On the way home Sat. nite after racing,car became sluggish than started missing,idleing rough. Next morning fired it up and both back header tubes(7,8) were cold. Changed plugs on those two,had to drop passenger side header to change that plug,changed cap,rotor button,and tightened up #6'srocker arm since it been rattling. Now runs like ****,overly rich exhaust,still back two header tubes aren't as hot as the others. and sometimes 6,7 were dropping plus i have a header leak. Pulled the easy to get to plug out and its wet with gas,so put another plug in the plugwire and laid it to the side and turned the motor over and had a nice strong looking spark. Now I'm dumbfounded. Coil going bad? Ignition module?
Car info.91 RS 305 with 92 350TA TPIw/computer and memcal,#24 injectors,Fuel pressure set at 35psi,MSD6,MSD coil,headers,world product heads,1.6roller tip rockers,zz4 cam.

 

have you checked for spark to the plug on the dead cylinders? are you sure you didn't over tighten the rocker? run c ylinder balance test, do compression test

 

I don't think rocker is overly tight. Don't have a compression gauge. I've pulled the plugs out and they a drenched in gas. swapped the plugs and they fire fine. Changed injectors and MAP sensor. Still same problem different cylinders cutting out.

 

HB,

When you remove all the plugs, spin the engine over for several revs to help clear out any exces fuel. You don't want the fuel in your oil, anyway. Try clean, dry plugs and fire up again. Check the plug wire routing on the suspect cylinders, and try to get your hands on a compression tester as Ed suggested so that you can remove the possibility of a stuck valve or other compression problem.

 

I wonder if you have broken valve springs, what type of ignition (HEI?) Try checking the plug wiresand watch them in the dark to see if they are arching to the head.

 

this sounds like a dillie of a pickle. i would find a way to get a compresion gauge and check for compresion. i mean it sounds like u got spark, fuel and air. so it would seem logical to check compresion. take it to a mechanic or most auto parts stores have a loan a tool programe. good luck man