I havent had my car running in a while, and i just recently rebuilt the carb and tried to get it running. The car initially starts up but after running a bit it started sputtering and spitting out of the carb. After a couple times of trying to get it running, i gave up (it wouldnt start.) Im sure i blew my power valve again, so im going to rebuild it again and add spectre power valve saver (some cheap insurance from summit) and try it again. My question is why is it backfiring out the carb? It may be timing, but how do i time it if i cant get it to stay running? im pretty sure the wires are correct and both plugs and wires are new... Also i am running straight manifolds (long story), so would the lack of back pressure be the cause of the back firing? HELP!

 

Lack of full exaust will not cause problems.

What is it spitting out the carb, fuel or flame? If fuel, might have trash in inlet needles causing flooding.

If flame, could be timing. Or valvetrain problem. Has any distributor or valvetrain work been done? If distributor, rotate distributor slightly CW or CCW to see if it helps. Can't be too far off since it at least starts. If valvetrain, make sure valves are adjusted properly. If overadjusted, the valves might not be closing once the oil pumps up the lifters.

I've also seen broken springs or rocker arms cause spitting.

 

before the car was down, it ran completely fine. Since then i havent done anything to the distributor or valve train. The carb is actually spitting fuel, but one time it backfired and it was a ball of fire. I have also changed the plugs and wires, and im pretty sure the wires are ok... but eitherway if it was missing, it still wouldnt account for it backfiring like that right? Ill rebuild the carb and mess with the timing i guess. Thanks for the reply.

I noticed your name, do you have a 71 RS? If so you got any pics?

-Chris

 

If it's spitting fuel, and you have a Holley (I presume you do since you mentioned power valve), take care of that 1st. Try cleaning the inlet needles:

http://web.camaross.com/forums/showthread.php?t=403798

Pics of my RS on my sad little website:

http://www.geocities.com/angel71rs/

 

Do what angel said. Another thing you can do to set initial timing is spin your engine over to the desired timing IE something like 12 or 14 degrees as indicated on the balancer/pointer then you line up the rotor on the distributor to #1 The rotor should be close to #1 before you do this. ALSO make sure none of your wires are crossed. Check your float levels as well, if they are too high then it would cough fuel, load up, and die. (Ive had this happen) You can do a really really rough setting by taking the float bowl off turning it upside down and set the needle so the float is about halfway up. You will need to reset it while the car is running but it wont be too high this way. You might want to also shoot some carb cleaner/compressed air down the air bleeds as well.

 

when i had it back fire and flames and fuel came out it was just the wires being in the wrong spot (little brother thought it would be funny)