Need help with 89 blazer-stalls when put in gear after warmup

[chevyh20]

hi folks,
i have an 89 blazer that i use mainly in the winter for plowing. i used it a lot last year, and was running rough at the end of the year. it sat all summer. This fall i tuned it up with new rotor, cap and wires only. i found 1 wire was burned from resting on the exhaust manifold. So now it is running a lot smoother, BUT it has an annoying problem now that it did not have last year. It idles and runs fine when the engine is not warmed up. ( i have about 10 min to plow before the onset of the problem) When the engine is warmed up, it will still idle fine, but stalls when i put it into gear unless i keep 1 foot on the accelerator. This is very annoying and makes plowing a lot harder, as i have to work to keep the engine running while going between gears. i have done searches and found lists as long as my arm of what it could be. I have not done anything yet to try to fix it. I would like to proceed in a logical manner. The only thing i have noticed upon a casual glance under the hood, is there is no vacuum line going to the egr.
thanks for your help!

[zieg85]

Does your check engine light work?  Being a throttle body engine everything needs to be feeding the right info for the computer to properly determine the fuel/air mixture.  I would start there.  Could be just an O2 sensor.  Having a vehicle sit is the worst thing you can do to it.

[Captkaos]

as zieg said pull the codes and report.  I had one dying in gear and it was a number of things...

[VileZambonie]

Verify your firing order is correct. Why didn't you check/replace the plugs? Unhook the vacuum hose at the egr valve too and see if it makes any difference.