View Full Version : 91 chevy 305/ engine miss?

08-05-2006, 11:19 PM
Info : I have a 1991 chevy caprice, 305 engine. The miss ( more of a surging) occures when driving at any speed or any gear selection. This only happens when applying slight throttle. Under accel. engine runs fine. Have replaced the usual items. plugs, wires, cap, rotor, fuel and air filter. The only modification from stock is the cat was removed 3100 miles ago. Miss started about 150 miles ago. miss hasn't gotten any worse. There isn't any back-firing when this happens. When i changed plugs, all had the same color and no carbon build-up. Engine starts and runs great otherwise. Hopefully someone has experienced the same problem and can save me from that old try and see approach. LOL

08-06-2006, 12:13 AM
having no catalytic converter the computer will see that. By removing it you'll loose horsepower. And not good for the environment.

08-06-2006, 06:55 AM
automotive emissions destroying the enviro? i dont think so. jets do more damage than all other internal combustion engines combined. do jet engines have a cat? thanks for your concern

08-06-2006, 10:24 AM
The exhaust backpressure can affect the EGR valve which can cause a surge. The advice you were given may or may not fix the problem but needs done because it does affect the computer, can cause your problem, is probably illegal to leave off, and does affect the environment.

08-07-2006, 07:20 PM
maybe it could help you but inspect carefully your distributor some got busshing problem... look under your cap for the parts with wire to make sure its not crack are look damage....in many cause the distributor himself is the problem i have see twice of those problem so take a good look there .... exhaust will not make miss your engine ...good luck

08-07-2006, 09:33 PM
If it's a miss-no, exhaust won't affect it. If it's a surge then the EGR can cause it and the missing convertor can cause the Egr to open too fast. I honestly doubt the convertor is the culprit mostly from the mileage frame, but leaving it off can cause a back pressure problem. Be careful to keep #5 and #7 wires from laying next to each other though.


08-07-2006, 10:24 PM
Sometimes you can notice a misfire type event at higher rpms. If you recently added new spark plugs and wires. And mistakenly put 2 wires in the wrong place. Overlook your firing order. Make sure the correct wire on the distributor cap goes to the correct spark plug.

going clockwise 18436572

left side of engine 2,4,6,8
right side of engine 1,3,5,7