951 engine surge when throttle is depressed

[gbrown0416]

I have an '86 951, pretty much bone stock. I've replaced all vacuum lines, put in an MBC to remove the stock CV, replaced the intake gaskets and checked her for vacuum leaks. She's been running a bit rich,but only at idle. So, I haven't given that much thought.

Here's my problem... The other day, I went to start the car and had a bit of hesitation. Once I stepped on the throttle, she began surging (like I was increasing and decreasing throttle (Think Zoom, Zoom)) at about 1200 RPM. The car idles fine ~800 RPM, but begins surging as soon as the throttle is depressed. I can't accelerate above 1200 RPM, as the car continues to to surge between 1k and 1.2k RPM, no matter how much throttle I give it.

I figured it was a fuel delivery problem, so I cleaned the injectors, replaced the fuel filter and blew out the lines. None of these things worked. I re-checked all vacuum connections and everything looks spotless. I'm still thinking along the lines of a fuel delivery problem, though.

The TPS was replaced about 500 miles ago, so I doubt that's the problem. In fact, I disconnected the TPS and the symptoms didn't change. (It just idled worse)

I'm about out of ideas for troubleshooting and could use any ideas someone may be able to throw out there.