MSefi.com read only forum (Jan.15,2018)

UPDATE: I found a loose ground fixed that up, same issue. I tried putting the ignition advance to fixed timing from use table, revs to the sky no missfires or anything. What would this indicate? Could my trigger offset be incorrect? if so can someone guide me through the steps incase I did it ...

I'm also seeing noise on the battery voltage that is affecting fueling. Where's it grounded?

Where is what grounded? The battery goes straight up front to engine block. From there it goes to the sway bar mount. Everything in the engine harness is just factory I did not ground anything different ...

The only place I'm seeing noise is on the CLT signal. However, that's noisy enough to be adding up to 50% more fueling at times, which could account for the stumble. I would check your coolant sensor wiring.

Got the coolant sensor squared away. Still have the exact same problem though. I noticed ...

This is my thread over on the corral if it helps. http://forums.corral.net/forums/megasqu ... issue.html

Here is a datalog and the tune file. On the datalog where the af goes flat I was just using the playback on the wideband monitor. A few other people have told me this could be a noise issue? The wideband does go rich but nothing to crazy. Any help would be great. Thanks.

Quick rundown of the car:

MS v3.57
89 mustang
83lb injectors High imp
h/c/i
347
blower
digital 6, blaster, firecore wires, good tested dist.
SD

The firing order is the NON HO order which is, 15426378.

Plugs are looking pretty bad now but I am guessing it is just from all the missing. New plug ...