Starts up, idles, surges, dies - please help!

[Sehrgut]

I just got my 1984 944 NA back from having a rebuilt alternator installed. The shop called and said it's running rough all of a sudden. It was okay when I took her in. a little idle fluctuation, but nothing big. Was a bit sluggish upon acceleration too but picked right up. Now it starts right up every time, idles for a minute or two, has these HUGE surges, and then dies. No throttle response when surges are happening. I can shut her off and re-start easily and the whole process repeats again. Mechanics told me to bring her back and they would "troubleshoot" her -for more money I am assuming. They think it could be AFM problems. I completed the Clark's Garage AFM tutorial with no problems there. I trust you fellow Pelicans for better advice than the local shop. Please help me diagnose and fix the problem as she is my daily driver. Your time and expertise is greatly appreciated. Many thanks - Vielen danks!

[Sehrgut]

Addendum: Surging/bucking, dying also occurs when revving engine or holding at higher than idle. Engine does not recover when adding/tapping throttle. It just continues violent surges and dies if I do not shut off ignition.

[sausagehacker]

Sounds like maybe a vacuum leak or an idle control valve malfunction?

[txhokie4life]

Throttle body cable disconnected?
Possible vacuum leak in the intake area?

Look in the areas that had to be removed to replace the alternator. That would be the air intake box.

Mike

[fiily]

Look at all of the connections made to your J Boot, also under the throttle body there is a vacuum hose that attaches there, easy to miss while reconnecting stuff around that vicinity.

Is those all look good, verify your BOV vacuum line/hoses are on tight, and follow those to your fpr and give everything a wiggle there to verify all is good also.