hey guys,
in march i will be converting my 305tbi to tpi and i bought a full set up off of a guy from my local fbody club and he said i have everything but a knock sensor. now my question is, what is a knock sensor? and what does it do? and what kinda price do they usually go for?


thanks!

 

Knock sensor senses spark knock/detonation and help computer control timing. Its located on the passenger side of the block, below 4&6 spark plugs. Its round and has a single wire connector. Yes, you need to change it when swapping TBI to TPI. I think they're about $35.

Dave

 

any thing else i should change/replace when i do the swap? im planning on slapping a LT1 cam in at the same time, and aluminum L98 heads too if i can find them.

 

I don't know why that would be the case. It's still a 305, TBI and TPI use the same sensor.

 

you dont have to change it. your just putting a different injection system on it. knock occurs within the block which youre leaving the same.

 

When I did my swap, I came up with two different part numbers for the knock sensors, so I changed mine.

Dave

 

Far as I know, there are two knock sensors for the V8 3rdgens - one for the 305, one for the 350. TPI/TBI/CC Carb doesnt make any difference. Your TBI setup should already have a knock sensor - its right in the bottom of the right side of the block, just in front/above the starter. You'll know it when you see it. Just use yours if you are staying with the same engine and just changing the EFI system.

FWIW I used an L98 knock sensor with my CC Qjet on top of a 350 and it worked just fine.

 

I just did this same swap on my 91, went from tbi to the tpi from a 91 z. I ended up having to change the knock sensor because it thru a code. Changed it to a knock sensor from a tpi, haven't had a issue since. Good luck with the swap