you need to do a wet test to see if you have bad rings or if your issue is elsewhere. those are some pretty low numbers.

 

I just realized now that I've got it all put back together I didn't hold the throttle wide open when cranking....is that a test error?? Dang it

 

it might make a bit of a difference. i usually use a screw driver to hold the butterfly's open

 

ok standy by, give me about a half hour or so and I'll do it all over again!

 

holding the throttle open won't make any significant difference.
and its best to do them all the same way.

yes, you have 2 that are ****-poor, but - before you do anything rash, consider how it runs, how many miles, and exactly what problem are you chasing? and the reason i say that is because i've got a honda accord with 260K that has one cylinder at 75 and three at 175. it idles rough, but the damn thing runs ok and gets 35 mpg.

your next test should be a leak down. its where you roll each cylinder up to tdc (valves closed) and pump high pressure shop air into the spark plug hole and listen at 4 key points: oil dip stick (rings). exhaust pipe and throttle body (valves) and radiator cap (head gasket).

good how to: a little long, but informative

 

ok thanks dvaughan, if you don't think it'll make a significant difference than I'm not going to pull all the plugs again. I'm not really chasing anything, I was just doing this out of curiosity to see where I'm at with them. It idles fine, drives fine, doesn't use oil or coolant. I just feel like it could have just a little more power, but dont we all. But its got 146,306 miles on it and All I've done is the plenum fix and fixing every gasket but the head gaskets and rear main. I realize it's probably getting tired... also still the same tranny that rolled off the factory line. This truck hasn't let me down knock on wood. I'll look into the leak down, thank you!

 

You have two cylinders well below spec, and they are on opposite sides of the motor, so, no commonalities there.... you either have bad valves, bad rings, or both..... if the wet test doesn't bring the numbers up significantly, replacing heads will get you back a fair bit of power.

 

I find it unfortunate that you have two low cylinders, but I would think that at only 150k mi you'd still have plenty of life left in it. Besides, unless you've replaced the heads, you could also be looking at a problem with valves.

 

My motor got pretty tired (no power)around 160,000 from lack of maintenance. Had compression numbers around 100 on 3 cylinders, 4,6,and 8. Put some Cermet (not an additive) in the crankcase and could feel the power come back after about 50 miles of driving. 60,000 miles later still have 140 to 165 across the board.
average 12 mpg always loaded. It won't help a bad valve problem, but it worked for me!

 

Interesting. Yeah I've maintained mine very well since the day I bought it, had 84,000 on it when I bought it. I guess things happen though no matter how well you take care of it. I'm not too worried about it yet, when it starts running bad and having troubles then I'll look into options. I'm still going to do the wet test when I can and or the leakdown test.