mikes74gmc

First time blogging so If I posted in the wrong place please let me know. OK driving down freeway 70mph. I get 3 backfires through the carb and it dies towed. I have replaced the dist plugs wire set initial tdc Adjusted valves all look ok springs etc run compression tests #2 and # 4 no compression all the others ok oh rebuilt Edlebrook 650 mix is 1 1/2 out to start fuel ok. OK here's the problem. Cranks good tries to start I get that, oh it's going to start but then it dies. I am thinking I should readjust loosened valves while I adjust while cranking. Does anybody have any thoughts on what happen on the freeway? Also, anything else you can think of I should do I am going to look up how to do a leak-down test after I do valves if not fixed.

Well, I just checked the coil and pick up coil. Going out to put the cap back on and see what I get. I was getting a weak spark so I hope this helps. If not the valve covers come off and I will check compression in 8 first. Thanks for the tip. Mike

New hope this is the right place. Driving down the freeway at 70 mph running great then 3 backfires through carb dies tow home. What I have done. Rebuild Edelbrock 65o set float levels air fuel 1 1/2 turns out squirts fuel ok fuel pump and pressure ok timing set to TDC on compression stroke rotor pointing at #1. Power to HEI elect and choke with 1/8th inch open cold normal when running idle 900 rpm crank to start rotate dist clock and counterclockwise. New battery, plugs, wires, fuel filter. cleaned cap and rotor. spark and fuel ok The engine cranks OK tries to start then dies during crank it is normal then lugs down to almost stops for a sec then cranks ok again tries to start catches then dies. I am going to pull the valve covers and check it out. I built this engine and the whole truck AND I NEED HELP! Any ideas on what happened and why the fix does not work?