Engine running REAL bad

Ok, heres the situaion.
90 GMC Jimmy S15. 4.3L
With the MAP sensor off, the engine will run, sometimes OK, sometimes very ruff. After it has warmed a bit, it will bog down drastically.
With the MAP on, it chokes out.
I've replaced the MAP so that eliminates it.
I've been told I may be looking at the Computer

Any Comments?

Thanks
Dave

I would tend to agree. One of two things is bad or going bad the computer or wiring. I would check out the wiring first though.

Ok, heres the situaion.
90 GMC Jimmy S15. 4.3L
With the MAP sensor off, the engine will run, sometimes OK, sometimes very ruff. After it has warmed a bit, it will bog down drastically.
With the MAP on, it chokes out.
I've replaced the MAP so that eliminates it.
I've been told I may be looking at the Computer

Any Comments?

Thanks
Dave

Ever done a tuneup?