Smoke under the hood?? HELP Please!

[pain995]

Ok here's the deal the 69 barracuda is running smooth as silk.  But what is happenning is every so often after I start it up and I drive it around a bit.  Then I shut her down for say 5 minutes or so I'll go to start it and it won't start right away and when I turn the key off I'll get a SWOOSH sound and a cloud of smoke from under the hood.  Almost like a backfire through the carb but with alot of smoke.  Then the car will start up and run like a champ.  It's really embarrasing especially when you get people checking the car out when you go to start it and drive off and it happens.  Someone said the timing may be off and it is firing when the intake valve is open.  But you'd think if the timing was off it wouldn't run as smooth as it does.  Its a 318 with a Holley 650 carb and air gap intake.  My fear is that it may catch fire under the hood so I'm almost afraid to continue to take her out on the weekends.  Any help and advice is appreciated.

[Chryco Psycho]

your timing is probably close , the problem soulds like cobustion or just compression spinning the engine backwards as you relase the starter which could be caused if you are not getting proper spark while cranking the engine , the start circiut bypasses the Ballast so it will not be that but you could have a power problem in the ign switch while cranking & not be turning the ign on   

[MEK-Dangerfield]

Too add to what Chryco said, I had a similar problem when I first bought my car. It turned out the ballast resistor was about twice the value it should have been, so it was only semi-bad. It took me a while to figure that one out.  With the key in the "on" position, what voltage do you measure on the "+" side of the coil? It should be around 10 volts.


  Mike

[pain995]

Thanks for the advice guys. 

your timing is probably close

So Chryco are you saying if my timing was slighly off it could cause this?  I'll also check ignition switch etc. 

Mekrunner  Thanks I'll dig out the mutimeter and run a check on that also.  Your saying it should be around 10 volts?  Is there a high/low value that I should be looking for?  Like if it measures at a volt or 2 in either direction should I replace.

Thanks again   PS:Anyone know any good mopar mechanics in the Lehigh valley area of PA???

[MEK-Dangerfield]

Mekrunner  Thanks I'll dig out the mutimeter and run a check on that also.  Your saying it should be around 10 volts?  Is there a high/low value that I should be looking for?  Like if it measures at a volt or 2 in either direction should I replace.
[/u]

When I was having my trouble, I was getting something like 8.8 volts on the "+" side of the coil. Starting it was never all that easy unless it was real warm outside. 


  Mike

[Chryco Psycho]

no the timing is not the problem
 low side is about 8 v at the coil if it is less change the ballast & yes they can increase resisitance & drop voltage over time without burning out so replacing them from time to time is not a bad idea either

[JCWCuda]

It's also a good idea to carry a spare Ballast resistor with ya 

[pain995]

Thanks guys at least I have a good starting point.  I'll take your advice and go ahead and just replace the ballast resistor.   Thanks again