I've got a 1990 3.1 firebird. It started to act pretty weird every time it rained. It would start up just fine and I would always get about a mile down the road and it would start to choke out and hesitate really bad, I would take it home, let it dry out for about a day and then it ran perfectly fine as if nothing ever happens. Just recently, while driving it, I tried to get down on it and when it hit about 3500 or 4000 rpm it died. I pulled over and it started right back up and drove it home with no problems. The next day I got in it and it was idling really rough and would die when revved up to about 4000 rpm again. It also seemed as if a cylinder was out. So i replaced the wires, fuel filter, and checked the plugs(they're not even a year old) and it was still idling rough and shutting down at higher rpm's. Then I thought that maybe it was the EGR valve, it did look pretty bad, so i replaced it with a brand new one... still no change. I finally gave in and took it to a shop to get it diagnosed, he told me that my distributor and the ignition coil was bad, I then replaced both of these and STILL have the same problem, and now it's getting worse and wont even stay running for more than 2 seconds. I finally got a hold of a friend that's a GM mechanic and he's taken a look at it and can't figure it out either, he did find out that all 3 cylinders on one side are out, but they all do get spark. We've thought that maybe it could either be the computer has gone bad, bad injectors, or maybe there's a wire around somewhere that's touching something or shorting out...... anyone have any ideas???

 

Hi, just want to let you know that if you ever decide to check out your fuel injectors, we will be more than happy to do that for you!
SouthBay Fuel injectors. We will clean and flow test them for you. You will receive a before and after flow sheet. Turn around is 24hrs. from the time we receive your injectors!
www.southbayfuelinjectors.com

 

Check the resistance on all of your injectors. I had a similar issue and It turned out that I had one that was starting to short out. I would look it up in a book, but I believe that the resistance should be somewhere between 11ohms and 13ohms.