.3-15.8v) car is running speed density.

Where does the Load channel come from? Is it a MAF sensor (if so, the units should not be pressure, but air mass)? If Load is a calculated Air Density (MAP corrected by Air Temp), what is the Air Temp doing?

What's up with your fuel pressure? Is that wired / calibrated correctly?

Im using the MS3Pro pnp standalone ecu im using map no maf and my fuel pressure should be 58psu but when I set it I unplugged the vacuum line and moved the screw on top of the regulator till it got to 58psi

Your picture of the data shows fuel pressure goes from .1 - .7 bar (about 10psi). And it drops to zero when at full throttle. So something's not right.

So should I try and put it to 43.5 psi and change the. Dead times and pulse withs?

I would try to understand why your fuel pressure sensor is reading 10 psi instead of 58psi. Perhaps it's not configured correctly, or maybe there is a wiring problem, or maybe the sensor is bad. Or you are measuring the pressure in the return line to the tank. All I can tell from the picture is that it is not what you would expect to see.

I have not suggested changing fuel pressure or deadtimes, unless you know that what you are currently using is not correct.

We can only guess at what might not be correct. In order to provide more help, I would suggest that you upload a tune file (.msq type), and a log file (.csv I believe). If you can't attached that here, then put it in a zipped folder / archive and attach that.

Yes my fuel pressure regulator is after the fuel rails to the return. I dont have a pressure sensor on my 98 cobra. This is how I have it set up

I don't see a fuel pressure sensor in your diagram.

I don't have a fuel sensor my year of cobra dosen't come with one only the evap Canister