My 1972 ford 390 motor wont start
 

when trying to start the motor all it dose is backfires really loud. it appears that it is getting fule to only the back plugs. i repaced the timing chain and that made no diffrence. the distriputer is new and installed correctly... My question is what could cause fule not to reach the sparkplugs? the motor was running fine and than on the freeway lost power and started back fireing liike it is currently doing no matter what i do..

I'd suspect your new dist either has had some type of premature failure, or more likely, has slipped and rotated. Could even be 180 deg out if a "goof" got made. Nothing personal, but I did that once by mistake and engine wouldn't start and I got a few bangs out the exhaust. The timing may be off so far, those back two cylinders arn't even being lit up and so look wet.

Any more info you can share that might make this clearer?

ps: another possibility is your dist drive gear pin sheared. It can grab a bit here and there during cranking and the odd "bang" will occur, but it won't start. Easy to check ....does your oil pressure come up when you crank it (or light go out)?

With the timing gears and distributor being new there is room for error so go back and double check the TDC is not 180º out or just wrong. If you don't find anything there check the firing order. Still good, pull the valve covers, spark plugs and dizzy cap. Turn it over slowly by hand and watch for signs of illness @ the dizzy post and valve trains. If the timing set/dizzy/firing order are in order then you may have a huge vac leak or serious valve related issues. IMO

lets gets some info on this as Argess mentioned...how was it running before the timing gear set and the Dizzy Replacement ?

If it was back firing then ? you might have had a burnt exhaust valve, and if it was sneezing out the carb..that would indicate a bad intake valve or timing being advanced to far, Or by slack in the chain and jumoing a tooth..
Your either going to get enough fuel to stay running at idle or not run at all...Or running and stalling but NO back fire !

As mentioned Bring #1 up on TDC..you can check that by pulling #1 plug out and putting your finger over the plug hole..and when it blows your finger off..its close to TDC... At that point find your #1 plug wire at the Dizzy and mark it with chalk on the dizzy so you remember where it is..Pull the dizzy cap and see if the rotor is pointing at the terminal on the cap... If not.. Pull the distributor and move it until it points to that terminal..

With the angle at which the dizzy gears are cut..It will look like your going to be off a touch lining it up.. Just looking at it buy sight and dropping the Distributor in..Take it a tooth off and watch it when you drop it back in...and you'll see that when the distributor gear mesh's with the cam gear..it will slide into place.. And damn sure dont drop the Oil pump shaft in the pan !! :)

Have fun !!

Why not just move the plug wires in the cap to line up with the rotor, rather than screwing around and pulling the dist.?

Ditto Spagettios

Yeah That sounds like all he needs is a bunch of damn wires all over !!Chit !:-blah

I hope to hell he is not to stupid to figure out the firing order starting from anywhere on the cap. ;) If he is, he should even have the hood open. :rolleyes:

Well from things I have seen in the past....a bunch of wires scare the livin hell out of some ! including so called Mechanics !! :-RTFM

Well, I was a teenager during an era when "Hot Rodder" meant you made things work even if the engineers couldn't.

But MY God, it's only eight frickin' wires and the other end is hooked to a spark plug in a numbered hole and the frickin' firing order is on the intake manifold. :rolleyes: