Rods/lifters not rotating

[calvinator]

I've been slowly bringing a 77 FJ40 2f back to life - I recently re-installed the cam and lifters - reground by the local machine shop. Followed the prescribed break-in procedure with recommended lubes and oils, etc. and 1/2 hour of 2000-2400 varied RPM. Took out for a few joy rides - have about 2 hours total run time so far. The truck runs and sounds excellent - best it's ever been since I bought it. The concern I have is that a couple of the push-rods are not rotating. I've read that this is a very bad sign - indication that the lifters are not rotating and the cam will soon be 'wiped'. I've been advised to just drive it and see what happens; I've also been advised to remove the offending lifters and replace. I've even been advised to remove the cam and lifters and start all over again. And then I was told by a mechanic today that just because the two push-rods are not turning doesn't necessarily mean the lifters below are not rotating. I'm confused and uncertain what to do, so I finally mustered the moxie to turn on this infernal computer-thingie and ask the folks that would know, if anyone does.. I would greatly appreciate any and all observations/advice/suggestions you guys can offer.....

 

[Skreddy]

I would agree that the lifters could be turning without the pushrods. You’d have to take the side cover off to change them anyway, so I’d start there. Remove side cover and crank engine over to see if those lifters spin. If not then pull those lifters and inspect their bases and look down at the cam lobes. If they aren’t spinning it could be too tight or loose of valve lash or lifter bore clearance issues.

 

[calvinator]

Thanks for responding! Sounds like a good place to start - several questions come to mind:
1. Should I remove the distributor to get the side-cover off? (When I started the project, I think I may have taken the distributor out before I removed the side-cover and put the side-cover back on before reinstalling the distributor.) My 70 yr old memory fails me again!.
2. Should I just unplug the coil wire and turn it over with the starter, or would I need to fire it up to be able to clearly discern the lifter rotation?
3. And, if they are not rotating.....?

 

[Skreddy]

I would probably remove distributor, just easier. Since you’ll be spinning it over, there’s no need to mark the distributor unless you think you’d have trouble getting it back in. If so, get it on TDC of cylinder one compression stroke and note where the rotor is pointing.
mid pull all the plugs and unhook the coil wire and crank it over that way. Will spin faster and easier on the starter.

 

[pjohnson]

Can you rotate the pushrod with your fingers?
Maybe they're just stuck and need a nudge to start turning?

 

[Mark Jennings]

Did you have your lifters ground and resurfaced with the cam regrind? They may be concave or worn on one side. The lifters don’t line up directly on the lobe...they are slightly offset against the cam to push the lifer a few degrees of rotation once the lobe reaches TDC against the face of the lifter.

The picture is of an F we got into a while back with unknown mileage...lots of miles actually.... you can see the wear pattern on the cam....the dark areas are non contact...the ‘hammered’ (work hardened) areas are the lobe to lifer contact area.

 

[calvinator]

Yes, I fired it up and I can easily turn the pushrods with my fingers - I dabbed a little white paint on each of the rods which helps to see what's happening with all of them - some are rotating rapidly, others not so much. Of the problem ones, one is actually moving a little bit, (if it wasn't for the paint I would probably think it's frozen), the other one doesn't seem to be moving at all. If the weather gets a little better, (no shop), I'll get out there tomorrow and follow your suggestion to remove the side-cover. Another question comes to mind - when I turn it over with the side-cover off, should I expect and prepare for a lot of oil splash?
Thanks again, gentlemen, for helping this old-timer with his retirement project!

 

[calvinator]

Thanks, Mark - I noticed your reply just after I posted last - I did have the original cam reground and the lifters too. Thanks for the pictures, when I get the side cover off they'll give me something to look for!

 

[calvinator]

Well, I got the side-cover off without having to remove the distributor. Turned engine over by hand to free each lifter - pushed with my finger - all turned freely in their bores. I put a small dot of white paint on the rods and lifters, and a corresponding dot on the block. Unplugged the coil wire and turned it over several times. All the lifters/rods moved except two. I guess I'm screwed? Or should I line up the dots, put the side-cover back on, fire it up and run it awhile, then take the side-cover off and see if the two lifters have moved? I guess what I'm asking is: would higher revs possibly show that the two lifters are actually moving? Or would that just be a waste of time? I'm getting really depressed!

 

[Mark Jennings]

Before you put it back together, pull the pushrod, bump the engine to push the lifter up and see if you can remove...if you can get it out, inspect the bottom of the lifter and look for any scoring or groves. Get a mirror in there and also look at the cam lobe...might be able to get your cell phone camera over the hole and snap a picture.

If all looks good...then put it back together with your painted dots, run it for a while and see if they rotate with some rev’s.

If not, close your eyes, dive it like you stole it, and check the valve clearance in a few thousand miles. If close to where you left it....life is good, if you gained substantial clearance....there’s a new cam in your future.

If you can rotate the lifters with your finger...there should be no issue.

 

[calvinator]

Well, finally got some decent weather to work on the beast - everything looked good. Put the lifter cover back on - went for a 50 mile joy ride (drove it like I stole it) out and back on a paved road with a few hills. Noticed right away that the engine running a little rough, not bad but noticeable. Pulled strong up the hills, no lack of power. Stopped 25 miles out, idled down nicely. Tried the dollar-bill trick at the tailpipe, no sucking. Turned around, drove home, still not running smoothly. Idled down in the driveway - dollar bill trick again - intermittent sucking! Actually, I don't really know if there's anything to the dollar bill method - some people swear by it as an indicator of valve/lifter/cam problems, others think it's a gimmick. What do you guys think? Regardless, what causes the sucking/popping at the tail-pipe? Is it normal, or is it the dreaded wiping of a cam lobe or worn lifter? Or could it be a timing issue? I have a Pertronix ignition, timed to the BB. Vacuum gauge reads 18 at 650 rpm. Slight vibration in the needle. Forgot to mention earlier - when I had the cam and lifters reground they also completely reconditioned the head, so I would hope I don't have valve problems. Any suggestions or comments?

 

[Mark Jennings]

Sounds like you covered most of the bases.

Popping at idle or acceleration is a lean burn condition...carb issues...
Popping, backfire on decel is an exhaust leak.

However, a bad/burned exhaust valve will give you a rough idle and some popping in the exhaust.

Did you try the age old ‘read your spark plug’ methods...get yourself a new set of plugs...take her out to a nice long stretch of back road...install the new plugs...do a couple of full throttle runs...turn it off then pull the plugs and compare to the many Google depictions of lean, rich, oil issues...

It’s an old fashion weekend drag racer tuning trick but it will give you some indication if there is a combustion problem.

When you do this, keep in mind if you are using ethanol laced fuel...10% ethanol will give a slight lean burn indication. And that may be part of the issue. May require a main jet size increase...depending in the fuel used.

 

[calvinator]

Thanks, Mark, I really appreciate your experience on this -- it does appear that the break-in of the cam may have failed (if the rough idle and the 'dollar-bill trick' are the result), but before I try again (or sell out) I'd like to exhaust all other possibilities, (pardon the pun), however remote. I tried measuring rocker travel with a dial indicator but there was hardly any difference at all. I'm going to try the spark plug analysis tomorrow and see what that shows. Thanks for the ethanol tip - I think Chevron's 'supreme' has no ethanol - is it O.K. to burn that in the FJ? It's more expensive, but I'm not on the highway at all, not putting a lot of miles on, just hoping to chug around in the bush looking for fishing holes anyway -- too old to roar around in a cloud of dust like the young bucks in the pick-up ads on T.V.

 

[firestopper]

A vacuum gauge will also tell you about the overall heath of your engine. Use a good manifold vacuum source and plug whatever you pulled to access the vacuum source.
Take the time to understand the link below.

Quick Tech: How to Read a Vacuum Gauge to Pinpoint Engine Problems - OnAllCylinders

A vacuum gauge is an invaluable resource for tracking down engine issues. The key is understanding what your gauge is trying to tell you. We’ve put together this quick-guide to …

www.onallcylinders.com

 

[Skreddy]

Do you have headers? If so, spray some water from a squirt bottle on the header tubes for the cylinders in question; if you’ve wiped a lobe the water won’t boil off as fast on those. But, if it’s just starting to go, you won’t notice yet. Rocker travel also won’t tell you much if it’s just starting but lash increasing will.

 

[Mark Jennings]

Also run a compression check....all cylinders should be close. Don’t worry about the pressure....just as long as they’re close. Also, what was it doing or....what led you to think a cam regrind was in order.

I think Chevron Supreme has up to 15% ethanol...look on the pump next time you fill up...it’ll say something like “up to 15% ethanol”.

 

[calvinator]

A vacuum gauge will also tell you about the overall heath of your engine. Use a good manifold vacuum source and plug whatever you pulled to access the vacuum source.
Take the time to understand the link below.

Quick Tech: How to Read a Vacuum Gauge to Pinpoint Engine Problems - OnAllCylinders

A vacuum gauge is an invaluable resource for tracking down engine issues. The key is understanding what your gauge is trying to tell you. We’ve put together this quick-guide to …

www.onallcylinders.com

Thanks for the vacuum info - I'll have to pick up a new gauge and study up.

 

[calvinator]

Also run a compression check....all cylinders should be close. Don’t worry about the pressure....just as long as they’re close. Also, what was it doing or....what led you to think a cam regrind was in order.

I think Chevron Supreme has up to 15% ethanol...look on the pump next time you fill up...it’ll say something like “up to 15% ethanol”.

Thanks, Mark - it was doing pretty much the same thing before the regrind - when I pulled the cam one lobe was beat up and its corresponding lifter looked like someone was going at it with a chisel.
I did a compression test; #1-132, #2-130, #3-142, #4-138, #5-147, #6-145.
Appreciate the heads-up on Chevron - I'll have to do some research on fuel - things may be different here in Canada.

 

[Mark Jennings]

Canada...love the beer....didn’t pick that up in initial conversation!

Do you remember what cylinder the rough lobe was in? Is it the same cylinder as the one where the lifter isn’t turning? A single beat lode is usually indication of some sort of previous failure in the valve train...maybe a broken rocker, spring, etc.. even a bad valve adjustment, if left to long could hammer an individual lobe.

Did you run a piece of emery in the lifter bores before assembly? Maybe a score or burr?