Hello, im having a serious problem trying to get my 1972 datsun 240z started. All the plugs are recieving a spark and fuel is reaching the carbs without any problem. The engine will just turn over until it lets out a massive backfire in which it actually blew my muffler in two, however, it only does this occasionally. Does anyone know what the problem may be?

Are you sure the timing is right? It sounds like you're getting spark but at the wrong time.

it could be the timing cuz i did replace the distributor rotar, cap, and new wires. how would i go about adjusting the timing. I looked it up quickly in a chiltons manual but left me confused =(

Was it running properly before replacing the cap? Could it be 180 degrees off? Are you sure you replaced the wires properly?

i matched it up with the firing order in the chiltons manual, and i wasnt able to turn the rotar 180* so im assuming thats all correct

and no it has not run for about a year... i went through just about everything in the carbs and ignition and i just dont know...

hmmm im lost... i still cant figure it out