scoutcamper

Hey Everyone,

Got a knock sensor question that I haven't seen posted anywhere else, so thought I would ask the question.

I have a 87 350 TPI that I moved the top end of a 91 305 TPI over to in order to use the SD setup and delete the 9th injector etc. I did put the correct 350 injectors in.

I am up against a budget wall here, I should be able to get the motor started in about 5 days but I only have the knock sensor from the 305 that matches the 7730 ECM, or the knock sensor from the 350 that matches the 87 with ESC.

My thought is, keeping in mind I will not be driving the vehicle at all until I get my next cash infusion at the end of the month, if I use the 87 350 ESC sensor wired directly to the 7730 ECM will that simply emulate having no knock at all? Or will that simulate maximum possible knock and thus make the ECM retard my timing to the maximum value?

Again, not actually driving this, but for the benefit of starting the truck without my timing being retarded and the engine running good I am looking for best option here. I also could simply unplug the sensor but my understanding is that would cause the ECM to think there is massive knock, which is not my goal....

Thanks!
Scoutcamper

scoutcamper

Also note that I am burning my own chip based of of S_AUJP_v4(only changes made from the standard bin are setting VSS to 8K ppm and VATS disabled), so if that tune has knock sensor disabled(i see conflicting reports on that) then this discussion is a moot point!

Thanks!

Vanilla Ice

If you aren't driving, use the 305 KS. It has been done many times, and driven as is, but safety will benefit from a correct knock sensor.

Many people upgrading their 305 to 350s would to the swap and not look twice at the sensor. My brother did it 15 years ago and it caused no issues in his car. Not to say it's actually safe, just doable.

scoutcamper

Awesome. I will have the correct sensor before I actually take it for a drive, but I have been working on taking the hot rod from an old 305 carb to the fire breathing 350 tpi for a few months now , its definitely time to hear the motor sing! I just dont want it to run bad due to the knock sensor...

mrestrictrplate

iTrader: (2)

I have one car that was 305 and now has a 350 tpi in it. From my searches on here I found out the speed density cars have a different ohn knock sensor than mass air cars. Mine is mass air and the sensors are different on 305 and 350's. It has to do with the bore. I bought the right sensor for the 350 and plan to turn down the knock(or off possibly) when I get my chip burned.