GM ESC modules and matched knock sensors.

[dfarr67]

I know it's up to me to see whats best for my system but I wanted to know what experience is out there with false knock or overly sensitive system. 383 TPI (EBL) in 89 K1500. Was using BLH ESC module with correct knock sensor for vehicle (mismatch), I am going to try going back to the correct ESC module and log, has the matched knock sensor for the BLH module proved to be best, just want to be sure before purchasing ACD 213325, have ACD 213324 installed with 45deg elbow. Robert R says they will work together, my reading suggests match components.

[NomakeWan]

The unfortunate truth is that once you start changing components around, you lose the "precision" of the knock module intended for the original application. The module is a filter that rejects certain frequencies and allows others, converting this into a simple on/off for the ECM/PCM to read as knock. The only "right" way to get a knock module to work with a particular custom setup is to use a scope on the knock sensors to monitor knock and then induce some on purpose on a dyno, note the frequency range, and then create your own knock module accordingly. Which...yanno, kind of out of reach of just about everyone since at the moment, the knock modules are something of a black box, not to mention the skill required.

I do wish you the best of luck though. Maybe you'll get lucky and there'll just happen to be an existing module that works decently for you.

[dfarr67]

I have 3 or 4 EC modules I can try and log, easy swap.

http://www.gearhead-efi.com/Fuel-Inj...ESC-and-swaps!
http://www.gearhead-efi.com/Fuel-Inj...-(My-91-C1500)

[1project2many]

Which...yanno, kind of out of reach of just about everyone since at the moment, the knock modules are something of a black box, not to mention the skill required.

There are interesting discussions about how to do this reasonably well with budget tools. I believe there was a great thread on thirdgen.org. When you consider the aftermarket uses the same sensor for several different engines it seems like it would be easy to make an improvement.

Technology has changed so much over the years. Are there any aftermarket systems that monitor spark energy and pattern to determine knock? I could often see it on an analog oscilloscope.

[dfarr67]

I bought a stand alone system out of Iceland for the Toyota- which at the time didn't offer knock, for an extra $200 now you purchase an option which includes WB and knock- have to force knock on a dyno to tune. This is off my topic tho, I tested the oem ESC module on the Chev and it was the same if not a little more sensitive, not sure I want to purchase the matching knock sensor- both applications are 350cid one is a 85 Corvette TPI (BLH) and one is 89 K1500 TBI.

[NomakeWan]

Just remember that the sensor and the module are two totally different things. I'm not suggesting you need to do anything with the sensor. But if you want the existing EFI to do knock retard like factory, then the knock module is what you have to adjust, and all it does is pull a line low to tell the ECM/PCM when it thinks knock is occurring. Sounds simple in theory, but when we don't know the pinouts for the module and have to account for how much knock to report and when, things get tricky.

There are absolutely other ways of doing it. It's ultimately only if you want to use factory hardware that you end up in the situation where you would need to create your own custom knock module.