420A Check base timing with timing light on 420A

[Chris072901]

Hey guys, might be a newbie question but I need to see how yall are doing this. Basically I've got a 1998 Eclipse GS with the 420a. I installed a gt35 turbo from max speeding rods with an 8 psi wastegate. I have some RC 650cc injectors and walbro 255 fuel pump all being controlled by a megasquirt 1 with the v2.2 board by B&G.

I got all my wiring and everything done and getting ready to try and start it but I want to verify my ignition timing before I fully fire it up. How are you guys using a timing light to check the ignition timing on the 420A.

I don't have my original timing cover so I don't see any timing marks to align my crank pulley timing mark with. Did the OEM covers have timing marks on them or am I supposed to be refreshing somewhere else for my ignition timing.

Any help is much appreciated and I'm happy to provide any other info yall need from me.

 

[BLACK'98DSM]

The ignition system / timing control is totally electronic. There aren't any mechanical aspects. So you wouldn't use a timing light.

You seem to be confusing the mechanical timing of the engine's rotating assembly with the ignition timing. They are separate systems.

Your ignition timing is written in the tune. Since you have MegaSquirt, did you not input these values yourself?

 

[Chris072901]

Megasquirt's option is to use the 420a wheel decoder which auto calculates yes but I just want to verify that the -10 degree timing is indeed -10 because there's a way to basically calibrate it.

I know the original ECU did everything electronically but I was curious if there is a mechanical way of checking. But typically I see on the timing cover a piece that goes retard and advance so you can set up your ignition timing, I know that's typically on setups with a distributor and where ignition timing is actually mechanically adjustable but wasn't sure if there was a way to check on this motor. I just wanted to make sure when I programmed -10 degrees that it is truly -10 degrees

 

[Brad Bell]

Did you figure out how to confirm the base timing? I've been running MS2 standalone for a few years but never checked my base timing with a light. Has always ran well so never found a need to.

I assume you would setup a timing light attached to cylinder #1 wire, set fixed timing to 0 deg, then crank/run engine and shoot light at the camshaft gears to see if the TDC marks line up. Adjust trigger offset if needed to get marks to line up. This is assuming the engine is physically timmed correctly between crank and camshafts.

 

[Chris072901]

This is exactly how I would do it but checking on the crank pulley not the cams, theoreticlly shouldnt change the results though, I eneded up swapping plans to a k24 but otherwise you would need to index the crank pulley and use that for reference