OK this is about my family car,and its not a third gen cause my wife cant handle one lol.The car is an 1991 Chevy Cavalier w/ a 2.2 lt 4 cylinder.Now i noticed the car was running rough,sometimes missing at idle,and sometimes missing throughout the driving range,and missing when i accelerate,sometimes to the point where i almost stall and sometimes do.I changed the fuel filter,air filter,PCV valve,new plugs and new plug wires.To be honest i think the car might be running worst now.I did notice when i changed the plugs it looks like my 1st and 4th cylinders are barely firing.And it just happens to be the car has 2 ignition coils,and #1 and #4 plugs go to the same coil.#2 and #3 go to the other coil.Could the coil that plugs #1 and #4 go to be my problem?Desperately seeking help,thanks.Al in NJ...

 

sure sounds logical. there should be a value for the coil in your manual you can test it with a DVM.

 

Change the coil. They are relatively cheap enough. But it sounds to me like your vacuum lines are shot. My V6 would do the same thing unless I kept the revs high when stopped at a sign or something, and it usually happened within spitting distance of getting the gas it was drinking like it was going out of style. If you also have bad mileage that is where I'd start.

Also check some of the relays to see if they are bad. I am not sure whether the '91 has FI or not, but my dad's '93 does and it has relays all over the place. You might want to find and check the one for whatever air sensor the 2.2 uses, it may be shot, causing these problems (I know that it does on my V6 for sure).

Forgot to add: Get a tech manual and pull the codes from the ECM. Those will usually point you in the right direction. The ALDL is the same as the one for our thirdgens, but it is pointed at the floor and is turned to pins A and B are closest to the firewall on the passenger side.