GCEZ28

Ok, so I finally disposed of my optispark last summer in favor of an MSD unit.
the car NEVER RAN THIS GOOD!! But.... Then it died. Car instantly developed a miss. The miss has a definite pattern so I thought distributor again.
I spoke to MSD and they say it is the ecm.
Where is the best place to get a tuned computer for my car? It is basically stock, air intake and soon some mid length headers.

RamAir95TA

The last thing you should do is believe anything MSD says.

A true non-programming-related ECM/PCM failure is incredibly rare. GM did their homework on them on how to keep them long lasting and reliable.

Research would tell you that MSD optis are hit and miss at best - many people have no more luck with them than any of the cheap eBay, Chandler, Accel, or other knock-off optisparks.

Chances are extremely likely that it's a crossed wire, unseated boot, or the MSD opti itself. If the PCM were bad the engine likely wouldn't run at all. What you indicate is typical of a fault in the ignition system.

95zsean

Did you scan it for code's? I'm with RamAir its the MSD Opti!!!

shoebox

The computer is usually the last thing that goes out on these cars. I'd look elsewhere for your problem (starting with the MSD opti).

GCEZ28

Crap.... Now I don't know. And the MSD Opti only has a couple 2 more weeks of warranty, Only had the car out for 2 months last summer when it broke again. any one else have any input?

Injuneer

Have you checked other possible causes of a miss with a "pattern" - plugs, wires, injectors, misadjusted valve, etc.?

GCEZ28

Visually checked everything. Still no code or SES light. But every time I have had ignition (Optispark) problems it has never given a code or a light... I am wrenchin' in the dark.

I was driving a steady 55-60 mph when this happened. Was not driving hard at all. Just a smooth steady cruise.. Then It was like someone flipped a switch. Engine started to stumble and the catcon started to glow.