ok so i have a 1997 z28 with new plug wires, e3 plugs, optispark, coil, icm, cps, fuel pump.

ill start from the beginning i was driving to work the other day and it started running funny for a second and then it proceeded to backfire and die. car cranks strong and tries to fire but wont actually run only plubs below 500rpm for a second or two the dies or backfires...

 

Try checking the catalytic converter, mine did the same thing and thats what it was. While your at it might as well change the fuel filter.

 

ditto, cat converter did that for me too.

get a hammer or something and hit it the cat, listen for rattles. thought most cats will hiss, this one will rattle

 

Did you install all those new parts BEFORE or AFTER is stopped running?

 

Are you sure it is ignition? I wouldn't rule out fuel... did you run a fuel pressure test?

 

Sounds like fuel pump, either add fuel via intake or spray some starting flued see if it fires...

 

Have you scanned for trouble codes? Did you loctite the rotor screws? LF

 

hey guys just an update still no luck. sorry forgot to list changing fuel filter. car also has k and n cold air setup and flowmaster single 3in cat back and deleted cats. took timing cover off yesterday to check chain and gear alignment. chain probably needs changed but gears seem to line up so long as the diagram i saw online was correct and the crank timing mark is always two teeth counter clockwise from the tooth that lines up with the keyway in the crank position sending ring. just because i cant get that bugger off.
car isnt sending any error codes. problem started before coil, cps, fuel pump and filter. dont have a fuel pressure gauge but line seems to have plenty of pressure when you turn the key because i pushed the schreder valve down on the line at the back of the fuel rails and it shot fuel everywhere. my icm and opti are both warranted so i am gonna put the cover back on and try replacing those again, a good mechanic once told me that if an electrical component is going to fail most likely its within the first 30 days.

 

Pressing on the shrader valve does not tell you that you have good pressure. A gauge is necessary.

 

i will try to get ahold of my friends fuel pressure gauge as soon as i get it back together.

 

Appears the problems started after you installed "new plug wires, e3 plugs, optispark". Was the Opti a genuine GM part (AC Delco or Delphi) or was it an aftermarket or a rebuilt unit? Why the E3 plugs.... ? Did you Loctite the Opti rotor before installing? Have you examined the Opti harness connectors for corrosion or pin damage?

Then you started installing parts to solve the problem..... what diagnostics lead you to the coil, IC module, CPS and fuel pump? Why change the CPS? It's only there to detect misfires.