silvertn350

OK so I have a megasquirt 1 version 3 that was made and installed by a member on this forum. I keep having this glitch of some sort and my car bucks when this happens while driving. It does it randomly and I can not figure out what is triggering it. I'll be driving at WOT and then randomly it will miss and go crazy for a second then be ok. It is currently tuned map-based because we could not get the TPS to work properly. It is indeed working well now and I am waiting untill I figure this issue out before I get it re-tuned TPS based for more boost.
Setup :
95 1.8 with a turbo setup, dsm 450's with acura resistor box and modded flyback circuit. Toyota COP's.
The following is wired directly to the MS bypassing the factory harness completely:
TPS, Coolant temp, intake temp, & the CAS
the only things still on the factory wiring are the injectors and the coil packs.

Any advice, questions or concerns are welcome and appreciated:


more pics of the datalog are available if need for further analysis.

lordrigamus

iTrader: (14)

Are all your grounds clean, tight and all where they're supposed to be? does it have a solid power supply?

silvertn350

all 6 grounds from the megasquirt are going to the same point on the chasis. I sanded off the paint and made sure they were clean. Its getting its power from the white/red wire I used this diagram:


All of the grounds in the engine bay seem to be in order. I even supplied an extra from the engine to the chasis. I've been contemplating on adding a few grounds to see if it would clear up the issue.
Maybe something like this:
chasis point that the megasquirt is using to the engine itself
maybe one from the negative of the battery to that same point?

CAS is getting its own ground from the valve cover. Shielded wiring was used from the CAS straight to the MS and the copper inside is getting its ground from the same grounding point on the valve cover. TPS is getting its own ground from the OE grounding point at the front next to the throttle body. Coolant temp is getting its ground from the valve cover as well.

Matt Cramer

Looks like a communications glitch, but if you could post the whole log I will be more certain.

Latch

iTrader: (1)

Both your MAT and your MAP spiked up, what's weird.

StarGehzer

Check the connector & harness that the sensors are connected to. It looks like everything was unplugged then there are a couple of spots where a wiggle briefly made a reconnection.