Dead Cylinder Below About 1500 rpm's
How do you know it is in #6? 130 psig in all cylinders sounds great. Strange that someone assembled the engine with the wrong size piston rings. Any idea how that happened? The outer cylinders tend to run leaner, so would be first to suffer "lean mis-fire". Could also be the spark wire or something in the distributor cap. People have found many caps w/ the tower circle off center. Slant Six Dan has posted the best PN to buy.
I know it is number 6 because when I remove the H-tension lead from the plug end, while idling, the engine does NOT react in any way. But, when each of the other wires are removed (one by one of course), the engine noticeably stumbles. But, if I set the fast idle to over (approx.) 1500, then remove No.6 lead, the engine reacts. Also, when removing each lead from corresponding plug, they all give healthy sparks - when held close to cyl. head, and that includes No.6, so that kind of tells me the cap, rotor and H.T. leads are okay. I tried several plugs in No.6 and no effect and also swapped with one of the other plugs, and, swapped No. 6 lead with No.1 - and still no power from No.6.
I then removed the valve cover - - and everything looks good. I remembered installing good 318 springs 5 years ago and, the lashes all in spec.
A 'broken' spring would tend to allow cyl. to make power at idle - but lose power when revving higher (acting as a weak spring). At least this is what happened with a friend's LT1 years ago.
Bigger concern (with broken spring) would be the risk of 'dropping' a valve into cylinder. I should also add that I am using the Mopar electronic setup (with a HONDA module) and it's been flawless for last 14 years. I checked the pickup to reluctor gaps and all between .008 and .010" - and a reminder again that healthy spark at 800 and at 1500 - yet NO 'combustion' at 800.
Car was parked from Dec.01 thru April 10th. I installed battery, filled carb, tapped pedal twice and it started in two seconds. I did this from passenger side so never worked the accelerator until few minutes on fast idle. It then idled smooth and I insured it on the 11th. and drove off and on for about 30 miles.
It was 3 days later when I parked it in garage to service oil, filter and tranny. I also checked plugs, wires, cap and rotor (and, for reasons unknown) when I started the car again - after the servicing, it immediately did not sound right. That's why I am here now.
