As the title, my freshly rebuilt engine wont start... It's a Datsun A14 with a 32/36 Weber and electronic distributor.
Short story, I had it running fine for about 30 secs till the fuel ran out of the fuel bowl (due to faulty FPR)
I removed the FPR and now the bastard won't start.
After *much* fiddling I can get it to 'run' but it sounds like it's not running on all cylinders and any adjustment of the distributor makes it piss and fart and backfire out the carburettor. All the spark plugs except for #3 are black as the ace of spades.

I have been thinking it's a timing problem, but I've inserted and timed the distributor as per factory instructions and tried different distributor/leads/coil which as of 5 mins ago has got me thinking that it may be a fuel problem...

How can I tell if it's running too rich or too lean? Being a Weber would the fuel pressure be causing this problem? I'm running an electric fuel pump rated at 2.5-4.5 psi and I've read that Webers need 3.5 psi max... (Keeping in mind I had it running for about 20 secs without the FPR but then the idle kept dropping until it eventually started backfiring out of the carb again)


I'm so fried, at a loss and I think I'm missing something simple so after some fresh perspectives :)


Cheers,
Sam