ive got a 1985 iroc-z that came with a 305 tpi. i swapped a 350 in with the tpi setup. it ran great for about a year as a daily driver, and when i got a car that was better ong as for my daily i parked it for about a month. once i started driving it again it developed a terrible spark knock. first thing i thought was gas, so i ran some fuel uinjector cleaner thru and its been about 8 tanks of gas since then, so i scratched that off the list. next i thought timing, so i set it 3 times, and on the last it was ALL the way back to 6 degrees, so i scratched that off the list. the last thing i oculd think of was egr, and it had a brand new egr vavle on it, so i replaced the egr temp sensor, the only hookup to the egr. it is still spark knocking, but not throwing any codes other than the esc failure code from knocking. i talked to one mechanic who said since i have 8.5mm wires i might be trying to suck too much spark through the wires and the stock ignition cant keep up. is this reasonable and/or does anyone else have any suggestions of what i should do, thanks guys, irocnz

 

O.K. There's a new one on me. "Suck too much spark through the wire"? I'd be hunting for a mechanic with a slightly better grasp of basic electrical theories and concepts.

Consider the possibility of a detonation sensor that has gone deaf, or has poor connections.

 

A new knock sensor is ~$40 -- just be sure to drain the coolant before beginning and grab 2-3 gallons for refill (for a V8). I don't think the sensor went dead just sitting there, but it's not a bad idea to replace anyway if it's stock. Could be getting old. Aside from that it's either wiring, spark module or the ECM. My bet's on a corroded connection.

 

Have you tried a simple tune-up to fix this issue? The car might need new plugs/cap and rotor (you said the wires were newish, right?). It's very possible for the terminals on the cap to get corroded with no use for a month.

Have you tried putting octane booster in the car?

Any vacuum lines rotted through or cut or anything that might make the car run lean?

 

time to laugh at me guys haha, i have a set of shorty headers on the acr, and let them go too long without tightening them once, and couldnt get to the back bolt to tighten it back down when i was done so i had to send it to a dealership right before i parked it to get them to do it for me. while there the mechanic had to put the car on the lift, drop the strater and remove 3 plugs to do it, but he did it. all of yall taht know about these things know the knock sensor is right about the starter basically, well is his work he unpluged the damn thing and let it unplugged when i got it back. it only took me about 4 weeks and countless hours cause thats the last thing i thought to check. sorry for wasting yalls time, but thanks guy.

 

Glad you got it fixed Thanks for responding with the solution to your problem as well