Backfire through carburetor

[CiscoKid]

AS WesN just posted, i had the backfire through the carb issue too on a truck i bought. Removed valve covers started engine and found lifter not moving. Tightened it a bit and restarted. Still not moving. Deduced must be worn cam lobe. I now have a Vortec engine with roller cam.

 

[oldman]

check inside of distributor cap for carbon tracking also check rotor ,bad or cross plug wires ,also check that timing marks are correct.I have seen more that one distributor not installed correctly firing order 18436572

 

[Handy Andy]

One other thing to check that I haven't seen mentioned yet is make sure your 5 and 7 cylinder plug wires are spaced out properly. If I remember correctly, because the location in the firing order is so close on these two cylinders, an induced spark from the 5 wire to the 7 wire could possibly cause the 7 cylinder ignition early and may possibly cause a backfire out he carb... If I have this wrong someone please correct me. I've never dealt with it personally, only read about it.

 

[73c20jim]

5 & 7 wires can cause problem. Do not run them parallel.

 

[Camar068]

5 & 7 wires can cause problem. Do not run them parallel.

nice...learn something new everyday.