running like crap.....
Thread Starter
Racer
Joined: Jun 2007
Posts: 291
Likes: 6
From: Delray Beach FL
running like crap.....
My 70 has been running great up till the last week. 350 350HP 4 speed. All original. I went to take it out for a ride and feels like its running or 6 cylinders. I went to check the timing and could net get a signal on the light. I tried up by the dist and light works fine. I decided to grab an old plug wire and go straight from the cap to the plug and does the same thing?? I had the motor out 1,000 miles ago and everything was changed. When I try and drive it or even hit the gas in nutrual I hear it popping out the exhaust. I am going to pull plugs this evening. Any way to test me wires with a meter?
Burning Brakes
Joined: Sep 2010
Posts: 991
Likes: 1
From: Longmont Co
You can test the wires with an ohm meter. Should be no more than 1000 ohms per foot of length, I believe. If it's actually popping slightly through the carb and not the exhaust, then it is probably a broken intake valve spring, exhaust valve rocker arm or pushrod. Assuming that you've eliminated ignition possibilities. Cracked or carbon tracked cap, crossed wire etc. Is it points or HEI?
Drifting
Joined: Jul 2006
Posts: 1,259
Likes: 154
From: Deplorableville Nebraska
Just about the same thing happened to me some time ago. Also a '70 350/350 L46 all original. After I checked everything I could think of, I replaced a good looking cap and rotor and the problem went away.
Burning Brakes
Joined: Sep 2010
Posts: 991
Likes: 1
From: Longmont Co
Jack.
Thread Starter
Racer
Joined: Jun 2007
Posts: 291
Likes: 6
From: Delray Beach FL
just pulled the valve covers and everything looks fine expect one rocker is a but loose. I doubt that is my miss but I will adjust the lash. Going to check the wire one night this week
Burning Brakes
Joined: Sep 2010
Posts: 991
Likes: 1
From: Longmont Co
Do you know which cylinder isn't firing?
Jack.
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Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Change points and the condenser. Chances are the condenser is bad.
P.S. Did you change the coil to a high voltage coil? If so, you are likely burning up the points and condenser. The '70 points ignition system coil feed wire is a resistance wire that is there to limit current to the points. If a non-stock coil is installed...or if the resistance wire is bypassed for a full 12vdc power feed to that coil, it will pour too much current through the system at cruising rpm (and higher).
P.S. Did you change the coil to a high voltage coil? If so, you are likely burning up the points and condenser. The '70 points ignition system coil feed wire is a resistance wire that is there to limit current to the points. If a non-stock coil is installed...or if the resistance wire is bypassed for a full 12vdc power feed to that coil, it will pour too much current through the system at cruising rpm (and higher).
Last edited by 7T1vette; Jan 2, 2012 at 11:02 PM.
Thread Starter
Racer
Joined: Jun 2007
Posts: 291
Likes: 6
From: Delray Beach FL
Everything was replaced with stock original when the car had a frame off about 10 years ago. I wound up spinning a bearing about 2 years ago and pulled the motor and had it redone. At that time I did replace the wires and plugs and the carb was redone by Lars. My dubby who restored the car globbed RTV all over the pan gasket and it broke off and glogged the pump...