Gm
Just picked up brand new 1990 2500 Sierra starts and idles great. Any revving will kill it. Previous owner replaced fuel filter, plugwires, plugs and cap. I put new air filter on and cleaned injector nozzles so the spray pattern is much improved but it will misfire with revving still.

From haynes manual it gave me a few ohm reading checks with coil and distributor ill check. Any other ideas someone want to toss? Much appreciated always. Truck is 2hrs away in federal way so ill stop by pickn pull and grab a coil and distributor on my way down tomorrow.

Jamie

With the truck 2 hrs away,bring something to check your fuel trims and psi also data. If it is running to lean it may have the issues you describe. A skewed sensor such as a MAF also. Just thoughts.

Define revving? At what RPM is it missing at?

Revving here means lightly opening the throttle. Im not muscle car nothing man just anything above 2000 kills it.
Ill get to oreileys and borrow some gauges to check pressure.

Make sure you don't have any vacuum lines and or fittings bad. Make sure the carb base gasket isn't sucked in.

Definitely check fuel pressure.

Also check (or maybe replace) the TPS.

Thank you everyone for your ideas and suggestions. I went back and previous owner said he couldnt get distributor( dizzy) exactly the way he took it out. Off a tooth.

I played with it long enough and its sort of odd but the seat or keyway inside the block would shift just about everytime the dizzy was stabbed in there so i had to insert it about 30 times to find it. Still idling way too fast. I just wanted to get it out of there so ill mess around later to fine tune it.

Long bed 700$ and i got some things i want to load up with it. Compost, barkchips, etc.

Odd tho that the keyway for dizzy would move so readily.

Thanks again.

The "Key Way" is the oil pump drive shaft and you can turn it with a flat blade screw driver to aid in installing the distributor.

Oilpump shaft. Right, i was beatn my head not knowin what to call it. Im a big fan of proper nomencletchers? Or terming things right..whatever the right word is here im tryin find, dangit, you get what im sayin