I understand the protection that the knock sensor offers against detonation, however it is holding me back from a better 1/4 mile!!! I took my car to the track recently and ran an embarrassing 14.4 @ 94mph, 1.732 60'. After doing some research, i found the noise made by that quiet gear drive is detected by the knock sensor and it pulled my timing back 9deg at full throttle. I took it to a speed shop who hooked a scanner to it to come to that conclusion. My base timing is set at 10 deg advance and remains there at closed/partial throttle, until you hammer on it and then it kicks in and pulls the timing severely. Im hoping to get some huge gains after I had TPIS modify my prom and eliminating the knock sensor. Any thoughts? Thanks!!

 

You know, instead of modifying the PROM, you could have just unplugged the sensor.

 

Thats a good thought but wouldn't that throw off **** in my ECM? Check engine light turnin on and stuff? Im gettin my chip back tomorrow in the mail and plus it didn't cost me anything. I still have my stock chip I can put back in if 'being without' turns to a problem.

 

The knock sensor only sends a signal when there is "noise" in the engine. Unplugging it just keeps that "noise" from getting to the ECM.

 

Please forgive the dumb question from a TPI Newbie...where is the knock sensor located??

 

should be on the bottom/edge of the block. btw, nice vette.

 

...on the passenger side.

 

Thanks. On both accounts.

That was my next question. Thanks guys.

p.s. Not meant to be a hijack, just figured the answer was good for anyone who may not know.

 

Under certain conditions (especially high RPMs when your car is at operating temp) the ECM will _look_ for a signal from the knock sensor and when it doesn't find it (becaus eyou unplugged it) you'll get a code 43. I'm fighting with this issue right now myself. My car runs like junk with the sensor plugged in, and sets of an SES with it unplugged if I get on it when the car's warm.

 

On a 92 SD, the 43 code came on, and my car ran worse. IIRC, you can simply unplug them on a MAF car, but, not SD.

Maybe the TPIS prom is the problem. I do not know how involved you want to get in your tuning, but you can have complete control over your entire tune yourself if you want to.

If you were to get into doing your own proms, there is a table in your prom, "Max Spark Retard in PE", (power enrichment), that you can tune yourself, with your scan tool, of course.

You have a nice combination there, but it needs to properly be tuned. Your combo should be tuned from scratch, starting with the VE tables.

All I can say is a mail order tune is the worst tune you can get. If they dont tune it on the fly, (with your car), its worthless, IMO.