I have just recently finished my 350 tbi swap but not sure about a few things. I bought the car with a 350 in it. I assumed the car was given a new esc module and new knock sensor becasue it won't run without those. For some reason, after i got the chip tuned by Kevin91z, it still knocks like hell. what could be the problem? knock gone bad, just an overall problem with the engine? any help would be appreciated

thanks
brandon

 

also... i have a bad exhaust leak (stock manifolds), could this be causing a knock?

 

The exhaust leak could definitely be causing it, if its loud enough. I would never assume that the knock sensor/ESC were replaced with 350 ones, the car would run with that, it would just detect false knock more often I think, and maybe not detect actual knock some of the time, due to different frequencies.

If this guy tuned your PROM and now it's knocking, make it his problem.

 

no it knocked before and i had hoped the tune would take it out. He is the one to tune every third gen in so cal so i doubt it was him. i am going to take out the exhaust manifolds and tighten up the air tubes and hope that will cure it. I know the engine shop that put the engine in put gaskets on the manifolds and from what i've heard that's not right. There supposed to match right to the heads right?

 

When does teh knock happen? Is it a metallic 'ping' under load, a metallic hammering sound at all loads at certain RPMs, or just all the time?

 

It sounds more like a rattle after putting some gas into at any rpm, cruising there is no knock. When i get into it it sounds horrible. It's gets worse as i shift into a higher gear

 

What is your base timing set at? How many chips did he burn for you and did he have access to your car when doing so? I would check to see that you have the 350 KS and ESC module.

 

Yeah he drove it, took numbers, and again and again until we got the least amount of knock, best air fuel ratio and so on. I talked to him and said it could be something in my valvetrain causing false knock. I was also told that the 350 and 305 knock sensor are the same part. I am not sure about the esc though. How can I check?

thanks

 

nope... different sensors you need a 350 k.s.

 

305 use a different ks, 350 and 400's use the same.

 

i think the esc for the 350 and the 305 is different too, i'm not sure though but you definately need a new knock sensor

 

u know my car has a knock \ tap from the bottom of the engine and i dont even think i have a knock sensor i have a 88 t\a and swapped in a 350 tbi. Do i have a knock sensor and if i do where is it?

 

u should, passenger side near oil pan

 

what does it look like what color is it like a little round thing with like a dawn liquid soap squirer for the conector.

 

sounds right, maybe 1.5" diameter, single wire plugged into it, its in the center of the side of the block near the oil pan.

 

i fixed the passenger side exhaust leak so today i will do the other side. hopefully my knock will go away then. if not i will change out the knock

 

sounds good

 

The passenger side was real loose, i really used just a socket to remove them, the socket driver wouldn't ratchet back they were so loose. Hopefully this will cure it.

 

any news on if it fixed it?

 

I had the same problem on my stock LO3... now I run 93 octane and it's gone... I guess I was pinging from massive amounts of carbon built up...

 

i didn't get to the driver side yet. I had the engine rebuilt two years ago. I have only run 91 since i bought it. I know that's not the problem. Hopefully tonight will tell.