jmkopac

i just purchaced a real nice 97 30th anniversery z28 6 speed. ...... problem is it wont run right. i dont know much about the motor exept it has a k&n cold air intake and it had no convertors on it until the guy i got it from took off the moroso muffler and added the convertors back to the car... he said the car ran fine for a couple days and then it just started to run ruff. he said the codes came back . misfire in the num. 1 cyl and 5 cyl and i guess they randomly go back and forth misfiring. i can here a miss in the engine when i fire it up. and it pops back sounds like exaust and sometimes throttle body that its poping thru. any ideas where i can start to look to solve this problem?

97FormulaWS-6

How many miles are on it?

From what you're saying I'm thinking it needs a new set of plugs, wires, and probably an Optispark (distributor). Very typical problem on these cars.

jmkopac

i apreciate the input and will definately give it a try. is there a brand that i should stay away from or a brand i should definately try to find to put on it?... thanks for the reply... it has 122000 on it

97FormulaWS-6

Personally I'd get an OEM one from a GM dealership; they're not cheap.

I've heard mixed results on aftermarket pieces; but have heard decent about the MSD unit. You need the whole unit though, not just the cap.

Search on here for Optispark Replacement and you'll get TONS of threads.

Z28SORR

Why don't you do some trouble shooting first, to find out what the problem actually is. Before you waste money on parts. What if it's just dirty injectors???

jmkopac

it was pluged into a scanner. and all it will read is a misfire that goes back and forth randomly between 1 and 5 . ... i dont know what other trouble shooting i could do