valves floating?

[CHARGERSTEVEN]

Well did you try the spray method,didnt see a posting of a new hair cut lol

 

[daytona kid]

Just haven't had a chance. I'm feeling pretty sure it will show fuel starvation is the problem.

 

[69L48Z27]

You would have thought it would have lean popped in your video.

 

[daytona kid]

Good point.

 

[69L48Z27]

It would cool if you could take a GoPro or another camera, stick it on the hood looking straight down the carb. Lots of light so you can see what going on.

 

[daytona kid]

Ok, Did some testing today. Not really sure what to say about the results. You guys tell me. A bud came by and poured gas in the carb as it shuttered. No improvement. He said he could see fuel gushing in from all the squirters as I revved it and as it shuddered. One thing that may have made it act a little different was that I had the air cleaner off and it wouldn't go completely dead. It seemed to run better and stall a little higher with the cleaner off. We also did the timing light test, it stayed blinking during the revs and shuddering.. Someone told me a year ago while installing my fuel cell that the safety foam inside it needed to come out because it would start breaking down and get in the fuel system. I don't think thats the problem but I may take it out soon anyway, it just seems it will be hard to get it out thru the filler hole, fingers crossed.. Another thing that seems to be going on is that it is not cranking as easy as it was a month ago. It acts like it is not getting fire while I have the key turned to crank and then it fires up right as I let off the key. Maybe the 52 year old ignition switch is ready to retire, it was pretty loose and worn feeling anyway. I have a new one ready to go in, just gotta do it. I hate working under the dash.. And I am going to take the vacuum advance hose off of the distributor also as suggested and see what that does, just ran out of time today.

 

[daytona kid]

Another thing that happen during the tests that I forgot about but got to thinking about later was this-> After some of the times it did stall/shudder to a stop I hit the starter immediately and it did what it has done before, it feels and sounds like a couple/few cylinders have no compression while spinning from the starter. In other words I'm back to thinking about valve springs or something going on with the valves. I cannot understand how the cylinder would not have compression after the rev till stall unless valves were sticking open but then it would seem it would backfire some. And how can it fix itself after a few moments and crank and run good, low and mid rpms. As someone mentioned before, could valves floating cause the lifters to lose oil pressure and the valves are just not opening enough to keep it running?

 

[Curiousyellow71]

Never tried it...but you could pull a valve cover off and visibly inspect what's going on when it dies...maybe sacrifice a old one and cut the top off so the mess is less. Not sure if you will see anything...but if its so bad that's its dying and its valve related it may be visible?

Curious as to how good of spark you have 2. Have you pulled a plug out and watched it fire. Put it on the plug wire and look for the spark color.

 

[Slap Stick]

Have you checked to see if the timing chain is off a tooth, etc?

 

[padam]

Have you checked to see if the timing chain is off a tooth, etc?

Spark timing would be way off.

 

[Slap Stick]

If the cam timing is off the ignition timing would show as correct but the valves would be off.

 

[daytona kid]

The motor runs very good from a nice idle up thru the gears till hi rpm, which makes think cam timing should be ok, also I put new chain and gears on and made sure cam timing was good about a year ago... I got a new set of valve springs and hope to put them on this weekend.

 

[padam]

Ok, Did some testing today. Not really sure what to say about the results. You guys tell me. A bud came by and poured gas in the carb as it shuttered. No improvement. He said he could see fuel gushing in from all the squirters as I revved it and as it shuddered. One thing that may have made it act a little different was that I had the air cleaner off and it wouldn't go completely dead. It seemed to run better and stall a little higher with the cleaner off. We also did the timing light test, it stayed blinking during the revs and shuddering.. Someone told me a year ago while installing my fuel cell that the safety foam inside it needed to come out because it would start breaking down and get in the fuel system. I don't think thats the problem but I may take it out soon anyway, it just seems it will be hard to get it out thru the filler hole, fingers crossed.. Another thing that seems to be going on is that it is not cranking as easy as it was a month ago. It acts like it is not getting fire while I have the key turned to crank and then it fires up right as I let off the key. Maybe the 52 year old ignition switch is ready to retire, it was pretty loose and worn feeling anyway. I have a new one ready to go in, just gotta do it. I hate working under the dash.. And I am going to take the vacuum advance hose off of the distributor also as suggested and see what that does, just ran out of time today.

If you decide to take the foam out (mine lasted 20 years) do yourself a favor and take the fill collar off. You will need to clean the inside, and it makes it much easier.

 

[padam]

If the cam timing is off the ignition timing would show as correct but the valves would be off.

I'm thinking the cam drives the distributor, so if the cam is late the ignition timing will be late

 

[padam]

Unless of course it has been adjusted after the chain jumped.

 

[66Satellite47]

Unless of course it has been adjusted after the chain jumped.

Or if it gets installed a tooth off. I had one timing chain set that the dots looked to be lined up, but when I checked the cam CL, it was off, eventually realized it was tooth off, corrected that, the cam timing events were right on. All done on the engine stand, so easy fix. Tossed that timing set. Had a buddy that rebuilt the motor, ran poorly, checked the cam installation, a tooth off, still ran but did weird stuff. Ran good after correcting cam timing. Not the likely the OP's problem, but something to consider.

 

[Slap Stick]

I'm thinking the cam drives the distributor, so if the cam is late the ignition timing will be late

But if you then time the ignition to the timing marks.....

 

[1967coronet]

Check your oil level see if it's over full or smells like fuel.

 

[daytona kid]

Success!! The problem was the valve springs.. Finished swapping them last night and test ran it today. Runs great now!! Thanks for the help guys!!!

 

[PRHeads]

Post #10.

Just sayin.....