denmah

iTrader: (2)

my friend has a 08 G8 GT, and we installed some juice on it the other day, some random parts laying around, edlebrock bottle, dynotune and NOS solenoids, dynotune nozzle and NOS jets.

we are using a micro switch on the accel pedal, and a MSD electronic window switch.

the tach signal is tapped into the purple wire in the drivers side coil pack harness, i read online going thru google searches to find that was a good source. Well it works great. accept for the simple fact that when the window switch is plugged into it, reguardless of wether or not the window switch is turned on or off, it throws the p0351 code, for missfire in cyl1

this is extremely annoying and obviously makes the cyl dead. causing pops in the exhaust while all the unburnt fuel and nitrous hits the hot as hell catalytic converters...

does anyone else use a different source for rpm? i know on LS1s i have read you can use the white wire out of the ECU, that goes to the dash for the tach signal.

at this point me and my friend think its the MSD box grounding out the coilpack or something similar. because we have run these boxes on many other cars and not had trouble.

any help would be appreciated, here are some pics of the install, well while it was being installed.

wot switch


arming switch


nozzle


fuel noid attached to the rail


msd window switch


nitrous noid


car went 12.55 @ 100mph on the brakes after the backfire at the 900ft mark lol, on a 2.0 60ft.

currently jetted at 150, we would like to step up to a 175, but not if a cyl will be dead.

thanks for any help guys!

denmah

iTrader: (2)

anyone know the tach signal wire on the pcm? for a g8?

Nick@HSW

iTrader: (4)

You can pull it off of the coil pack itself, but you will need a window switch that can interpret the signal (IE run in single cylinder mode). What color wire do you have running to the coil pack now? What color wires are in the wire harness you're trying to tap into?

Nick

denmah

iTrader: (2)

we used the purple wire on the drivers side coilpack harness.

it is the trigger for cyl1

it reads fine it just throws that missfire code in the car.

Bad Habit Bird

iTrader: (12)

Just a thought. You might want to take that 90 degree fitting off of the fuel solenoid and run a straight fitting instead.

denmah

iTrader: (2)

thanks, it seems to work well there, but noted.

any answers on the tach signal?

Robert56

iTrader: (2)

Is it the odd wire out? That means, each coil pack has four wires, each will have three of the same color, you want to attach to the "Odd Wire" color. Just something to check before moving elsewhere. But like Nick said, it's likely a MSD issue not a pick up issue. I know my past MSD controllers only worked in 4-cylinder mode on the Lsx platform. But this spot needs single mode.
Robert

denmah

iTrader: (2)

yes, its definately the odd trigger wire.

and it reads correct rpm in 1 cyl mode.

denmah

iTrader: (2)

my friend is picking up a new MSD window switch, so we will find out if the brand new one does the same thing, we will have to hunt down the PCM tach singal wire out of the ECU.

anyone have a pinout, the dudes on G8 forums are too busy thinking about 22inch wheels to buy

ArklaTexan

iTrader: (24)

this is way old obviously but the solution to this problem is once you wire it up you must disconnect the battery for 5 minutes or so. Then the check code does not come up. I had the same issue when I was installing a RPM switch. Found this solution on g8board.