Distributor Module. Mechanics, Answer Away Please!?

Question

Hey... on my car (1972 Chevelle, everything is connected perfectly fine (vacuum hoses, hoses, belts, timing, valves adjusted perfectly, new oil, filter, fuel filter, fuel lines etc...) Anyway, on my car, we had a mechanic come and check it out at my house. We started it, and it gets really close to starting but won't go. It practically does start but doesn't go. Fresh fuel, adjusted carb and everything works fine. It is getting fuel. And we checked for spark with new plugs... it is getting spark and it is aligned perfectly. So, when we turn it over, it won't start all the way and if someone holds the throttle wide open while it's turning over and spraying fuel in there and it backfired like crazy; however, it does sound really close to going and the timing is correct (checked with the timing light and not 180 degrees off). So, this guy said that the HEI MSD Distributor is a crappy one to have. And that the module is probably bad and not emitting a spark at the right time. Whadya think?

Answer 1

recheck valve clearance, if the valves are too tight

they will pump up when it fires

Answer 2

anytime you get a backfire out of the carb like your getting it's a timing issue or crossed plug wires, if the ignition module was bad you wouldn't get any spark at all.

Answer 3

Sounds like your plug wires are crossed , Check your car manual and see if your plug wires are in the right place 1-4 or 1-6 or 1-8 depending on how many cylinders your car has.

Answer 4

msd makes good products. for your vehicle alot better than factory parts. well i once had a 67 impala with a 327. and i had what sounds like the same problem. well think about it. what does the module do. it doesn't time the spark it just provides it right.?. well it is either out of time. or you have you valves too tight. you really should get a different mechanic if he doesn't know what thew function of a module is. pull out your number 1 spark plug put your engine on top dead center on the compression stroke you know when you hear and feel that lil puff of air out the plug hole. then make sure you lined up on you crank and pull your disrtibutor cap off and make sure it is pointing in the right direction. also you failed to mention if you just built this engine or just did work to it. well i'll cover all areas i can. check timing again, check plug wire location do you have any crossed, firing order on a small block chevy is 18435672 big block i don't know by heart. check you valve adjustment then check you valve timing is timing chain installed correctly. with the cam at 6 o clock and crank at 12?  that should help you out. and by the by. find another mechanic that car is to precious to have a da working on it.

Answer 5

First I would check my valve timing, then ignition timing, Hydraulic lifters need to be pumped up and does take a long time of cranking to pump them up. Best to loosen til slight clearance. Is compression been checked this will tell you if the lifters are keeping the valves open.You will have no compression. If you have a timing chain that is sloppy or jumped time will also cause incorrect compression. If you put gas in the carb. and it backfires then you have open valves or incorrect ignition timing. Also recheck the fireing order and rotation direction of the spark plug wires. Recheck you ign. timing by removing #1 spark plug and hold your finger to the spark plug hole while someone taps the starter to get it up to top dead center also allign the timing marks and check that the ign. rotor is pointing to # 1 spark plug wire on the dist. cap. Hope this helps you.  good day and good luck