Engine stubbles at idle speed

On left side of throttle body, is the Idle air control valve. It acts like a coke. It is possible that the connector is off or passage is plugged. Very small screws that break easy. Not a good thing to work on on the road!

Next possibility is bad plug wire(s), cap and rotor

Bud it's a TBI.

No codes sprayed all vaccum lines on upper engine block no increase in rpm.

Look everything over on the engine. At that age you may have a rotted hose. Be gentle.

Sounds like a vacuum leak!
Mass air flow sensor?
Any codes? No codes more apt to be vacuum leak.
1996 P-30 8.1 TBI or port injection?

Check the distributor and vacuum advance?

rjxj wrote:
Be sure fuel pressure is correct first

I am on the road out west and have no gauges, if I floor it up a hill it is getting gas and runs well so I think fuel pump is fine. If I put it in neutral at a stop light idle is good and stumbles slightly when put in gear.

Be sure fuel pressure is correct first