EvilCartman

iTrader: (1)

The car must have 1st day jitters or something, didn't run worth a crap During the 1st burnout after a quick 1-2 shift then bumping it to 3rd, the engine started breaking up bad and banging out the exhaust losing power. Cleared out the engine with a quick rev, seemed fine. Lights came down, launched ok then just fell on it's face banging through the exhaust again before the 1-2 shift. Even while crusing down the track, seemed like any amount of throttle other than maintaining a constant speed would cause it to start running like crap. Second pass was pretty much the same so I loaded up and watched a friend run for the rest of the night. One guy in our little group said he saw flames shoot out the exhaust on the driver's side pipe.

The thing that gets me is, I haven't made any changes to the car since before last November when the car was constantly in the 11's. I've driven the car around town with a short blast here and there without any running problems too.

Here's a quick list of what I'm running

MSD pro billet dizzy locked at 38*
MSD 6AL box
MSD blaster 2 coil
1/2 inch aluminum fuel line from tank to regulator then a single -6 line to the carb's dual feed line.
Mallory comp pump 250 gph
BG5000 fuel filter before the pump
Fuel pressure, 6.5 psi at the regulator engine running
Mighty Demon 750
Float level should be fine

Got a month to figure this out before I get to go again.

Stevo

iTrader: (45)

New gas?

AlkyIROC

Dirty fuel filter?

1320_Guy

iTrader: (3)

Sounds like my situation, GL figuring it out.

EvilCartman

iTrader: (1)

Had a nearly empty tank, put 5 gallons of new fuel in before heading to the track, haven't checked the filter yet. Going to mess with it tonight and start checking things over. Also going to borrow another 6AL box from a buddy to see if that might be the culprit if all the fuel stuff checks out.

xpndbl3

iTrader: (5)

what was the fuel pressure going down the track? and if you don't have a guage mounted inside that cowl.....now would be a good time to buy one

ross

Try a new set of plugs. You may also may have valve springs going away.

tommyboy

One thing to look at as well is the alternator. Make sure it is charging and also check your electric fans ( I assume you have them ) and any other device that draws current. If you have low voltage at an msd box it will cause misfires and make sure your ground off of your msd box is connected to the battery and not a chassis ground.

EvilCartman

iTrader: (1)

Ok, as of now here's what I've checked.

Fuel filter = looked good, replaced anyway.
Carburetor bowl inlet screens = perfectly clean.
Timed how long to fill up a 1 gallon gas can = 32 seconds (hummm)

Not sure of the pressure going down the track, no under cowl gauge. Looked down at the volt gauge after the burnout, 14v and it's a fairly new alternator. MSD box main power and ground are hooked to the battery. Electric fan may have been on but I'm sure it's been on in the heat of summer (90-100 degree weather)

Last year it would start to slightly break up after the 8th mile but went away after raising the float level slightly to where it is now. The way it's running now, I was only able to muster a mid 15 second run on and off the throttle plus just cruising to the finish. Freakin embarrassing! haha Going to put the street tires back on tonight and take it for a spin tomorrow to see if it acts up again.

xpndbl3

iTrader: (5)

fuel pressure guage....

before beating on it and running it lean and popping something.

EvilCartman

iTrader: (1)

Pulled a plug at the track after idling back on the return road, looked pretty black They're not fresh plugs, same ones I used for most of last year I think. I'll see about figuring some way to get a pressure gauge where I can watch it and pick up a set of plugs.

On another couple notes, took apart the fuel filter and it had plenty of junk stuck in the pleat valleys. Also, was doing some reading on MSD's site. The way I've had the pickup wires from the distributor routed I guess was a no no. They were bundled with the 2 wires going to the coil plus a couple others. They're suppose to be at least 6 inches apart if running parallel. In the off chance that could be it, wonder why it hadn't done anything in the past 4 years it's been wired that way; moved them anyway to make it right.