Missing on a cylinder

[Matt167]

Last week before I put the E brake cables on my Rambler, the engine ( 196 OHV ) was running great. after me and My dad went out to test the car after the cables were put in, the engine wasn't firing on 1 cylinder, we figured the brakes being done was enough for the day so we picked up, I'm going back to working on the car on monday.. I'm thinking it's just a spark plug, I replaced them b4 but, I used Champions in the factory heat range.. originals were cold fouled. when I had checked the vac b4, it held 16 HG steady warmed up, had a tiny pop when cold so it does have a slight valve issue when it's cold.. when it starts now, it fires right up, but you have to rev it up slow in park once or twice, otherwise it will die when you try to move it, it did not do that b4.. I have the choke adjusted open all the time. any ideas?

[65ny]

Sticky valve maybe?? Feed it a can of Marvel Mystery Oil (in the fuel and oil both) and see if it reacts. This may sound like "snake oil" but i'ts worth a try.

[Matt167]

Yes, use AC's, and check the ones you take out to see if they are black or not. Are your plug wires ok ? And, that valve might just be getting a little worse.

ps: Are you running H18Y plugs ? Gap, .035

yes, I put in the Factory H18Y.. book says .033-.037 gap, there factory at .035 so I'm good

[Matt167]

Not sure on the Mystery oil, but you get the engine all the way warmed up, and up the rpm's, and pour water slowly through the carb, and if the valves are just carboned up, this will break the carbon free.

I'll do that, was thinking of doing that when I got back, also thinking about trans fluid to make them reseat if there not seating

[Matt167]

Sticky valve maybe?? Feed it a can of Marvel Mystery Oil (in the fuel and oil both) and see if it reacts. This may sound like "snake oil" but i'ts worth a try.

I didn't think you could run marvle mystery oil in gasoline? thought it was only for crankcases or diesel??

[65ny]

I didn't think you could run marvle mystery oil in gasoline? thought it was only for crankcases or diesel??

check this link out: This stuff has been around longer than dirt.

http://www.marvelmysteryoil.com/

[Matt167]

Well, I went out today, pulled the plugs, found all but #5 are burning perfect, #5 is not firing and was gas fouled.. because I had no new plugs, I swapped #5 and #6 and fired the car up, seemed to still be missing. I pulled #6 to find the plug was cleaned off and was burning. #5 was now gas fouled ( was a good plug in #6 ) so I knew somthing was wrong. got out my compression tester and tested cyl #5... 25 PSI, just to make sure my tester was in check, I checked cyl #1 and got 150 PSI.. I know it's ither rings or valves. going to go out Friday and get a leak down tester to check which it is.

[nitrowarrior]

Double check your valve springs. It was running great and all of a sudden, it misses on a cylinder. It's worth a look.

[Matt167]

Double check your valve springs. It was running great and all of a sudden, it misses on a cylinder. It's worth a look.

I think it's a stuck valve. it ran awsome 1 day, and was missing on a cylinder the next.. leak down test will tell for sure. gonna pull the valve cover too tho..

[jerry clayton]

you don't need the leak down---you already know its bad---take it apart and fix it

[Matt167]

you don't need the leak down---you already know its bad---take it apart and fix it

I know it's got a compression leak somewhere, but don't know where, need to pinpoint it to rings or valves. I know it needs fixed.

[Matt167]

I tried making a leak down tester out of 1 of the plugs I changed out of it, after I cleaned out the porcelin, I epoxied ( quick steel putty epoxy ) a 1/4" coiled air hose 3/8" end inside of it and sealed it up nice... didn't work out as planned as the coils cought on all the hoses and plug wires. was too much of a hassle so I tossed it.. I have a rubber tip for my air gun somewhere, I'll have to find it and try that.

[Matt167]

Well, I bought the leakdown tester but never had to use it... I went out the other day to move the car and it mysteriously started to run better after I started it and it warmed up a little.. checked the compression on the cylinder that got 25# and it was getting 125# and it was firing, which to me said it was a sticky valve because that is the only thing that could fix itself but... after it cooled off, it stuck again. My dad told me not to do anything to it and to change the spark plugs w/ 1 step hotter and see if it ran better and just to stick to that plan, as was what he told me to do before I diagnosed a low compression issue.. he came down and I still hadn't changed the plugs ( they were burning true and looked perfect, except #5 the dropped cylinder ) cause I saw no point, it was not the problem.. well we changed the plugs, and it did nothing, no supprises to me there. then we were changing condensor and points, coil, plug wire, trying an electric fuel pump ect... I tried to tell him it was a valve issue and he wouldn't listen... finally after he did a power balance test by pulling plug wires, he determined #5 was dead.. after verafing it had ignition, he pulled the valve cover and just as I said, a valve issue. the valve stuck open and let the push rod fall out of the rocker.. put it back togther, turned it over and it stuck again and did the same thing, so he put it back togther, I turned it over whail he held the rocker down, it broke loose quickly and now runs great again.