I just did a cam swap in my 73 comet everything in the motor is stock other then the intake&carb i put a 4bbl on not to long ago, and dual exhaust. I swapped the cam out and now it wont start. Im not a super motor guy i work at a body shop so i i thought i would give my car a little more go seeing as it was all show. Im 75% sure i put the cam in right. 1st on fords you make the 2 little dots on the timing gears point at each other right? Like the cam sprocket dot down and crank straight up 2nd it a comp cam with a 433 valve lift intake and exhaust. heres whats happening it cranks over and wont fire, i have compression 125psi around the board. ive got gas, ive got air, its got spark, ive checked the firing order 5 times its right im sure ( i pulled sparkplug #1 stuck my finger in and cranked the motor till my finger got pushed out, to find #1) now the one thing i wasn't 100% on was setting my rockers i belive there right because i have compression. but 2 people told me differnt things 1. one person just told me to torque them down to about 20footpounds( in the proper order) 2. another told me to lossen them off and twist the push rod until and tighten the bolt untill you cant twist the push rod anymore and then tighten the nut another 1/2 to 3/4 of a turn.
When your #1 plug has compression, is the rotor in the distributor pointing at the post that the #1 plug wire goes to? Later,
You posess the fundamentals of how an engine fires. Good advice on thinking of where the rotor is pointing. I have always gone the first way on adjusting rockers and the second way is how I do chebbies. If all before is correct I would suspect vacuum as in vacuum leak. Happened to me once just like that, intake manifold gasket slipped. Took many nites of tinkering to figure it out. Dan
I know how to find which one is number one on the dist .Im pretty sure its not a vaccuum leak it was running before and i look and no vaccuum leaks. My problem is it doesnt even fire like it doesnt even backfire. nothing and i know i have spark and i know the firing order is right. I put new lifters, new timing chain, water pump and new cam,and new gaskets thats all that is new. other then that it ran like a top before i pulled it into the garage to do the swap I tried the first way of setting the rocker and i had no compression 0 zip natta so i tried the second way and now i have 125psi around the board.
If you've got spark, fuel, the timing gears are lined up as you stated, you didn't mess with anything else and it won't even attempt to fire it either has to be the firing order or the distributor is out of position. Personally, myself, I have been known to drop a distributor in 180 deg.out. In regards to how you have the rockers adjusted, if your heads are stock with the press in rocker studs, they have to be tightened as in your step#1. Step #2 is, as Dan stated, is how we normally do Chevies or once you've converted your heads to adjustable rockers. Something to try before you lose it is to either advance or retard the distributor either way to see if it makes any difference, you might only be out a tooth. Good luck.
yes you are correct... i had the same problem...i knew i had everything correct....then a few guys came by and asked about my rockers....i had the nuts too far down...which left the valves open and wouldnt get compression...you need compression to get fire... so i would back the rocker arm nuts off......just until the rods spin around using your finger tips to turn them.... try to start...if it still wont start....then you might want to call someone...... good luck
Is you new cam for the late model 5.0 (1-3-7-2-6-5-4-8) firing order or the older 302 (1-5-4-2-6-3-7-8) firing order. The distributor rotates CCW and number one cylinder is on the passenger side front (you would be surprised at how many people freak out on that one) Did you install the rotor! Just kidding! Saw that on and episode of American Hot Rod
5.0 HO uses the 137 firing order, Crown Vic and truck 5.0's use the 154 firing order. Which cam did you get? when I got my pertronix I got in a hurry and forgot my rotor button... kinda freaked me out for a minute when it wouldn't start until I realized I had put the rotor in my left hand to turn the key with my right...
Its the 154 and i tried that but the wierd thing to me is that its not even back firing and it has spark and compressing and gas. Im thinking im going to have to rip it apart again.
