Forcefed86

iTrader: (4)

Trying to plan ahead a bit. I'll be running an AEM EMS PNP setup on my LS motor. The AEM instructions tell me to verify timing with a light and sync the timing on the light to the AEM. Is this even possible on an LSX motor?

I thought base timing was a set it and forget it kind of thing on these new engines?

Thanks

wildcamaro

iTrader: (15)

Yea I don't think its possible since timing is controlled by PCM...

soundengineer

iTrader: (16)

you can double check to make sure it is doing what you command it to....

all lights use an inductive pickup....typically right off of your #1 spark plug wire

you will need to know where TDC is on your crank, and have a mark you can follow
you will also need to know how to set up your device to command a Static timing value...our ls EFI devices control idle with spark timing so you cant just let it idle with no spark control, it will be jumping around all over the place.

you also need to be able to rev it up to make sure its not changing as rpm increases...
if you set it to a static 25* it should stay at 25* no matter what rpm you are at.

Forcefed86

iTrader: (4)

The engine is together so I suppose my only option is to give it my best guess as to the the exact TDC. Then mark the crank pulley and timing case. I'll give that a go and just make sure the AEM is following my inputs.

thanks.

soundengineer

iTrader: (16)

buy a Piston Stop TDC finder.... cheap, easy to use...
screw it into the #1 spark plug hole.
turn motor slowly over till it hits it....make a mark
turn the other direction till it hits, make a mark
the middle is TDC

thing basically looks like this... this on is from summit racing...
there are lots of different varieties of the same thing from multiple vendors


then you will also need to make soem timing marks...
you wont be looking for a flash of light at 0* TDC... you are going to be looking for a light before TDC....

Forcefed86

iTrader: (4)

I think I can tell within a 1/4 of a degree or so when the piston is at its farthest travel. I just hold my finger over the spark plug hole and crank the engine to find out when it's on the compression stroke then drop a pencil in the plug hole. And rotate by hand. I figured I'd just use my adjustable timing light that way I'd only have to mark TDC, no? Then I could set all cells in the AEM to say 20*, then dial in 20* on the timing light dial. Should be spot on the TDC/0* mark shouldn't it?

Thanks!