hey guys i took of my heads to replace them for 081 heads,and saw something i didnt like.some pistons had a black coat over them that i can peel off with my nail,wat this?can this be a clue to wat my problem is?that i have posted about?

okay but my engine was rebuilt and only has 5600 miles on it.and i had a really bad lack of power.engine will backfire and miss like crazy,it will basically limp to get rpms.and i change my whole distributor because many posted similiar problems and it was the pickup coil.and nothing,now even my tach jumps while showing engine rpms

Really bad lack of power? Sounds like a bad case of LO3 to me

What is your timing set to? Do you have the EST wire reconnected? I was wondering for about 6 hours last spring why my car was struggling, and it was simply because the damn EST wire was not plugged back in. Set your timing to about 6* advanced, plug that little guy back in, and see what happens.

Your ignition system is probably faulty or you have bad grounds. I would check everything twice and make sure you have ALL of your wires connected, especially the ones on the back of the heads. Make sure they aren't over top of paint or anything non-conductive also. The stock tach is terrible too, so don't rely on it 100%. What exactly do you mean it "jumps while showing engine rpms?" what should it be doing? It's a tach!

i guess all ground's are good,this problem happen from one day to another.the tach worked perfect.then when i change the distributor as its reading it will bounce out of nowhere read right then jump exc.

Sounds like you have your timing set incorrectly if you're saying it worked before you touched the distributor.

My vote is on the ignition module..

i had the problem before i change out the old distributor,but seens i read it can be the pickup coil. so i went and changed the whole distributor for a new one.which brings new module pickup coil and a complete assembly

Did you set the timing correctly? What mods do you have? If I remember correctly you had an LT1 cam put in? IF that is the case 99% of your problems are associated with the stock PROM. Your tune is way off and is dumping fuel into the motor. That is why you have so much carbon build-up since your rebuild.

and more pieces of the puzzle come into play...

If your tach needle is jumping around, you can bet on it.

Actually, that could be just a loose spark plug wire too. I had one come off once, and it did that. Plugged it back in, and it stopped.

I had a hypertech coil that went bad after 8000 miles. I ordered a new summit brand coil, but while I was waiting for it in the mail I borrowed a hypertech coil from my brother's blown up lt1 motor. The tach started bouncing (near the correct rpms). When I got around to puting my new coil on (and converting to TPI w/ the commander 950 at the same time), I couldn't even get it to start. Turned out my #8 plug wire like exploded near the plug. I never noticed because I have those heat sleeve things on my plug wires and the broken wire was laying inside the sleeve. I don't know when that wire broke, but it was running fine with the LT1 coil, just a bouncing tachometer.
So, the bouncing tach could have been from the wire, maybe it was the LT1 coil though? The broken wire explained why I was getting shocked by the distributer during the initial attempts to start it. Seems like it still should have started on 7 cylinders though. I got a new set of wires and it fired right up. hope this experience will help

well i guess i go get my distributor exchanged at autozone.ohh they told the carbon build up towards the rear is due to my tbi adapter mounted in the rear.