Hey all,

I know it's a really complicated title, so I'll try my best to explain.

We're (slowly) finishing up my car and I've been test driving it over the last couple days just around the block, and whenever I come to a stop the tachometer starts to jump between idle (600rpm) and about 1500rpm. It feels like how a manual transmission does when you let out the clutch at idle and the engine starts to stutter and shake. I have to throw it in neutral for it to right itself, and when I shift back into drive the jumping of the tachometer goes away but it's a really jerky shift (lurches when it hits D) and then everything appears normal.

Does anyone know what could be going on? I have removed the ECM so the TCL isn't there, but as far as I knew this theoretically shouldn't make a difference unless I removed the ECM when the transmission was locked up. Also I've had a couple issues with what I believe is the transmission kickdown cable and how the line to the carb (Edelbrock 1406) isn't in a straight line, but I'll work to fix that soon. Any help is appreciated.