When it comes to electronic isues or Carbs I'm not the mechanics mechanic;but I try and use common sense.For the past 6 months,my car has not been all that reliable on restarts,meaning after the initial start-up from cold and the engine running for a few minutes,I can crank it,pump the gas & it just won't start.In desperation ,to get it out of the way of whatever place I am in,a small shot of ether brings it right to life!This made me think that I had a coil issue & just wasn't getting a hot enough spark to the plugs.Currently I'm using the$6.00/ea. electronic/modern plugs in the car as to only have to change them once per season (as the gas in Ct. is just loaded with everything but gas.)But I will put 5 gals. of the leaded 110 oct. in at every tankful to help offset those issues.So last night I fired the car up with the old coil,let it run 3 minutes shut it off & as usual,it wouldn't start.Next I rigged up this Petronix 40K volt coil temporarily to see if it made a difference.Again ,I had to pump the gas 3 times to get it to start & by the way bypass the balast resistor(Per the Petronix instructions--which I wasn't too hot about)and the car seemed to run pretty much the same except I saw a 200RPM increase in the Tach!Now I know they also tell you to increase the plug gap,but I just wanted to try it out 1st.By the way,I also checked my plugs prior to any of this & on half the plug was pure white while the other 1/2 was a dark gray.Now,same thing ---in order to get it to start,I always have to pump the pedal 3 times to get it to fire-up.I really don't feel this coil made a difference unless it will show its merrit when I am ocassionally "excercising" my car!So,I really not sure which way to go.I had the carbs rebuilt by Craig Woodruff a couple years ago.And yes, both the outer carbs throttle valves are fully closed during idle as to not let too much air in.I'm stumped!!---I Appreciate your help.
1967 427/400 HP STARTING ISSUES
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Re: 1967 427/400 HP STARTING ISSUES
I assume it starts right up after 1 throttle depression when cold.....To release choke and get initial accel pump of gas...
If you start it from cold ... run it for a few seconds... shut it off... will it immediately restart?
If its hot... shut it off... will it immediately restart?
A few things to check.....
Are the carbs possibly dripping into the manifold when you shut it off and flooding the engine? (Floats too high)
Intake manifold or carb leak... loose bolts etc?
Could the starter be drawing too much current after its warmed from the initial start, causing the voltage to be too low? Check to see the voltage at the coil during starting..... from cold and after warming... should be the same... close to 12v....when the ballast resistor is not in the circuit (during the start cycle)
Do you have a bad ground?
Are the battery cables in good shape?
Does the battery hold a good charge?
Have you tried using a jumper battery (and good cables) after warming engine to see the response at starting?
Are you losing compression after warming up??- Top
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Re: 1967 427/400 HP STARTING ISSUES
Battery voltage, nothing on, should be about 12.8V
During cold cranking voltage at coil should be 11+ volts
If after starter is hot, voltage drops significantly during cranking cycle, say to 8V you probably have a problem with the battery or connections or starter. Make sure the ground cable lug on block is good (no paint)
There will be a voltage drop after cranking when the ballast resistor is in the circuit to about 8 volts. This is normal- Top
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Re: 1967 427/400 HP STARTING ISSUES
This can happen when the car sits for a few minutes. That is why I asked if it will start immediately after shutting it off... as in killed the engine at a stop sign..... or if the problem is immediate and it won't start without effort.- Top
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Re: 1967 427/400 HP STARTING ISSUES
To Steve,Wayne & ecyone who offered me help.THANKYOU VERY MUCH!!Problem solved.I went through the list of everyting that you guys mentioned---no carb drip,bat.ok,compression ok,no vac leaks,but when I retighteded the connections @the coil,balast resistor,grounds,& expecially that green shut off switch @ the battery----something happened----now after she's warmed-up.turn the key---no pedal pumping---just fires right up--THANKYOU!- Top
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Re: 1967 427/400 HP STARTING ISSUES
Glad I could help.....
Tough to troubleshoot from afar.......- Top
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