Originally Posted by NTXw123300D

New to me 85 fed 300D turbo had intermittent tach issues. Found this thread and decided to pull the EGR controller and try the jumper wire trick.

I know my EGR valve is bad, assumed failed closed and finally blocked off as of today. I plugged all the EGR vacuum lines last month to see if I could get it running better. I felt it ran worse but never reconnected the lines. Figured I didn't have much to lose by pulling the EGR controller.

The EGR controller and connector had tons of green corrosion. I regret not taking pictures at this point. Cleaned up the connector, installed the jumper wires and got my tach working great, however now it won't shift out of 1st gear, which shocks me.

I cleaned up the EGR controller pins and put it back in. I lost my tach again but it shifts exactly as it did before. I'm not grasping why it refuses to shift without the EGR controller installed.

Since then, I bought 2 EXACT same EGR controllers off e-bay with NO corrosion at all, and it still DOESN'T shift out of first gear, but the tach works...

Of course, still running off the original EGR controller so I can drive the car but have no tach.

Any thoughts?