At wits end on this one, bricksters, so any help would be appreciated.

When I first start the beast, it kicks right over, starts on first turn almost every time, and purrs wonderfully for the first little while. As the idle starts to lower, however (we're talking maybe 15-30 seconds) it starts to miss, sputter, and will not hold an idle. Just dies if I'll let it. It won't stay running until it's been warmed up for a good while. Even when fully warmed up, it misses badly quite often, causing it to really jerk when accelerating away from a stop, etc.

Recent work done: engine wiring harness replaced, which necessitated removal & cleaning of throttle body, intake manifold, injectors. All seals & gaskets replaced with new when put back together. New cap, rotor, plugs - plug wires are recent as well. Exhaust manifold r&r'd while I was at it, & cat-back exhaust system replaced.

Thanks in advance,

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1981 242DL B23E 268K mi.

Had a K-Jet that developed a stuck coldstart injector. Very similar symtoms. Are you seeing any black smoke or smelling nasty partially burned gas smell?

I was all ready to guess that it was the intake manifold gasket until I read that this had just been changed. It's still worth checking.

You check for intake manifold leaks by warming up the engine and then spraying a flammable substance around the junction between the manifold and the head. If there is a leak, the engine will smooth out and accelerate when you spray flammable material where it will get drawn in through the leak. This approach will find a leak from a damaged or unplugged vacuum hose also.

Remember that chlorinated solvents like brake cleaner and carburetor cleaner are not very flammable, but may work. Starter fluid is ether, which is very flammable and works great but is a little dangerous to spray where there may be sparks. Wear safety glasses, be careful.