Engine stumbles and sometimes at idle it surges and stalls.
by Jonathan Lester
(Ft Lauderdale, FL)
I replaced the module and distributor pickup with new ones and it got worse than it was before with the old ones. On acceleration during normal takeoff it stumbles and actually cuts of and on and then goes like hell when I stomp it. At the time it stumbles the tach also jumps. I can duplicate it at 1200 to 1500 rpm in neutral with no A/C on and car not moving. I double checked all connection on the distributor and coil and all plug wires. The reason I replaced the Pickup and module was because when hot the engine kept stalling at idle and it kept surging if it did not but it was OK after it cooled down for an hour or so. That problem is gone now but the new one I mentioned is driving me nuts.
Thanks for any help you can give me.
1990 Corvette 5.7 vin 8 Convertable 6 speed standard.
P.S. I also noticed under diagnostic the ignition timing read out seems to jump around more than it should and car runs worse when cold.