Serious wiring difficulty!

[kaherc]

82 Mercruiser (Chevy)5.0L 305. Trying to figure out how to wire up the starter and alternator and have it work so that batts get charged as well. Installed a new alternator with an internal regulator where the old was external reg. Also, have put in an electronic ignition conversion and coil. Used to be points. New coil #is 40011.<br />Attempted to wire it all up. Engine cranks great but wont start. Backfires big time thru carb. I looked at the manual and cant figure that out either. Feeling overwhelmed. Have been fixing this thing for a few months now. Bout ready to give up, take it out and sink test it. <br />Could really use some help. Anyone in the Tampa/Clearwater, Fla area?<br /><br />Thanks Korie<br />Figures, I can fix million dollar jet engines and cant figure this stuff out! Isnt that just silly!

 

[DangerDan]

Re: Serious wiring difficulty!

if it backfires through the carb it's likey that you have spark. Did you remove the distributor and replace it with another or was this a conversion kit? Are you sure your not 180 deg. off on your distributor? To check make sure your rotor points to the #1 wire on the comp. stroke.

 

[kaherc]

Re: Serious wiring difficulty!

Its a conversion kit. It was so simple to put on I dont suspect that I messed it up. How can I tell if on its compression stroke? And if theres spark, why wouldnt it start? Im so pissed off at this point. Its tough to not see the end result after all the work Ive done.

 

[kaherc]

Re: Serious wiring difficulty!

Does anyone have a diagram of how the wiring is supposed to be? If so include new 3 wire alternator.

 

[DangerDan]

Re: Serious wiring difficulty!

it's not your alternator,,, well not yet. You will feel comp. on your #1 plug hole if it's the comp. stroke. Did you remove the dist?

 

[tommays]

Re: Serious wiring difficulty!

http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012808 <br /><br />i dont have one but this is some and if you post in the I/O forum you may get more info<br /><br /><br />tommays

 

[OBJ]

Re: Serious wiring difficulty!

Don't know much about the kit you installed Korie, but you should be able to roll the engine to line up the timing marks to #1 cylinder and look at the distributor rotor to determine if the set up of the kit is right.

 

[eboylan3]

Re: Serious wiring difficulty!

Korie, you ask "And if theres spark, why wouldnt it start?"<br /><br />It's not just spark, it's correctly timed spark that starts and runs your engine. You must have spark near or slightly after top dead center (i.e., the very end) of the engine's compression stroke in order for the engine to fire. The reason it's backfiring through the carburetor is that the spark is occurring while an intake valve is open. That lights off the fuel/air mixture in the cylinder and the flame runs back through the open valve up the intake manifold and up & out the carburetor. Unless the timing chain or timing gears are defective in some way, a carburetor backfire can only occur if the engine's spark timing is incorrect or there is a sticking intake valve. That's why everyone wants you to get the compression stroke and spark event in sync. You can't easily adjust top dead center, so you've got to adjust the distributor's position in or on the engine to achieve the desired spark timing. The library should have a car repair manual or two that will cover the process of getting your distributor in the ballpark. Good luck.