Unknown Engine Noise

does it have old gas in that has sat awhile..you may need to run some tank dryer through it as well

its actually on a b2600i so it would have an electric pump.

Ahhhh very good..My bad..I am a special person. LOL

damn.. alabaster is about an hour and a half from me. i'm in south huntsville.

I believe it did sit for a while since it wouldn't run when I bought it. I may just try draining the fuel from the tank and filling it back up with some 93 just to confirm, but I think I'll wait until it's almost empty. Heck, gas is way too expensive to dump out at this point.

I have filled up three or four times since I got it running, though. I would think most of the bad fuel would be gone by now.

Whoa, wait. Check your timing timing and ignition timing. If thats spot on at 6 degrees BTDC, move onto your fuel. I don't think you will have good luck running 93 octane. Go 89 at the most.

You said it has a rebuilt head, did you pull it and get it rebuilt or was it before?

What you may be experiencing is a carbon build up in the combustion chamber. The build up causes your compression ratio to be higher and thus pre-igniting the 87 octance.

Yeah, the 93 didn't make any difference. I'm going to move the timing a little in the morning and see if that helps.

I pulled the head and took it to a machine shop. They decked it and redid the valve seats. He said it checked out fine.

did you kick the hell out of the exhaust?

No, by the time I got home this evening it was already dark and I just didn't feel like crawling under a truck tonight. I'm going to do some kicking tomorrow.

Well, it was definitely a timing issue causing the pinging noise. I got out there early this morning and adjusted the timing. I could have sworn I had it set right the first time, but obviously not. It was probably 30 or 40 degrees off. I couldn't believe it. Not surprisingly, it runs better in every way now.

I appreciate the suggestions.