#2 cylinder not burning hot?????

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curbjumper

curbjumper

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JUST REBUILT 73 318 FOR MY DART. HAS A RAW MISS ON #2 CYLINDER. COMPRESSION IS 135ISH RIGHT IN LINE WITH ALL OTHER CYLINDERS. INTAKE AND EXHAUST VALVES ARE WITHIN SPECS OF ALL OTHER CYLINDERS. I HAVE REPLACED INTAKE GASKET FOR POSSIBLE LEAKS. NO DIFFERENCE. DISTRIBUTOR, PLUGS, WIRES, CAP, ROTOR, IGNITION COIL, IGNITION MODULE HAVE ALL BEEN RULED OUT. ANY HELP HERE GUYS????

NO AIR LEAKS, CYLINDER HOLDS AIR WITH NO LEAK DOWN. AM I LOOKING OVER SOMETHING BASIC HERE? DOES NOT SEEM LIKE ITS GETTING FUEL TO BURN.

I WILL PULL INTAKE OFF AND CHECK FOR WARPAGE AND POSSIBLY SWAP WITH ANOTHER:mumum:
 
plug wire, bent push rod, lifter, intake valve stuck, spark plug, bad dist cap, just some ideas.

i know you said you changed the dist and plug wire but i would do that again and change the plug once more before doing a more radical removal.

measure twice, cut once
 
distributor caps are especially sneaky in this regard. a hairline crack can do weird things. very likely on a small block if you jacked up the engine even slightly to put oilpan or headers on etc.
 
Tested resistance on wires, swapped wires on good cylinder to the bad cylinder, no change.... Not a wire

pulled pushrods, measured and micro'd. All within specs. No damage

pulled lifter and measured intake and exhaust valve moving measurements. All within specs

changed plugs with another cylinder and made no difference. Good cylinders were still good and #2 still dead

changed cap with properly running 73 satellite including all the ignition system and made no difference

thanks for the suggestions, this is going to be an issue that someone comes across and says "ah haaaaaa", i remember mine did that once. I cannot figure this thing out. Intake may have crack or warpage. Thats my next step
 
well if the compression is good that rules out rings.
you have ruled out electrical. (i'd still put a brand spankin new dist cap on if you have one. )
i dont think an intake "leak" but maybe... if it was really sucking air or something.
it cant be a cracked head around the valeve seat because the compression checks out.
maybe the intake port is blocked by a piece of gasket? it would still get some air/fuel and would fire though.
unless the valve is stuck closed i dont know bro
 
bad lobe on your cam?

pull the valve cover and crank the engine and watch the rockers for cyl #2, if they are not moving right you will know by looking at the ones next door
 
I'm going with a wiped lobe.

Only a leakdown test knows for sure...
 
Great tips moparlover, but i think i have narrowed it down to a bad valve job.
Not sure yet but i have one valve that appears to not be closing all the way. Valve not cut properly. Going out to pull head off now. Cant wait to be done with this project!!!!!!!
 
Just one more suggestion, put your timing light on the plug wire and check to see if it strobes. It might be a faulty relucter..unless it's a point system.
 
Moparlover, i pulled the head and found valves are not same length meaning someone at previous machine shop (no names mentioned for now, but i would like to) did not cut valves to proper lengths. Would this cause hydraulic lifters to pump up during engine operation and keep valve open? Evrything checks out to be within specs while engine is sitting still or while cranking. If so, i believe this to be the problem. I will keep you posted as i am putting on a set of different heads now.
 
Relucter checks out fine and intake has single pattern with no leaks. Great suggestions though. I'm liking the responses on this forumn already. At least there are some gearheads on here with knowledge. Thanks for all the input everyone!!!!
 
what carb and intake? If the installed heighth isnt right you will have one of two things, coil bind or low seat pressure.Either one could cause problems. One is gonna eventually break stuff and the other is gonna cause a higher rpm miss plus could cause low compression if its not seating on compression stroke. This is where my moneys at. Maybe they cut the seat and didnt shim the spring.
 
Problem solved. Runs like a champ. Valves were not cut properly. Lesson learned. Be careful which machine shop you use. Thanks for everyones input!!!!!

Valve was only hanging open with engine running which is why all mechanical tests came back within specs
 
curbjumper said:
Problem solved. Runs like a champ. Valves were not cut properly. Lesson learned. Be careful which machine shop you use. Thanks for everyones input!!!!!

Valve was only hanging open with engine running which is why all mechanical tests came back within specs
Click to expand...

sounds like i pegged that one
 
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