My 110k mile original opti had been getting progressively worse, refusing to start in the rain, and taking longer and longer to dry out. I finally scraped up enough money to purchase the MSD opti (after lots of searching and reading on this board), and already had MSD wires and NGK iridium plugs waiting to be installed, so I did it all in one shot. I also put in a 160* thermostat. A fully functioning opti is a thing of beauty to behold, the car started right up (yes I did in fact test it before putting the water pump back on!). My question is, for people with similar configurations, are you running any advance on the timing? I only run 93 octane and have had no computer tuning yet.

The instructions said it's out 2 turns from the factory, but mine, like many others on this board, was out 2-1/2 turns. I bottomed it out and turned it back a bit less than 2 turns (keep in mind 1 turn is 360*), but I'm wondering if it's retarding spark when I really get on the throttle. For part throttle it's really smooth and snappy to respond to input changes, and WOT it was really nice and smooth and churns the tires shifting (thanks CPT), but just didn't seem to have the punch it did before. I'm afraid to just hammer it from a stop and hold the throttle down WOT through the 1-2 and 2-3 shifts, I simply can't afford to break anything right now so I take it easy. I mostly baby the car and don't get heavy into the throttle that much, so I'd trade a little bit of low-end pep and highway cruising mileage (my main concern with the 160* t-stat is that I'll kill my mileage).

FYI, perhaps MSD has improved some assembly line procedures, all the bolts had a good amount of blue threadlock on them when I removed them. I did remove the rotor bolts, they were good and sticky right from the box but I reinstalled them with red loctite just to be sure.

I've got some pics of the old stuff I took off, I might get around to looking at them and taking more of the plugs and opti. The weatherpack connector was cracked where it plugs into the opti, perhaps the source of my wet-weather problems. I had strange buildup on the ground electrode of my sparkplugs. And, I found a really easy way to bleed the cooling system before even starting the car for the first time, it worked so well I'll take some pictures and explain what I did; I didn't even need to bleed the system after it was running.

The only way to actually know what timing the MSD is giving the engine is to rig up a timing pointer, verify with a scanner the advance the computer is providing and then observe the advance on the pulley. That's a lot of trouble. Some have noted that the screw does not alway engage properly and that would definitely skew the intended amount of advance/retard. That is one of the things I don't like about the MSD.

I agree. If MSD would make a non-adjustable version set to factory timing specs I would be much more inclined to buy it.

The optical module tends to bind-up as you add advance (CCW w/ the adjustment screw). As the adjustment screw is backed-out turning it CCW, by design an internal spring-loaded plunger is used to push the module to add advance.

The best option is to open up the MSD distributor prior to installing it and add some additional advance while observing the module and ensuring it doesn’t bind-up. Then, advance is removed by turning the adjustment screw CW until the timing is correct. Also, I used a fine-point Sharpie to mark a mechanical reference point (position) in the distributor housing for the module.

WD

I have the exact same feelings with mine. It just doesnt feel the same as it did before. I even backed it out an additional turn. I might try another turn or two and see what happens. Can a tuner adjust the timing through the computer to compensate a retarded MSD Opti?

I bet the Optical module isn't moving. I played with this while I had an MSD open. And typically, the spring-loaded plungers would-not push the module as advance was added. It would get stuck and not advance.

WD

IMHO, I would get the opti zeroed out to where it is providing no advance or retard. That would be the best way. The tuner would have to know how much to adjust it and you would still have to do the procedure I mentioned before.

WD, it was one of your previous posts I read that recommended bottoming out the timing screw then backing off, as simply screwing in or out the timing screw might not have the desired result if the thing binds. I didn't check to make sure that the screw was working properly however, so the worst case scenario would be that it's actually running more retarded that it should be?

It's great to have all this sophisticated computer equipment controlling the timing, but without a timing mark it can be kind of a pain. Sometimes simple is best: years back I learned to do timing with nothing but a vacuum gauge, it involved advancing the timing until reaching the maximum vacuum at idle then retarding it until vacuum dropped by 1". It was possible to get very good accuracy (basically limited to the accuracy of your vacuum gauge) using this method. The MSD instructions say that the computer will vary timing at idle and to make changes at 2000 rpm or so, would the vacuum timing method not work? It could at least be used to verify the optical module is moving, as you screw in or out the timing screw it should correspond to increases or decreases in vacuum. Does anyone even run with a vacuum gauge hooked up full time anymore? It's an incredibly useful tool IMO that can tell you a lot about how an engine is working without having to hook up a computer.

I have the boost/vacuum gauge hooked up and just leave it down by my feet incase i want to see whats going on at any time. I did check my opti to be sure the screw was in the right place and found 2 1/2 turns out gave me the best throttle response. When i had turned in more the tires were hard to break loose and to far out the idle was rough.

Can this procedure be done while the opti is on the car? I would hate to have to take everything back off...

i do all my tuning via tunercats and don't want the msd opti screwing up my timing. if the msd has advance or retard my datalogger wouldn't pick this up correct?

also msd says that two turns out is 0 advance and 0 retard is it safe to say this is correct. it seems to really check the timing is not easy on an lt1.

Right, the datalogger only tells you what the PCM is doing. It won't tell you what timing the MSD is doing.

so all i can really go by is if my msd screw is two turns out the opti should not have any effect on timing.

Drive it. When I installed mine I made 10-12 passes with a rachet long extention and swivill in the car with me. I drove it till it felt right. When I put mine on it bogged at low rpm, kinda a hesitation, so I turned it then it started busting out on top. After 10-12 runs it was perfect.

I agree, the most important thing is that opti is exactly where the computer "thinks" it is.....

if it is out of sync it will be bad either way....