"Trailer-hitching" bucking problem, Rapid detrioration from running perfectly Options

[boxster914]

Hi everyone

My perfectly running 71 914 1.7 D-jet has deteriorated rapidly this past week.

Early in the week I noticed what felt like a power drop out during a drive. It was very slight and only happened once and I wasn't sure I didn't cause it by unconciously lifting off the gas.

The next drive it happened a few times and was more pronounced. It was then that I knew this wasn't an imagined problem.

On the third drive it was like a bucking bronco, surging and stopping and the engine cut out a few times. It was undriveable.

Today it will start but won't run. The engine cuts out when I try to rev it and the red light comes on.

I've done some searching here but haven't been able to draw any conclusions or come up with an actionable strategy to diagnose the problem. I'm seeing people trace it to spark plug wires, air fuel ratios and bad distributors.

Is there a step-by-step process that you can recommend for me to get to the cause of this? (I'm a newb so I probably will need help with abbreviations like AFR, TPS, etc.)

Here is a video of it's rough idle yesterday when it was still running.

https://youtu.be/n61CP6O8UgM

[Lockwodo]

Thanks Boxster914, very helpful to have the manuals, it's an amazing resource and insomnia cure (IMG:style_emoticons/default/biggrin.gif)

Wonkipop: I've done some research and it seems there are two ways that air bubbles can get into the gas line. One is a leak in the suction side of the fuel system, i.e. in the fuel line before the fuel pump or in the fuel tank itself, such that air is getting pulled into the line by suction. The other way is a failed injector combustion seal that allows combustion gases to force their way into the injector nozzle.