I recently put an msd optispark in my car, Is there any way to check the timing?

I know you cant adjust the timing on a stock opti but the msd has a little screw to play with it.

 

Now you've discovered one of the MSD weaknesses. There is no "0" reference, so you have no idea where it's set. MSD suggests a certain number of turns out or in or something. To accurately check it, you would have to install a TDC mark and degree marks on your damper, hope the unkeyed damper doesn't move, and install a pointer on a water pump bolt to reference the TDC mark when viewed with a timing light.

 

In other words a major P.I.T.A. fred couldn't he use a laptop and datamaster too see timing at any given rev? Just food for thought. I know it shows my main spark advance at all times

 

for stock timing its 2 full turns counter-clockwise from tight. If you play with it too much it can rattle loose by the way.

 

The PCM tells you what it wants the advance to be. But it doesn't tell you what it actually is. Since the MSD "timing" adjustment appears to offset the optical sensor from the true cam position, what the PCM sets is not what the timing will actually be. It could be plus or minus 5 degrees from what the PCM is commanding, and there is no way to check it without a valid reference to crank TDC.

 

Kind of a different subject but my car will be running fine then it just shuts off. It always starts right back up. Its done it to me driving and just at an idle. Whats up with that?

 

Im pretty sure the m.s.d has references as to what is what. So in datamaster what im seeing for timing is false because it lacks the ability too calculate for th opti-adjustment

 

Fyi: my original timing chain was stretched at 70k miles.

 

same problem, i thought it was vats related turned out to be a bad icm

 

I just put a new icm and crank position sensor on it a couple of weeks ago.

 

What does that mean?

The PCM sets the timing on the assumption that the optical cam position signal is referenced correctly to TDC. The only way the TDC reference would be valid if you change the timing in the Opti would be if you set the Opti advance to compensate for a cam that was not installed straight up.

 

ohm it against a good one, mine was a bit low can't remember which pins but I want to say a and c, also cleaned the key chip and sensors on the ign. switch, there was a bad connect with the fuel pump at the 3 prong (sending unit) which I cleaned up but I dunno if this would cause the comp to shut the car down like it was doing and very intermitent, dropped a good used oem icm in off ebay and no prob since