p0300 missfire

[falcz420]

Here's the situation. I have a 98 GTP with a 175,000 on it and i get a blinking CEL when going 60-70 mph. There was a miss at WOT, and I found a bad ign wire on cyl 6 so I've changed everything on the ignition system, new Coil packs (used standard DR39), new ign mod (used standard LX364), new ac delco wires #9726RR, new ac delco plugs #41-101. Now that everything is replaced the Miss is gone the car runs like an animal but the the CEL is still doing the same thing and I'm still getting code P0300. Any Ideas? Fuel Inj maybe??

 

[dsmuts]

If it has an all new ign system then it has to be fuel related. Try some seafoam and a fuel filter.

 

[Explicit_Spade]

I would check the injectors first, then pump, and worst case, Crank position sensor.

 

[BillBoost37]

CKPS is ~$25 and easy to swap. Fuel pump can be up to $300. I'd label the pump more "worst case" than the sensor.

 

[falcz420]

OK, I just did a fuel pressure test at the rail and I'm getting 44 psi on key on and it stays at about the same when started and left at idle. When I put it under load it spikes to about 48 and then settles back to about 44psi. Any suggestions?

 

[dsmuts]

Injector problem? Could be a ckps maybe.