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Author Topic:   Missing AGAIN!!
Rook78
Member
posted August 16, 2004 09:30 AM
can you describe the miss in more detail?
is the miss a rumble ( marble in a can) like motor is not running on all cylinders or is it like a sputter/hesitation?


Rook78
Member
posted August 16, 2004 10:33 AM
Float level or fuel supply problem? Dirty air bleeds? What's your fuel pressure at idle? What about at higher rpm?
Just sticking 80 jets in a carb won't cure a lean condition of the bowl runs dry....

Hope that gives fuel for thought...

KP


Rook78
Member
posted August 16, 2004 12:20 PM
Rook78, one other area you might want to consider is your grounding of your distributor. We had a real bad miss in our one mod and it popped and cracked everywhere around the track. We use a MSD box with a GM HEI setup and had the ground wire going to the intake. We changed the ground straight back to the battery and the miss dissappeared. Did the same in my street stock (stock HEI only) where I spliced in a ground wire to the battery and eliminated a miss. Hope this helps.


Rook78
Member
posted August 17, 2004 08:18 AM
12.3 volts is plenty. i'd guess it's a carb problem from the symptoms of "misses
unloaded, and starts after 3000 rpm", especially if you can get up to 6500 rpm.
from my experience, if you had an ignition problem no way you'd get to 6500rpm if the problem started below 3000 rpm.


BrianW
Member
posted August 17, 2004 10:34 AM
quote:
Originally posted by Rook78:
I have a 12V battery and it puts out 12.8 from the battery. By the time I get to the dist. lead it is 12.3 is this enough, or should I go to a higher voltage battery?

That's a lot of voltage drop - 1/2 volt drop is considerable - I'd be looking at a bad connection - pay attention to the frame ground - check that it's to clean metal on both sides - from the battery cable to the starter solenoid should be 2 ga cable or better - resistnace is only in the tenths of ohms / 1000' - so a 20' section from the back to the front is going to have nearly 0 resistance, the wire between the solenoid and ignition switch should be 12 ga and also should have nearly no resistance in the short distance. If you're dropping more than .05 volt between the battery and ignition module you've got something wrong...



smayo964
Member
posted August 17, 2004 11:51 AM
As for the voltage drop, I agree with BrianW. The minimal size wire we run on our mods for grounds and main power is 12ga. We've also doubled up on the grounds by not relying on the chassis ground and all components are ground back to the battery "with" the chassis ground. It only takes a clouple additional lengths of wires and has eliminated a whole worth of electrical headaches. Also, it might be just me, but I feel we've kept our amperage better in the battery throughout the course of the night without recharging since we've added the better grounding.


Rook78
Member
posted August 17, 2004 12:15 PM
Hey Rook78, no problem. We added from the block to the negative battery post the same guage as the one from the battery to solenoid. Also, all the lights are grounded through to this additional wire. The MSD box, tach, and distributor are grounded through a 10ga wire back to the battery post. Here's the kicker, if you are running a stock HEI, the middle plug on going into the cap is a ground wire for your coil. I have either spliced that wire, or added a wire to the distibutor hold down bolt, and run them back to the negative post on the battery with the tach, etc. Basically, I tried to isolate each circuit, even if only 1 or 2, and eliminate any chassis grounding.

For you question on fuel, if you have a tank of bad gas with water, etc., your car will run like junk. We had that happen once where it would idle, but no hit a lick when you put your foot to it.

Rook78
Member
posted August 17, 2004 03:14 PM
We run a #10 Bare copper solid wire from the point where the battery bolts to the frame along the frame to the motor plate. We use adel clamps and pop rivet them to the chassis about every 12 inches. This gives you a good ground source all along the chassis and it also gives you a stiff fixture to cable tie other stuff to that would run along the frame rail.


Rook78
Member
posted August 18, 2004 07:19 AM
change the spark plugs...


Rook78
Member
posted August 19, 2004 02:39 PM
The lower the resistance the better.

Be sure when checking plug wires that you are using comparable lengths, as most of those measure from 40 ohms per foot (Moroso Blue Max) to 80 ohms per foot (MSD) and on up for cheaper wires. If you're measuring the #8 wire versus #1 you're going to get different readings based on length.

Are those "LiveWires" the ones that come with grounding straps for each wire?

Rook78
Member
posted August 24, 2004 11:41 AM
No, they do not. They were 95.00 though. They seem to have helped, along with the other stuff I did to the car, I turned 6800 on Saturday, the highest this little 355 has ever seen.


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