I did a search and nobody has described these symptoms, and all diagnostic info seems to be for can't start conditions.

Symptoms are:
Rough starts. Needs a little foot in it for the 1st 10-15 seconds.
Rough running while cold.
Seems to be a little down on power.
When easing the pedal to wot from 2-2500 rpm's it's lazy until around 3500-4 and it seems to suddenly pick up.
After running wot and coming back to idle, it idles erratically for a few, or want to stall.
Last plug change plugs read very different between cylinders.

Opti is 5yrs old and has less than 5k on it.
I've already heard I should junk the MSD coil.
Just wanted to get a few opinions from some of the experienced board members before I start taking the thing apart to look at it or throwing parts at it.

 

Check your fuel pressure.

 

fuel presure has been checked.

 

If you purchased your opti brand new and it's OEM, I wouldn't be so quick to jump to that conclusion as opti failures are very over rated and it's usually misdiagnosis or people using cheap taiwan opti's which are known to fail regularly.

What fuel pressure do you have at idle and WOT? You can leave the gauge on there and fit it under the hood and have somebody ride along with you to see what the gauge does under load.

How old is your fuel filter?

I have heard a lot of bad things about MSD coil's also. Test the coil as described on shbox.com. You should have 5-8k ohm's on each terminal, just be sure they're consistent.

Are you throwing any codes?

 

Needing foot to start and erratic idle I would be looking at the IAC rather than blindly blaming the opti.

 

IIRC the IAC has no effect on the engine at WOT.

I think he has a fuel shortage, misfire, or weak spark.

 

Opti was a new GM unit in '05.
fuel pressure sits at 42lbs and never changes.
good point on fuel filter it's original as far as I know. will change this weekend.
will also check coil terminals, or swap in my old stock coil.
only code was from me rushing to get car out of storage and forgetting to plug in MAF when putting intake to filter back on.

 

thanks, I already checked the IAC and played with the throttle blade screw to prove it.
The erratic idle is more of a not wanting to keep running, or coughing when throttle is given than an rpm issue.

 

You can swap the coils out now as that's a quick check.

I would run a stocker anyway, as there is no advantage to running an MSD coil.

 

If your fuel pressure never changes, you forgot to hook up the vacuum compensation line to your fuel pressure regulator.

 

The vacuum line is hooked up. The pressure is lower when I turn the key, about 38lbs. Any time the engine is running it's 42lbs.
Do you think the regulator is bad?
I thought the hotwire kit from the alternator sending more voltage to the pump was giving me steady pressure and that was a good thing.

 

Checked coil as described on shbox.com. Except for my coil being a 3 terminal. All 3 teminals checked 5.99 ohms, so 5990 was the final reading and dead consistent so the coil should be ruled out.
I couldn't find my stock coil to swap it in. Probably sold it to some guy on this board.
New fuel filter is also swapped in.

 

At idle, the fuel pressure should be in the range of 41-47psi, with the vacuum line disconnected. When you reattach the vacuum line, the pressure should drop proportional to manifold vacuum - about a 6 to 8psi drop with a stock cam, lees drop with your cam. The pressure should then vary with throttle position as you drive. That is the purpose of the vacuum compensated fuel pressure regulator - NOT to maintain a constant rail pressure, but to maintain a constant DIFFERENTIAL pressure between the fuel rail and the intake manifold.

 

Fuel pressure update: checked again with a higher quality gauge.
turn key prime up to 45 and drop to 40.
start and idle 43.
goes up to 45 with vacuum line detached.
cruising 2500rpm is at 42-43lbs.
hard accel is 45, dropping to 42 if i let off to shift.
Spark plug check on new plugs is as inconsitent as the last set with the rear cylinders looking the darkest. 6 and 8 are the worst, with 7 in 3rd. Middle and front finally look better with this 2 ranges colder set. "pepper" look is gone from ceramics.
Still thinking weak spark.