67 200 valve miss? Or ignition maybe fuel

Hello i like this site its about the sixes.The last mustang show in my area i went to had 82 mustangs and only one 60s with the six cylinder. I think they are becoming more rare than a 289.

Ok so no more rambling i have had the same miss since i got the mustang.She runs good except every couple seconds she studers. Sometimes once sometimes 3-4 times.Then sometimes when warmed up it wants to miss real bad at idle.Things i have done to repair. Replaced Holley 1940 for autolite 1100.new vacuum advance and thanks to a member of this site a free electronic ignition. New fuel system.Timing is set at 12deg and the advance is working.The timing light i have is not blinking everytime and before i pull the head i just want to make sure i didnt miss something. Also the dollar bill trick on the exhaust pipe results in the dollar getting sucked in and out . Not shure what that means i just saw my dad do it a few times.And all my cylinders have the same compression except the third one it is 110 fifteen points lower than the rest.

Howdy John:

What year? What trans? I'm betting you already checked the easy stuff- vacuum leak, possible tricky ones like vacuum hoses. Also check plugs and plug wires- again, you've probably done already. Since it changes depending on choke and idle speed I'd be taking a close look at the choke functions. Also check to verify that your timing mark is at top dead center.

Have you checked your rocker arms for wear and/or slow oiling? Might be worth a look.

Hope that helps, keep it coming.

Adios, David

the "dollar bill trick" tells you what the air is doing. if you had a normal miss, the extra volume would push the bill out further than normal exhaust flow would. in your case however, since the bill is being sucked back into the pipe it indicates that there is a vacuum being created in the pipe, and that means an exhaust valve is leaking.

Trust me i have bean over every component of the engine in the outside but i have not pulled it apart. I posted this 3 times and all responses are same valve issue. So the head is comeing off today im waiting on brakes anyways.

Ok compression is 120 128 110 120 130 120 so
C4 tranny
Ok so im taking the head off worried about the piece that has possibly broke off the valve and wondering if there is a way to check the rings. If there are no apparent problems. Like filling with a liquid and measuring leakdown and what fluid. As i will be changing the oil.

i am going to say with your numbers, you have leaking valves.

When you get the valve cover off, take a look at your push rods. I did have a similar issue - it was plain to see that my pushrods were bent, along with my rocker shaft being packed with grungy old oil (no lube!). I Suspect that turning it over after being stuck for a while caused this. I was able to drive it about 1000 miles like this until I realized something weren't quite right...



Good luck, post up some pics of what you find!

- Perry

So far everyone of the valve seals is broken also how do i ad pictures

There's an 'Upload attachment' tab down below. Click on 'Browse', find the image on your phone/computer and click 'Add the file'.

- Perry

if you swear its not a valve then next would be valve spring but more likely a lifter, then cam. variable answers of course a bowed pushrod, bent rocker, sticky valve, beat valve seat(or damaged),rings . cyl's. a wrong piston, rings, leaky plughole