Author Topic: 1967 428PI Ignition Problem  (Read 41 times)

Offline kkupec02

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1967 428PI Ignition Problem
« on: November 26, 2024, 09:44:42 PM »
New problem with my 428PI. I recently put in a rebuilt date coded distributor with points and condenser replacing my after market electronic ignition. I also put in a rebuilt correct ignition coil. I don't think it has been even 100 miles since it was done. I went to a cars and coffee about 50 miles away 3 weeks ago. The car ran fine on the way there. On the way home, the car started running horribly and backfiring from the front carburetor. It got worse as we nursed it home. At idle in the garage, it is a rhythmic front carburetor pop every 2 seconds or so. I replaced all plugs and plug wires, reconnected the old ignition coil, changed the points and condenser and checked for vacuum leaks all to no avail. Any ideas as I am running out?
1967 GT500 Built 1/26/67 #817
1967 Corvette Roadster

Offline midlife

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Re: 1967 428PI Ignition Problem
« Reply #1 on: November 26, 2024, 10:03:41 PM »
Sounds somewhat like timing went off; have you checked that?  Could be the condenser is bad.
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Offline Bob Gaines

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Re: 1967 428PI Ignition Problem
« Reply #2 on: November 26, 2024, 10:09:53 PM »
New problem with my 428PI. I recently put in a rebuilt date coded distributor with points and condenser replacing my after market electronic ignition. I also put in a rebuilt correct ignition coil. I don't think it has been even 100 miles since it was done. I went to a cars and coffee about 50 miles away 3 weeks ago. The car ran fine on the way there. On the way home, the car started running horribly and backfiring from the front carburetor. It got worse as we nursed it home. At idle in the garage, it is a rhythmic front carburetor pop every 2 seconds or so. I replaced all plugs and plug wires, reconnected the old ignition coil, changed the points and condenser and checked for vacuum leaks all to no avail. Any ideas as I am running out?
Check the float level . They may have gotten stuck. His were stuck way low. I would start with giving the adjusting screw on top of each bowl a good wrap with a screwdriver handle to maybe knock it/them loose. I had a friend with somewhat similar symptoms on his 67 GT500 and that was his problem. You may have to take needle and seats out to inspect and clean before installing and setting the float level.
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