I bought my 64 F-100 about 4 years ago. It looked pretty good, no rust, been repainted, but still red. It has never really run smoothly. I have done a lot of work on her. Brakes, King Pins, rear axle seals, clutch, rebuilt radiator, rebuilt carburetor, master cylinder, regulator, rocker arm assemblies, fuel filter. I did the rockers because when I adjust the valve lash, she seems to run better at least for a few days. I thought it was the original self locking rocker arm adjusters, so I replaces the assemblies and the new rocker arms have adjusters with nuts that lock against the rockers. I don't know how they could be getting out of adjustment when I have locked them in place. Also I just did a compression test and got a pretty even 100psi on all 8 cylinders. I had a friend listen the engine and he thought it might be electrical. I checked the firing order it was correct 15486372. then I started pulling off the spark plug wires to see which cylinder might not be firing. #1, 2, 5, 6 all seemed to make little or no difference, in fact, I can remove all 4 and it runs just the same. without either #3, 4 or 8 it will not start, #7 only makes a small difference. When #1, 2, 5 and 6 are all off and #7 is pulled the it runs much worse. I think it is a small miracle it runs at all on only 3 or 4 cylinders, you can call me crazy, but I would prefer to have all 8 cylinders running.

What can this mean?

I have had the intake manifold off, and it was not obstructed. I had a mechanic set the valve lash for me and adjust the carburetor, and he never mentioned that it might not be running on all cylinders. Not going back to Tony ever again. Does this make sense to any of you? Does it sound familiar?

 

This could be caused by last person who installed timing marks dot-dot instead of 12 pins between marks on rh side engine looking at front.

 

do you think this is a timing issue?
I am a bit week on the electrical side of things. I have not checked the dwell or the timing. I don't own a dwell meter and while I have a timing light, I have not checked it, but when I bought the truck i replaced the points, rotor, distributor cap, spark plug wires, plugs and ignition coil. At that time the mechanic told me he checked the timing, but well I can't count on on Jimmy any more than I can count on Tony.

someone suggested today that bad valve lifters could cause this.

I am, as you can see, grasping at any straw that floats by.

 

It probably just gets dizzy from turning in circles all the time....


But in all seriousness, try a full tune up. Check every single thing you can think of, including the timing marks. Its my understanding that this is a common problem.

 

FOR BETTER RESPONSE... Post this in the y-block forum. Click on forums scroll down to y-blocks post there.

 

Every Y block I have seen have solid lifters. Setting points with feeler gauge at 0.16 and timing at 6* before TDC should make run rite if fuel system is in decent shape.

 

All the cylinders that you state make no change when the plug wire is pulled are in the front of the motor. Does the motor run lean? You can check this by spraying a light mist of carburator cleaner over the carb to see if the RPMs come up. If it is running lean, look for a vacuum leak that can effect all the front cylinders, ie carb base gasket or manifold vacuum line near the front of the intake manifold.

 

maybee a bent push rod happened to me i just hit back striaght with a hammer and put them back in ran great

 

I believe 5starmmd was referring to the valve timing, not spark timing. You'd need to pull the front cover off to see the timing chain and gears, but it's possible that the cam is not turning in proper sync with the crank.

~Steve

 

If he hasn't figured it out in over 3 years then not sure...


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My Y block never ran right either until FTE - the crankshaft dampers on the Y blocks (and other engines) have a rubber bond that deteriorates, and the whole assembly slips off axis. Attempting to time the engine with a light in this case will result in very inaccurate base timing.

One tool that everybody should have who wrenches on old iron is a vacuum gauge. They are inexpensive and super useful for diagnostics and engine tuning. Set the timing using a vacuum gauge with the highest engine vacuum and see what you think. Remove spark plugs from each cylinder and note condition. If they are not firing it will be evident. Excessive fuel soak can ruin spark plugs.

Get yourself a 1950 Motors Manual from eBay and read it. Same with the Ford Truck manual for 1964. If you want to drive a 50 year old pickup you're gonna have to go back a ways in the learning curve. Use the search function here at FTE, and the web and these subjects are well covered on Y blocks. Assume nothing, these are easy to work on and dead simple but sometimes it's the small stuff that causes big problems.