Vacuum...16" Hg? That's too low for a decent running engine.....unless you have one of those useless "***** Thumper" type cams.

What does the vacuum gauge tell you? And, yank a plug or two...what are they telling you?

Definitely check for vacuum leaks, and yer timing, too

 

indeed...the primary reason I also got timing tape. I was able to raise the vacuum by advancing the timing, but just didn't trust the harmonic balancer. I'll re-time it, maybe tomorrow

if a PO put in a cam, it's real mild. I suspect stock

 

Torque converter is showing age.

 

Keep an eye on those pulley bolts, and make sure none back out. Good call on the loosened bolt being the chicken and the vibration being the egg, there privateer!

 

Compression within 20psi on all cylinders? Carbon buildup on pistons?

 

16" steady manifold vacuum could be OK, depending. Subtract about 1" from the "normal" spec for every 1500' of elevation above sea level. Since he's in the Arid Zone A he may well be pretty high.

 

Dumb question.........Numberdummy states that there is an internally balanced 460 and an externally balanced 460.......You stated that the balancer you got is for an '80 and up..........Are you POSITVE that you installed the correct one?

 

Great question...no, I am not positive. As far as I can tell, there's no difference between the balancers for externally and internally balanced engines. The difference is in the spacer that's between the harmonic balancer and the engine. The 79 (and up) has the tomahawk spacer, while the 78 (and before) has a round spacer.

Other posters have reported that 460 balancers are neutrally balanced, and many parts houses show that the balancer fits all years. So there's a bit of confusion on "which" balancer. The one I bought looks and feels exactly the same as the one I took off, even though it's spec'd for 80-95. And, it's also the same as is on my 77.

So...I'm not positive, as there seems to be confusion as to which is correct, and how to tell them apart.

But anyway, the new balancer is the same as the old balancer, and the symptoms are no better and no worse. When I get around to putting my pants on, I'll go look for another cause (and verify the timing)

How does one check the condition of the torque converter?

We're pretty low here in Yuma-about 200' I think. So I'll be looking to get the vacuum back up to 17

I'll check at least a few plugs and report back. If it's not too hot, I'll do a full compression test. It was about 100 degrees yesterday.

 

Ok, pulled a couple plugs out, and they didn't look bad-at least not to me. Interesting, however, that they were tan on one side, and white on the other side. By the way, these are platinum plugs, so the electrode looks funny:




Number 5 - tan side



Number 5 - night and day

So I pulled a couple more:





These looked similar to the first, so I pulled them all:



All the plugs looked pretty much the same. Nothing stuck out as immediately obvious

Once all the plugs were out, I blocked open the throttle and ran a compression test:


The pressure rose Immediately to 120ish, and topped-out between 150 and 160:



Pressures within 7% and nothing extremely low or high

The plugs don't have that many miles on them, but are probably a couple years old. Since they're all out, I'll probably go get new ones now. Copper ones...

 

Great compression test... and yes I'd change the plugs if they are a few years old. Standard NGK units are always good in my opinion. The sporadic idle sounds ignition related for sure and plugs are a good place to start.

 

The tan color on one side isn't too bad....a tad bit fat, but overall, very good....it shows what side of the plug gets the fuel/fire. #6 plug doesn't look that good (lean), unless the tan color is on the opposite side of the picture. Compression is good all around

Nothing to gain with platinum plugs except a few more dollars out of yer pocket. The copper ones - Motorcraft, Autolite are better for our vehicles.

 

X3 on some copper plugs, although it looks like you don't need us to tell you that...
My first choice would be Motorcraft, but I wouldn't be averse to NGKs. And for anyone having header clearance troubles, Bosch makes copper plugs, and like the platinums, they are a tad shorter than a Motorcraft or a Splitfire - at least the plugs for the E7TE 5.0/302 heads. Not that anyone asked...

 

Colors are normal for blended gas. Good compression.

A neighbor had me install E3 plugs in his 77 f150 with a 460 swap. The thing hated those plugs. Backfired and missed like crazy. Had me replace them with Bosch Platinums and it ran much better. I would have stuck with copper myself because it is supposed to be more conductive. Platinum and Iridium are used to extend the interval between plug changes. This was especially important on vehicles that use waste spark coil packs like the 4.0l Rangers. Otherwise the life of the plug is cut short.

When you have it all back together, fill an old Windex or other spray bottle with water. With the engine running spray a mist on your plug wires. It is helpful to do this in gear and someone standing on the brake to load the engine. You may have an occasional miss through the insulation that will show up with help. Also helps to do this in lower light so you can see the spark, say evening.

 

Problem solved!!!!

Replaced the plugs with MotorCraft ASF42C, gapped at 0.044". Not much difference. Perhaps a little better.



Broke out the timimg light and attacked the new harmonic balancer. It was a few degrees off from the old balancer. Adjusted the timing up to about 14 BTDC. Better, but still not quite right.


While inside the cab, revving the engine, I heard it-a hissing sound when revving. A little re-checking of the vacuum lines revealed the big cap on the TEE had split. Giant sucking sound!!!

Replaced the cap, and all is very well:

 

Nicely done. Thanks fer gettin' back to us with yer fix