Dead Cylinder?

[66ford289]

Freshly rebuilt 289. Just got the HEI today and dropped it in. When I fired it up it seems that one or two cylinders don't fire. The headers from these cylinder don't get nearly as hot as the others. I checked spark, the valves don't stick, the lash is at zero (hydraulic liftters), and if I stick my finger over the spark plug hole it will build some compression. What gives? I have a compression gauge but it seems to be misplaced. Could low compression cause a no fire situation? It is getting fuel to because the plug always is wet when I pull it out, although the plug fires? Any advice, is this a burnt valve or something, what would be the symptoms?
(Also my oil pressure seems low, probably need a new pump, but the rockers get oil, could this affect the lifters enough to goof?)

 

[iskwezm]

Are the valves adjusted right?is the came losing a lobe?

 

[66ford289]

i would assume the valves are adjusted right because I set all the valves the same way, and the other cylinders fire just fine. The cam still pushes the valve but should I pull the intake and have a look at the lifter and lobe? Could this be burnt or bent valves by chance? I could use an excuse to get aluminium heads?

 

[iskwezm]

just a suggestion,but check your firing order.

How were your valves adjusted????

Do a compression check,

How many miles?Has it ever ran?

 

[66ford289]

pretty confident on the firing order 15426378..... I adjusted the valves by "feel", I tightened them down until the rocker wouldn't move and then backed off a lil to where the could wiggle a little, very crude I know. I will find my compression gauge and do a check. No miles to speak of, this motor is fresh. It has ran before but never right.

 

[iskwezm]

so was the cam broken in???

 

[302 coupe]

I bet you got some of the plug wires mixed up. Make sure the firing order matches the cam too.

 

[Hardtop68]

I don't know for a 289, but for a '68 302 J-code, Ford calls for tightening the rocker until the push rod cannot be rotated using the fingers. Just keep rotating the push rod continuously while tightening the rocker until you cannot rotate it any more. Then, tighten and additional 3/4 of a turn. This will charge the hydraulic lifters correctly. I've done the same on 289 C3 heads with no problem.

Hope this helps.

Cheers...

 

[iskwezm]

I don't know for a 289, but for a '68 302 J-code, Ford calls for tightening the rocker until the push rod cannot be rotated using the fingers. Just keep rotating the push rod continuously while tightening the rocker until you cannot rotate it any more. Then, tighten and additional 3/4 of a turn. This will charge the hydraulic lifters correctly. I've done the same on 289 C3 heads with no problem.

Hope this helps.

Cheers...

also mention each cylinder should be at TDC

 

[66ford289]

The cam installation called for a 20 minute break in varying between 1800-2200 rpm, which was done. I will double check the cam firing order. Hardtop, I will adjust the valves as you said because I remember hearing about that technique. I'll keep you guys updated.

 

[351carlo]

just to clarify something....

did you tighten all of the rockers at the same time, or did you go around tightening them 1 by 1 while turning the motor over?

something tells me you might have a wiped lobe. Generally a firing order problem would cause a backfire of some sorts when that cylinder did get spark, as the gas would be sitting in the cylinder already.

 

[iskwezm]

something tells me you might have a wiped lobe. .

been there,done thatamnit:

 

[Hardtop68]

You're right iskwezm... I forgot to say that while adjusting each cylinder valves, that particular piston must be at TDC, but in the compression stroke (both valves closed).

That procedure appears in the Ford Shop Manual - so is an "official" way to do it. Remove the distributor cap and watch the distributor lobes and which direction the rotor is pointing to, so to know which cylinder is at COMPRESSION TDC (firing.) Then make permanent marks on the the damper for the next time you adjust the valves.

To make things faster, you can deduct which valves are closed while #1 is at compression TDC - see at your firing order and see which valves are closed - you can adjust more valves at one single position (i.e., if #1 is TDC compression, #6 intake, # 4 exhaust are closed too and so on - just an example.) This way you can do all the valves with only one complete turn to the motor instead of two turns.

When I get my shop manual back, I'll scan that page(s) for you all.

And don't forget to do permanent marks on the damper.

I hope is not a wiped lobe... something tells me that you don't... maybe some rockers are sideways not pushing on the valves?

Cheers...

 

[66ford289]

I adjusted the valves, and that helped it to at least idle. Then I checked my plugs and they were soaked (about half of them). So I wandered on up to my local parts store and bought some plugs in a last desperate attempt before pulling the intake to check the lifters/lobes. Went home tossed em in fired it up, and it ran the same......amnit:

 

[66ford289]

Well, jumped the gun on that last one. This is probably annoying you guys by now. I pulled the intake to check the cam and lifters. There was gas sitting on top of 2 valves ??? The cam shows some signs of wear, what happened when you guys wiped a cam? I have a short and stupid theroy behind the gas on the valves. If the lifters have little or no oil pressure could they collapse and not open allowing the valves to stay shut and fuel to build up?

 

[D.Hearne]

An easier way to check for a wiped lobe is to simply pull the valve covers and watch the rockers while cranking the engine with the starter. If a lobe is wiped the rocker will not open the valve nearly as much as those that are normal. Since you have already pulled the intake, remove each lifter, one by one and inspect their bottoms, a wiped lobe also ruins the lifter bottom.