Pontiac Repair: severe issues with a 1998 firebird, spark plug wires, crank shaft

Question
QUESTION: HI
I have a 1998 Pontiac Firebird 3800 V6 and recently i took it on the highway and it broke down. The service engine soon light started blinking and the car started to lose power and eventually died. i pulled off and had an extremely hard time diagnosing the problem. turns out that the head gaskets had blown and it had two bent cylinder rods. I had the engine rebuilt. it drove good for about a month and then i took it on the highway again. the service engine soon light came on again and i pulled off. It runs rough now. some days it will be fine when i drive it and other days it will run horribly. when i was driving it tonight it was the worst its ever been. i got it up to about 45 mph and it started to act up. then the service engine soon light started blinking and i figured it would quit eventually like it usually does but it didn't. then i started to worry and before when something relatively close to this happened i stopped and put the car in park then revved it a little bit and it stopped. this time when i pushed the brake to stop the battery gauge dropped into the caution level and the dash lights dimmed. i gave it some gas and the meter returned to normal but the car was still acting up. i am fairly sure this problem is electrical but am not totally sure and cant get an accurate diagnosis no matter how hard i try. a hand held code scanner reads "random/multiple cylinder misfire". it read the same thing before the entire engine was rebuilt. please help me figure out what the problem is. Thanks

ANSWER: Hey David:

From what you said I would agree an electrical issue but what. I would start with the basic stuff like check all the battery cbales are right bothe + and -. make sure the connetor going into the ignition module is tight. make sure none one the spark plug wires are burnt on the tops of the coil packs. if you had a actual scan tool you could see which cylinders were misfiring. You could have a bad crank shaft sensor or an ignition module.. I'm just guessing here with out seeing the car it's hard to say exactly what the issue is. It's a bit strange that the alternator stopped charging as well. I'm sure the 2 issues are related. good luck :)


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QUESTION: Thanks so much for replying! I understand that you aren't in person which makes it extremely hard to diagnose a problem. when the engine was rebuilt all this stuff was put in new ignition module, injectors, plugs and wires, coil packs, crank sensor and much more. two cylinders were replaced. just last night my brother and i unhooked the front part of the ECU. then put it back after not being able to see if anything was wrong. now it runs so bad i cant even drive it. i have dumped just about everything i have in this car and i really need it to run right. Thanks.

Answer
Do you know what trouble codes are setting on this when it's running rough? Tht would narrow the problem down. I'm sure a p0300 is setting with is a random misfire code but what else? This could have a bad crank shaft position sensor cauing the issue or a Cam sensor etc.. untill you know what codes are stred it's hard to tell you where to start looking.. Did you check the fuel pressure and the fuel quaility If you got a bad tank of gas that could be your issue If the fuel pump is not putting out enough pressure/volume that could be it etc....