chev4by

hey guys i got a 81 chevy short box lowered 6 inches with 96 vorterc heads on a 85 350 block thats bored out and has an xtreme energy cam, this engine was put together 6 months ago and dynos at 400hp so its fun to drive, anywho i was out on some old back roads playing around and all of a sudden my truck started to backfire and pop, so after i got home and let it sit i figured it was a vacumm leak so i went over all the lines and there all good, i got a turbo 400 so i thought i might have cracked that steel line because the road i was driving on was a little rough, but that wasnt the problem,when it was at home i couldnt start it again, i had to play with the timing to get it to run,i keep finding antifreeze on the front of my intake too, so i thought maybe my intake gaskets were leaking so i bought new ones and put them in but that didnt fix it, when i set my timing to where it should be, the engine starts fine but as soon as it put it in gear it starts reving up and down and wants to backfire when i touch the gas, the trucks on propane by the way, but if i advance my timing it runs fine when its in gear and has some touble starting, not good either way lol,so wut do you figure, timing chain jumped or...?

EvansBlue

Timing Chain, maybe. What do you have your valve clearance set to? How does the oil pressure look?

chev4by

the oil pressure is good, not sure about he valve clearance thou

gto8u

don't think it's a timing chain if 6 months old.
looks to be a bad coil. Early collaps of primary circut will cause advanced spark and thus popping in carb....this is usually fine at idle but shows up with higher rpm....also check module if running HEI or electronic ignition. If standard point ignition, check for loose or weak points also. If coil pack, check for leakage...don't forget crank position sensor if used.
what ever the case...sounds like an ignition related problem

chev4by

hmm that could be it, its a HEI mallory distrubtor that is 6 months old, when the timing is set to where it should be it doesnt really want to rev up easy, thanks for the idea thou i'll take a closer peek tomorrow

TransAm Man

That definately sounds like a timing chain. does it have a timing chane, belt, or gears?

rms

weak coil, loose or damaged wiring sounds good. Curious, what did you find?

chev4by

hey sorry guys i havent looked at it in a while, i need it thou next week for work so i better fix it really soon, it has gears by the way