Spark knock/rattle driving me nuts!

[Blue 04 Z71]

Here is the story, Orig engine in my 89 leaked oil like crazy so I bought a used "350 from a 88 c1500" and stuck the orig in the shed. Got the used one in the truck and it started knocking about a month later. So I then got a Brand new 350 and installed the intake off the used engine onto the new 350. The used engine ended up being a 305 from a camaro and the intake seemed different when I was installing it but I thought it was just me. Dont recall the spark knock being bad at first. Fast forward 3 years (present day) and Im getting terrible spark knock. I had an oil leak at the intake gaskets so I figured while it was off I'll just swap back to the original intake. Had the intakes side by side and they were slightly different so I figured that the spark knock would be gone. NOT!

So here are the specs of what I have done

Timing is set a 0 deg
2yr old AC delco fuel pump and sender unit as well as new lines and filter in sept of 2011'
New ac delco cap and rotor
New ac delco plugs
New autolight wires
Seafoamed the engine.
New correct AC Delco EGR
Cleaned the egr ports in the intake while it was off. Had to chisel the carbon out of the runners so I know they are clean.
Put in a new knock sensor 3yrs ago (autozone)
Cleaned the TBI when I had it off while doing intake gaskets
New bosch O2 sensor 2 weeks ago.

And Im getting a slight miss at idle (truck shakes when it misses) In gear and while in park. Does it warming up and when its up to operating temp.

The new engine has under 15000 mi on it.

Any ideas????

 

[Blue 04 Z71]

Tested egr solenoid, tps, and cts and all are within spec. I checked the plugs and the gapper I had must of been off because they were all gapped at .30 and not .35 Re gapped at factory specs. Still pings but I just remembered that I am using the dizzy from the pos 305 motor I bought used. So if this snow holds off tomorrow I am swapping in the orig dizzy from my original 350 engine. Im also starting to lean towards the KS because I can have the truck warmed up and have my foot on the brake and give it gas and I can make it ping/rattle. Somethings not working. I will get this fixed!

 

[woody80z28]

Can you hook it up to a laptop and see if you're getting knock counts? If your knock sensor is working it should give you ~100 knock counts on startup and then report any knocks you get as you drive the truck.

 

[Blue 04 Z71]

I'll have to get a aldl cable and whatever software I need for for my laptop.

 

[fun4me]

I have heard cats rattling that people have described as valve rattle.

 

[Blue 04 Z71]

Ok i put in a new ac delco KS and did help a little but I can still hear it rattle/ping. I got my fuel pressure gauge and adapter today in the mail and hooked everything up. Turns out I have 12.5 psi at the back of the TBI.But I figured the FPR is orig so I might as well change it. Did that with the quarter trick and it bumped it to 13.5 psi. Took it for a test drive and it was doggy and felt sluggish. I pulled the quarter out and it got its pep back. I still get the knock/ping when I have it in drive and have my 1 foot on the brake and the other one blipping the gas. Its just a rattle. I might retard the timing 1 or 2 deg and see where that gets me. Im running out of options now. And just for ***** and giggles this is a total newb question but is the lower rad hose supposed to be alot cooler to the touch than the upper?? I was reading that if the engine is overheating it will cause spark knock.Truck runs at the middle mark or below it on the dash gauge all the time. I was thinking of getting a new T stat to put in to see if that helps at all. This is driving me nuts!!!!!!!

 

[Blue 04 Z71]

I got it fixed!!! I started by checking the pick up coil in the dist and it was good. So I figured lets see what my timing is (set it a 0 before) and it was a little above the mark. Granted my mark is a silver sharpie line at the 0deg notch b/c I have an older balancer with the TDC groove is at 12 o'clock. Soo I figured that my sharpie line could be off or the balancer has shifted some. I put the mark at 1 deg lower than the 0 and who what of thought No spark knock!. I took it out beating on it a bit trying to make it rattle but it won't. I can't believe it was that easy. My balancer must of shifted at some point is my guess. Either way I am sooo happy its gone! A big thanks to everyone that helped me!!