1991 Acura Legend: new transmission, stalls at stops

Right after the transmission was replaced, it started stalling at stops, idling low and trying to die. I parked the car in my drive way and it refuses to stay running since. When turning on the car, you have to keep your foot on the throttle to keep it alive but even then it only stays alive for a few seconds, idles low and just shuts off. We tried to diagnose the car using the cars obd1, but its not throwing any codes. We do know the EGR valve isn’t working like it should. Any thoughts?

Please clarify

The egr passages are plugged?

The egr valve doesn’t work at all?

Constant egr at all times? . . . this will certainly mess up your idle

I was thinking the torque converter was what helped the engine stay running when coming to a stop, at least on an automatic.

If so, could the torque converter possibly be the problem here? Maybe not installed properly?

Guess I shouldn mention it’s a manual

Have the mechanic check every connector he can see in the engine compartment.