Put a brand new fuel filter in the Vette today and WOW, it made a huge difference. My idle is silky smooth now whereas I used to get a free deep-tissue massage at every red light courtesy of the LS1. My old fuel filter only had 25K miles on it and GM says there is no maintenance interval for the filter (meaning you should never have to change it). This fuel filter swap, in addition to changing to Redline in the gearbox and diff has made a HUGE difference in the daily drivability of this car -- I wish I would have done these things sooner.

Now, my question -- would the additional fuel load demanded by a supercharged application cause any oddities in the fuel filter? Premature wear mainly? I am trying to setup a maintenance schedule for my car and I'm thinking that the fuel filter will be done every 20K miles -- not that it's necessary, but just to keep the car running smooth.

Also, under what conditions would the PCM give P0300 (random misfires code)? Could it be related to fuel delivery and not just spark? The reason I ask is because P0300 came out of the blue in the last couple of weeks and since the fuel filter swap that code hasn't been fired again. It might be too early to tell though since it only happened once every 4 or 5 days.

Anyway, now I know what everyone meant when they said they went supercharged to maintain driveability! My Vette purrs like a kitten now and rides as smoothly as my Cadillac (well, until I start moving that is, but I like my car riding on rails)! :cheers:

 

Did you recently put a new fuel pump in?

If so, that could have caused some debris to get in there.

If you have a late 98-2002, you just changed your fuel pressure regulator also (it is inside the filter) and that probably has more to do with it running better than anything else.

And yes, misfires at idle are a/f related.

Some trivia:
A misfire just means that he PCM noticed the crank slow down between certain cylinder firing points (pretty easy to detect this at idle). Any type of really rough condition where the combustion is not on time and full will cause the crank to slow down (we are talking nanoseconds). The detection is actually a very complicated algorithm (especially on a high performance manual transmission car). The Feds mandated misfire detection around ’98 and it is actually one of the reason that some foreign cars were no longer sold in the US (Supra …).


[Modified by QuickSilver2002, 12:16 AM 12/28/2003]


[Modified by QuickSilver2002, 12:17 AM 12/28/2003]

 

Wow, interesting stuff -- indeed, I just installed a Racetronix about 1 month ago. I think I had a rough idle prior to the Racetronix though, but that could have been due to any number of things I knew were wrong and fixed later, including a bad tune and bad plugs.

Well, hopefully the misfires are gone with the new filter. Another fellow mentioned he's seen P0300 come up when there's a short in the injector wiring. Frankly I was not looking forward to hunting down a short anytime soon...

:cheers:

 

i changed my fuel filter at 50k miles and it was 50% clogged. After replacing Fuel pressure was more consistant at 59#.