Sprintcar, is your MSD unit part #8381? Mine has the early style opti, and that's the one it uses. It has the splined shaft with a flat spot. GM made a design change about midyear 94, and the connection on the new style is a shaft with a cut-out hub...way different.
The rotor position on the new distributor (MSD or not) MUST be in the same position as the original. If it isn't, then sum-ting-wong!

 

Yes, it's 8381. That is the correct one for my car. I know this because
I also ordered the later version from JEGS because of the rotor issue
thinking perhaps I had the wrong one in the first place. So, I have both
MSD units in hand, neither work, (the later won't even fit the engine....it's obviously the wrong one) and I have to order another. My bank account
is dying here!

100% convinced now this is a defective unit. No other explanation.

 

jegs should take it back and credit your account. so u have not tried it to see if it runs? at what angle is the cotter key hole at. should be about 20 degrees off to the driver side from straight up at tdc.

 

Yes, I tried to start it with MSD in. Did not start. Then I put the original GM unit in and it fired right up. Ordered new unit today

 

wow never seen that before. they better give your money back. lol.

 

OK, Got the opti changed out with a new unit and fired it up. She ran
great. I put a new serp belt on, new tstat, new waterpump and replaced
a leaky p/s pump all while I had it apart.

I took it for test drive and it runs alot better, but still a problem.
When you load the motor it starts pinging (pre-ignition) alot. It
drives fine as long as you don't put a load on it, but pings like mad
if you get on it some.

I used a vacuum pump to check the EGR valve and it doesn't open. Looked
and it is carboned up alot. Btw, Scan tool (borrowed a Snap-On Modus) doesn't show anything.

Am I on the right track here? EGR cause pre-ignition??

 

clean the egr. that should help.

 

If the EGR doesn't help, take a look at your knock sensor next. Under normal conditions, the sensor should take care of pinging by retarding the timing, before your ears ever hear it.

 

Thanks guys. I'm old school and I'm just going off what I read on this
car. I wanted to mention the knock sensor, I'll look at that next.
From what I've read, the knock sensor is often blamed, rarely the problem
which is why I looked at egr first. If no go, it will be next on the list.

BTW, an opened up cat wouldn't have an effect would it?

 

No, but a restricted one could.