Engine Intermittent Spark, no start

Mar 25, 2014
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#1
Hey everyone it's been a while. About lost all patience with my 78. So life's been busy for the last couple of years so the cars have been sitting around and not run much. Well I wanted to get my 78 running enough to move it around or drive it for a bit. It has not had a gas cap on it for a long time so the fuel tank pretty much was 50/50 water fuel... It would start right and run but very poorly and it would idle all day with the choke on. So I pulled the tank cleaned it out, cleaned the carb very well put it back on and it barely ran and was popping very loud out of the exhaust and shooting fire. It seemed like too much fuel so I got out and looked and sure enough after shutting it off fuel was dripping out of the secondary boosters. Took the needle and seat out cleaned it put it back in and it barely wanted to run at all. I started messing with float level after that figuring taking the needle out messed the adjustment up. It got to the point where the car wouldnt want to start at all. No fuel, a lot of fuel, it would crank all day and not start. I started chasing spark, put the timing light on and noticed it would only fire every few rotations. Used a spark tester to confirm. Long story short ive been pulling my hair out with this thing. It has a new cap, rotor, condenser, coil, and points which are adjusted to .020. It will spark about 4 times then nothing for a few rotations than back to sparking a few times. Watching the points they consistently seem to spark. Ive given the coil direct 12v and replaced the signal wire from distributor to coil. Every now and i mean very rarely it will start for maybe 5-10 seconds. Played with the timing and nothing helped, its set at about 8* right now

I'm at a total loss, how did a fuel issue turn into a spark problem after cleaning the water out?

The engine did kind of "explode" along the way... while adjusting the floats a lot of fuel was spilled and it popped out of the carb and light a few rags on fire which led to what i assume vapor build up under the valve cover to explode. It blew the valve cover right off the bolts... Regardless it is having the sames problems now as it did before that.

It's a 1973 302 with the stock points ignition. The carb is a Holley 4160

I'm pretty much out of options so any Ideas will help, Thanks!
 
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LILCBRA

10 Year Member
Dec 6, 2005
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#2
After pulling my hair out over a very similar problem years ago, I found that I had the ground cable come loose for whatever reason - my suggestion would be chase grounds. Otherwise I'm at a loss, same as you. Maybe your plug wires have gone bad???? I mean if you have spark at the points every time but only intermittently at the plug, that's about the only connection between the 2 as long as the new cap and rotor is good. Check grounds first as it shouldn't cost you anything but time and go from there. Let us know what you come up with - good luck!!
 
Mar 25, 2014
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#3
Went out the other night and didnt change anything but it had spark everytime at the tester. The spark looks weak at the plug though. Checked grounds today, everything seems fine. Used jumper cables both from negative side to engine block and tried it. No sign of life. I give the carb three pumps but after so long of cranking it smells like there's a fuel leak. The plugs are dry though. I need a break from this thing!
 
Mar 5, 2019
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#4
If the valve cover blew off, check the oil for gas contamination. A couple of gals of gas in the crankcase could be problematic for starting.
Points suck maybe a pertronix in in your future
 
Mar 25, 2014
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#5
It sorta had the issue before the valve cover blew off, then again it all started after it was flooded so ill have to check. Ive looked at a new ignition system and will probably go that route soon. I haven't touched the car in a while but I am planning on a compression test next. Thanks for the ideas!