FOX-GTA_89

can i bypass knock sensor+ modile plz help

camaronewbie

No. The ECM takes the info it gets from the knock sensor and uses it to advance/retard timing as needed so that you don't have knock. Knock is bad - if knock is happening then engine could be very short lived if it's not corrected. If you swap to a non-cc carb setup, you then can remove knock sensor, but otherwise you need it. The knock sensor can detect knocking that you cannot.

Damon

You can make the system "blind" if you want to do some testing. Just run the KS wire to a 3900 Ohm resistor (Radio Shack) and the other side of the resistor to a good ground. That's the same resistance as a stock knock sensor of that vintage but, obviously, it will never hear any knocking since it isn't connected to the real KS any more.

You can't just unplug it becuase the ECM/knock module tests that connection (I believe at startup, if memory serves). If it doesn't see resistance within a certain range it throws the penalty flag. That's why you simulate it's existance with an appropriate resistor.

FOX-GTA_89

im havin a 305 tpi car with a 350 can i use a 350 knock sensor on a 305 module?im using the 305 for now...

im affraid that my ecm retart timming due to wrong sensor + veryloud headers and exhaust

wyochimneysweep

iTrader: (1)

i understand the modules are the same and the knock sensor is whats diffenert.

FOX-GTA_89

305 and 350 tpi are exacty the same exept

block
heads
knock sensors
distributor module
injectors
belt routine

johnf123

so swapping to a carb, removing ECM and gutting wiring harness/swapping to painless, i can just plug knock sensor hole? im swapping a 305 TBI for a base GM crate carb'd 350 with roller cam, alum heads, headers, gear drives and blower.

sofakingdom

iTrader: (1)

Of course!!!

Those engineers back in 1955 when they invented the Small Block Chevy, they just KNEW the Frod engineers were going to be looking over their shoulder; so instead of letting on that they had a crystal ball to see the future with, they CLEVERLY DISGUISED the knock sensor port, since of course in 1955 they already knew EFI was coming SOON, as the passenger side coolant drain hole.

So you can just go back to the old-school thing and put a ¼" pipe plug in it like we all did from 1955 up until 81 or whenever it was that the computer-controlled carb appeared.

Damon

Wisenheimer, Sofa. Don't tease the young'uns. They don't know because they weren't even born before EFI engines were commonplace. Not their fault when they were born.

He's right, of course, he's just poking a little fun at you.

johnf123

yeah im 17 im learning alot from my build! most kids my age blow ther money on booze and drugs and me and my best friend blow our money on my camaro haha

eseibel67

Cars are also a waste of money, but at least your having fun and learning something. The skills you acquire in car repairs will come in handy in the future when your refrigerator craps out. Not too many kids these days are interested in cars, keep it up. Your lucky that you have these forums to help you along, when I was your age, all I had was a crappy Chilton manual.