3 causes of detonation- how to eliminate each?

[fireguy12117]

i am really sorry for posting this yet again since there are others in the forum, but i really am just at my wits end here and seriously contemplating selling the 93.

so far as i can tell detonation is brought on by elevated cylinder temps.

carbon build up
lean fuel
engine timing is off

on a remanufactured OHV block would it matter if if was a 95 long block versus a 93 long block for how the heads flow in and out of the cylinders? i have a reman'ed, so i have to imagine with less then 2k miles i am not dealing with a carbon build up issue, however, i did read someones suggestion about a small piece of metal gasket sticking into a cylinder touching off when it gets red hot. wouldn't that eventually burn off if in fact that remote possibility existed? i want to either confirm or eliminate the shop having given me the wrong block or screwed something up like heads to the block. which reminds me, where are casting numbers found?


lean fuel. well, putting a FP gauge reveals nothing as i have good pressure when the books tell you to check. if i had a failing pump i assume id have other symptoms. so, something could be telling the engine to lean out- what does that? and are we talking about pressure or flow in a lean fuel situation?

engine timing could be a lot of things. what are the usual suspects? i have no CEL's so nothing to go by there. when using a timing light on the balancer pulley, timing seemed to be ok. advanced 20-30 degrees, changing when flicking the throttle and going 10 degrees out when pulling the shorting bar.

so WTF. only thing so far that i didn't get to test well was higher fuel octane that got hosed when the wife took the truck and filled it up for me on regular...

so for the redundant long post, but something has got to be telling the motor to be off in one situation or another and i cant nail this and its driving me crazy.

 

[fireguy12117]

ok, so, i'm just going to throw things out there and perhaps something will click.

the last thing i did was actually 'fix' and exhaust leak at the manifold to Y pipe by way of putting in some hedman headers. perhaps i have not helped myself with headers, but i had them, they were free, and i knew the stock exhaust had leaks.

i unplugged the battery over night. plugged it in, just took it for a drive. i could hear noise under moderate acceleration on surface streets the first few miles. that did get better, so basically no perceivable noise- not saying it went away. taking on the freeway though revealed obvious noise at acceleration.

i use the words noise because:

how do you determine if you have improper timing versus pre-ignition or dieseling? and does resetting the ECU and noticing what i just did reveal anything, a particular direction to go in?