ok, here is the problem. i have had this problem for a while now. I was consistanly running 13.0 at 103. My best was 12.80 at 106. In a previous trip to the dragstrip, my top end has dropped considerably. I am now only running 13.3 at 94.94 mph. what is going on? while going down the strip i can feel the car being held back. it feels like it is running out of gas at higher rpm. how can i be sure that is the problem and how can i fix it? also, the plugs seem to be way to LEAN. I currently have 72s in the front of my 750 carb and 84s in the back. Why would i be so lean? running out of gas or not enough gas? what should i try?

at the corvette challenge, yesterday, the car was running like crap. i somehow managed to win two rounds, that was cool, but im worried about the car breaking because of this problem. are my timeslips. Normally, if i have a 60' of 1.95 or quicker, i get a twelve second run. not the case this time. any suggestions?

RT: .603 60': 1.880 330': 5.376 1/8: 8.401 mph: 80.22 1000': 11.074 1320': 13.391 mph:94.94


RT: .537 60': 1.883 330': 5.385 1/8': 8.417 mph:79.86
1000': 11.096 1320': 13.399 mph: 97.50

:crazy: :confused: :rolleyes:


[Modified by Vetteboy, 6:28 AM 9/24/2001]

 

My first thought was a problem w/ fuel delivery, but it's also possible that your ignition is having a problem.
I always start w/ the easy things- are your floats properly adjusted? Are your secondaries opening all the way? Have you checked/changed your fuel filter(s)? If all's good there I'd check fuel lines for kinks or blockage. If that was OK I'd check fuel pump for output.
If it all checked out I'd move on to a carb rebuild, unless you've done that since the problem started.
It does sound like a fuel shortage but the wet plugs throw a twist into this- are you sure they're wet w/ gas or could it be oil related deposits? If you're sure it's gas & the above suggestions don't help, maybe it's time to test your ignition system. A weak coil could possibly be the culprit. I'm tired & I'm sorry if my thoughts seem a bit unorganized. Hopefully this helps- maybe somebody else has some ideas....Good luck.

 

bet its something simple like:
coil, something in cold air intake?, fuel pump, filters, gas tank vent/pressure,
vacume secondarys not opening?
looks like its affecting the last 1/8 mile mostly. which makes me think its something ignition or fuel related, something getting weak as you get further into the run.
my $.02
RJ

 

sorry guys. i typed that the plugs were rich. that is wrong, the plugs are way to lean. not rich. i will start with the basics. any other suggestions. and how would i even check the line for blocks?

 

The most likely blockage would be at the fuel filter itself. You could also look at the "sock" inside the gas tank to make sure it's not gunked up w/ debris. Anything blocking flow inside the fuel line is pretty unlikely but, if everything else checks out, you could disconnect the soft line back by the gas tank & also disconnect the line before the fuel filter- then shoot some air through to make sure it's clear. I still think it's the filter, fuel pump, or carb.

 

ahhh, lean huh, that makes more sense.
you can rule out the ignition now. gotta be fuel related.
if your using the stock in the carb/bowl filters(porous metal type) they are spring loaded to allow fuel to bypass when clogged, but that could still be your problem. Its a good idea to change filters once and awhile anyway, so might as well do it.
check all rubber fuel lines for cracks,it could be sucking air in at high RPMs (I'm taking for granted that your using a mechanical pump on the block).
it would be tough to test a mech. fuel pump for a problem your having half way down the strip. so if it was me I'd just replace it and the rubber line to it while your there.
remember there may be rubber lines at the fuel tank too..
highly unlikely its the metal fuel line, but I would check it for damage. it might have gotten dinged and or restricted (be sure to check around any areas where work was done recently)
If all else fails, throw money at it :crazy:

Les is saying the same thing "fuel" . looks like I just repeated the same things. :flag :flag


[Modified by ol,RJ, 3:20 AM 9/25/2001]

 

thanks for all the suggestions. im gonna get to solving this problem. i will let you know if i figure it out (ever). thanks everybody :D