Thread: 350 help

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I built my first 350 and i'm having problems with backfire through the throttle body. this is a motor out of a 93 k1500. i punched it out .40 over and replaced the stock heads with 96 vortec heads. it has a truck and rv cam also vortec carb. intake adapted for the stock throttle body. the motor is in time and valves are adjusted. could this be a fuel pump problem or something else? i would be grateful for any advise. thanks

could be a lean condition but I'd check valve adjustment first...Dennis

I would double check the timing too... Lead way too advanced will backfire out the top... Way too lean will do the same... As said, recheck the lash too... Might have flattened an exhaust lobe

2cents

Chris

i have checked the timing and adjusted valves again. i even tried new cap and wires thinking it could be jumping spark across wires. i have been going between fuel or ignition problems. what i need to know is if the stock throttle body will fuel this motor.

do a compression check on each cylinder and make sure all your pressures are close and you don't have a problem with an ex. valve.that tb should run that engine as long as the cam was a"computer compatible" camshaft.

ok i have found that it is not getting enough fuel. the pump is working fine. i'm just not getting enough fuel through the injectors. does this mean i need bigger injectors or a bigger regulator.

Possibly larger injectors, but you might want to install a fuel pressure gauge and see what pressure you are running now. Is the camshaft correct for a computer controlled car? No vacuum leaks anywhere????

how do i know if my camshaft is correct my computer. would i be able to run 454 injectors or do i need to chip my computer. this is on a 93 chevy k1500 still has OBD1.

What cam did you put in it?

an elgin rv cam

I looked at their online catalog and see no indication weather they are computer compatible or not. I'd give them a call and check with their tech people.

ok found out it is lack of fuel. the vortec heads are giving the computer readings to cut the fuel back. i found out all i have to do is run bigger injectors and get a custom chip for the computer.