code P0300

**neverlate** · 06-01-2006, 05:35 AM

'99 corvette engine falls flat on it's face for a short period of time then clears itself and seems to run pretty much ok.While this is going on the exhaust smells horrible.
Acceleration does not seem as strong as other vettes I have sampled.It seems to come alive but with a little delay.I was cruising at steady 60mph yesterday when it happened, this time it coded p0300 which was multiple random cylinder misfires.It lasted for a couple of miles. This happened when I first bought the car in Nov. and only three times since then but never showing a code.The check engine light flashed a little while before going steady and then the car was running smooth again.
The engine was changed in Jan. so it has happened with both engines.
The only reused parts from the old engine were the intake and the fuel injectors.All else was brand new GM out of the box.Plug it in and run.
I hope some one can help me because this car is about to break the 10k repair bills since nov.

**99m6t/a** · 06-01-2006, 11:36 AM

Man, I posted this same thing up on here about a week ago because my TA does the same thing pretty much but no one really replied to it.

Hope you have better luck with it.

**2001NBMZ28** · 06-01-2006, 11:54 AM

My car has thrown P0300 a couple times over the years, but just cleared the code and hasn't come back for several months now since the last time. Both you guys need to look it up at www.gearchatter.com maybe you can find an answer there.

**Mr. Luos** · 06-01-2006, 03:20 PM

I can't NOT throw that code.

It is a random misfire.
Plugs
Wires
O2's
Fuel

**neverlate** · 06-01-2006, 07:49 PM

I have a friend who is a service writer now that he is almost disabled from working on these ground hugging machines. He said it is most likely a fuel delivery problem and that a fuel pressure guage and hose assy should be attached to the fuel rail and taped to the winshield to observe the fuel pressure when the malfunction manifests itself. Record the reading and see if it falls within spec.The fuel pressure with the key turned on to cycle the pump then turned off should be 50-62 lbs. He feels it is a fuel pump getting ready to leave me stranded. The info at gear chatter is helpful if you have a GM scanner toanalyze the info,but it is informative.I am taking the car to the dealer Friday and leaving it until they fix it. I am so over this car. if it was the only thing I owned and it disappeared I wouldn't even go look for it.
Good luck

**Mr. Luos** · 06-02-2006, 03:52 PM

WOT you want at least 52-53 PSI.

**Scott Stookey** · 06-02-2006, 05:11 PM

P0300 Code is Mutiple Misfires detected

Try Changing Your Fuel Pressure Regulator Sounds Like The Diafram Is Sticking

If You Guys Have Any Other ? Feel free to Email Me sstookey@woh.rr.com

**Flobeast385** · 06-02-2006, 07:30 PM

My TA did the same thing and then run fine for a little while so i hooked the GM scan tool up to it at work and one of the O2 sensors was showing high voltage. That solved my problem by replacing it

**neverlate** · 06-04-2006, 06:48 AM

Last night I took a leisurely ride for about 50 mi. no problem . Jumped on the throttle got up to 70 mph and cruised it for a few more miles.Got off the main road and on comes the check engine light. Car feels like it has a slight miss so I scanned it again and here it is P0300 and P0420 bank one catalyst below threshold.
Now what???
It seems I am chasing a moving target with my ATM card.