1975 L48 running rough causes?
Thread Starter
Instructor
Joined: Oct 2010
Posts: 140
Likes: 0
From: Sunshine Coast Queensland Australia
1975 L48 running rough causes?
Its been winter down here and shes only been out about once a month.
Each time it seems to be running worse and worse.
Starts well but accellerates coarsly and bogs for a second when you gun it ,also seems to be missing ever so slightly.
Was running smooth when i got her but it seems to be progressively getting worse.
I have not touched anything as yet.
any ideas as t where i should start looking, carb, plugs, timing?
Each time it seems to be running worse and worse.
Starts well but accellerates coarsly and bogs for a second when you gun it ,also seems to be missing ever so slightly.
Was running smooth when i got her but it seems to be progressively getting worse.
I have not touched anything as yet.
any ideas as t where i should start looking, carb, plugs, timing?
Drifting
Joined: Sep 2010
Posts: 1,412
Likes: 50
From: Laguna Niguel California
Well, you have to start touching something. Bad gas? Freshen the HEI distributor components. If you still have the Q-jet , check to see if the float is sinking, some cheap ones soak up fuel and sink. Have the plug wires been replaced? Just start freshening up everything - it's a Corvette, you'll love it when it's running right.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Job one is timing - often that progressive worsening comes from a loose distributor cap.
Then, work through the basics starting with ignition then on to the carb. Fuel filter is the first check on the carb.
Then, work through the basics starting with ignition then on to the carb. Fuel filter is the first check on the carb.
Thread Starter
Instructor
Joined: Oct 2010
Posts: 140
Likes: 0
From: Sunshine Coast Queensland Australia
Advanced the timing to about 18 deg btdc and it seems to be running much smoother and better response. i feel i may be able to advance it a little further without pinging.
Still have a big hesitation when i stomp on the gas pedal (vacuum leak) and will sort that out when i change the manifold.
Thanks for the input
Still have a big hesitation when i stomp on the gas pedal (vacuum leak) and will sort that out when i change the manifold.
Thanks for the input
