Posted by It was the firing order. on January 27, 1999 at 12:01:47:
In Reply to: Re: Firing order posted by TParker on January 25, 1999 at 11:45:07:
#1 and #5 were switched. It must have been that way for a while, because it never ran this smooth. Now I can get to work tuning it. Any advice on smoothing out the starts? I'm getting black smoke now, and untill it warms up it feels like it is "skipping".
'73 302 V8
: #1 is the one closest to the battery going back to the fire wall is 2,3&4, thats the pasanger side, on the drivers side closest to the front is the #5 going back to the firewall is 6,7&8 hope that helps. Also the distributor cap should be marked with the #1 and the order is counter clockwise 1-5-4-2-6-3-7-8.
: : I must be making this hard on myself.
: : I used the "one at a time" method when changing the plugs and wires, but that doesen't mean they were right to begin with.
: : I appreciate the firing order info. Now, how are the cylinders numbered? I want to make sure I get this info from the Maverick board.
: : May seem like a stupid question, but my last mav was a straight 6, and the only other engine I work on is a 2 cyl bike.
: : : Route the #7 and #8 plug wires as far away from each other as possible (not side by side). This will ensure there is no "crossfire" between these consecutively firing cylinders! (1-5-4-2-6-3-7-8, and YES I do know it by heart!!! ;-)
: : : : A '73 Maverick 302 uses a Motorcraft BRF-42 plug, although other brands may use a different part number. These should be easy to cross-reference in the book at the parts store. Are you SURE you have the correct firing order. Check it again, it shouldn't be backfiring...
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: : : : : I decided to start over again from the beginning and retrace my steps. Spark plugs are cheap so I went to buy 6 more(had 2 new). I had just bought a straight replacement for the one in my hand last time. It never occured to me to do what I always do in carpentry NEVER trust the last worker's measurements. The ones I bought today (all 8) are autolite 45's.
: : : : : The ones in the engine now are 46's. I hope that this has been my problem all along. It seems the last mechanic used what he had and then decreased the gap. I'll post an update on Monday.
: : : : : 1973 302 V8 2bbl. Any further comments on the plug situation? T.L. what do you think? Could this be the culprit(s)?
: : : : : BTW, I did cap off the EGR valve and its related vacuum hose.Removing the valve is a little more involved that I can do right now. I did not notice any change, but I'm hoping the plug change will allow me to move on to better things.