1989 4.9L -> Dead cylinder afer new lifter install.

[Sevensecondsuv]

My F-150 had some nasty lifter knock going, so I spent most of today swapping the lifters out for some new ones. Sure enough, the intake lifter on cyl #6 was pretty seized up and took about 30 minutes just to extract it from its bore. After that everything went pretty smoothly and it's now got 12 new Sealed Power lifters in it. The pushrods and rocker arms looked just about perfect so I didn't replace those. I torqued everything to spec, and threw a new cap and rotor and new spark plugs and wires on it while I was at it.

I got it all back together; fired it up, and quickly figured out which vaccuum lines I forgot to re-connect Once I got that all sorted out, I noticed it now has a dead cylinder. The lifter knock is gone and the valvetrain sounds nice and smooth.

I pulled plug wires while it was running and isolated the dead cylinder to be #5. I pulled the plug out and it had gas all over it - further confirmation that it's not firing. The rest of the plugs looked good. I've checked and re-checked the firing order, which is 1-5-3-6-2-4. I've checked the spark plug for #5 (and all the other cylinders too) holding it against the intake while the engine's running and it definately has spark. I also tried swapping the old ignition parts back on and it didn't make a difference. So #5 has spark and fuel (gas on the plug) but it's definately not firing. I'm out of ideas. Anyone else have any?

 

[Sevensecondsuv]

Well I took it all apart again and found the #5 intake pushrod sitting about 3" above the rocker arm!!!

I put it back in place and threw everything back together. The new lifters and new ignition system make for a lively six! It's now back to it's old tankish self!! Just the way I like it!