Weird Miss in Engine

[rickstark]

I've been a lurker here over the years, learning how to do many tasks and now I need your collective intelligence to solve a problem...
Once my '85 Carrera is at operating temperature it will act like all electrical power is intermittently shut off. It lasts a few seconds but the car bucks and then power is back. First thing I replaced was the DME relay. Not it. Inspected the distributor cap and rotor. They're acceptable. Just got back after driving around the neighborhood after replacing the DME, the car got warm, and the miss/bucking is still there. Let it idle in the garage and the car would stop running for a nano second at idle but keep running, until it finally died. I immediately started it and it idled fine.
Getting ready for AutoX season I changed oil and fuel filters. I did a full top end/ rings a few years ago. Replaced all crank sensors, had injectors cleaned among other things. Steve Wong chip. I have never replaced the fuel pump.
Help! What is going on???

[freeform911]

Grounds? The bundle on the manifold under the heater blower..on my 86 it didnt get retighten and caused the same type of issue..
Not sure if the grounding strap from transmission to body can cause it but worth a check...

[proporsche]

start with the basics remove and clean your idle control valve...also check the red connection port at your battery if it is all tight....and one more thing the ground on the intake number 1
Ivan

[gomezoneill]

Distributor pick up?

[GH85Carrera]

That sound like the classic DME relay issue. Replace the DME relay, and I prefer the new solid state version. Don't go for the cheaper relay, get one from Porsche or the folks here in the USA that sell the solid state one. A little searching her on Pelican will find that seller. I don't remember off the top of my head.

[Kevin Saunders]

If you have the old style fuses, try spinning the fuel pump fuse (number one in my 77 911S) they get corroded very easily.

[Nick Triesch]

Tighten the intake runner bolts. Over time they get loose on our air cooled cars. If loose will definitely cause a miss. Get a cheap torque foot pound wrench from Harbor freight. Inexpensive thing to try.

[Nick Triesch]

I changed my cheap fuses to the German ceramic kind. Made huge difference in my AC. Ceramic will not melt.

[rickstark]

Replaced DME, checked all the grounds I could get to, battery and around motor, and thought I would check the spark plug leads. Well, two were incredibly easy to pull off, damn near loose. I crimped the connectors to the plugs with a needle nose and went for a long drive, no miss. So, problem solved...I hope.

[stlrj]

Originally Posted by rickstark

Inspected the distributor cap and rotor. They're acceptable.

But did you inspect inside the distributor cap for signs of carbon tracking? It's a common problem inside distributor caps and the reason manufacturers eliminated distributors.

[gomezoneill]

Distributor pick up again?