I'm having a hell of a time trying to figure out what's causing this problem with the 350 TBI in my pickup. Here's what happens:
1.)I get in my truck and start it up,
2.)I put it in gear and start driving down the road,
3.)Once I reach 2K RPM the engine stumbles and the tach needle dives for a moment.

Here is where it gets weird I think. The engine doesn't stumble at any other RPM, it's always 2,000 RPM like clockwork. On top of this, the engine only stumbles at 2,000 RPM AFTER being started up. In other words, after it stumbles the first time, it won't do it again UNTIL I turn the engine off and then restart it and bring it back up to 2,000 RPM.

My engine is mild, most specs are in my sig but if there is anything else I need to provide for details I certainly will try.

Please help

Thanks in advance.
-Chase

 

is there any rust on the pickup coil? if not it sounds like a glitch in the ecm.

 

What exactly is the pickup coil? What kind of glitch in the ECM and how would I fix it, replace the ECM? I have 2 or 3 extra 747 ECMs laying around but they aren't equipped with the sockets for chip swaps like the one I have in the truck now is.

I replaced the spark plugs a couple days ago with ACDelcos, checked the initial spark advance at the dizzy last night w/ the EST unplugged. I don't know what to do at this point.

 

remove the distributor cap and rotor. look for rust under the rotor. those distributors are bad about that. if you have a spare ecm try it. it may run bad but if the misfire goes away you'll know the ecm is the problem.

 

Well I borrowed a timing light from my friend and turns out the distributor shifted from the 7* initial advance that I originally put it at, to 2*. I burned a chip with the ISA (initial spark advance) set to 2* instead of 7* and this seems to have fixed the problem.