[keanecn]

I didn't have rpm before, until I brushed the official Speeduino base .msq again, please make sure whether it was brushed Speeduino base tune

[Built2runmaybe]

I think I’m getting somewhere, but not with the grey sensor. I tried brushing the tune again to see, but nothing really changed. Thanks for the input.

I tried some bench testing with the 24x sensor. Here’s the video link to the test:

https://youtu.be/5CgT2t-3Pbc?si=EGQrvoEaUmOlA-20


There are a couple of things I observed here:

1. When facing the sensor, when a ferrous object passes from right to left there seems to be a spike from 5 V to 0 V granted it wasn’t the cleanest. This behavior seem to be consistent but when you would try and pass the object from left to right or hold it in place the sensor would get stuck in the high 5v state. As long as the object passed from right to left, it would go from 5 V to zero without an issue it would make sense for it to behave this way because I assume that’s the way the crankshaft rotates.

2. This behavior occurred with, and without the 10 K pulldown resistor. However, I included the pulldown resistor to help with signal reading, and just making sure it was as clean as it can be as well as to prevent it from getting stuck on 5 V.

I tried doing similar tests with the 58X gray crankshaft position sensor and it seems like I am getting nowhere with it. For some reason I try using a multimeter and 5v supply disconnected from the speeduino to just test what I can see with it on the multimeter and nothing changes on the meter no matter what I do. I understand there’s a potential for the sensor to be faulty, but this is actually the third sensor that I have come across of the GM 58X (I have been very very much using the warranty provided by AutoZone with this part, and exchanging them to verify the sensors themselves are not faulty). I’m gonna see if I can post a video of the 58X sensor testing and maybe it will clarify what’s going on


Thanks again for all of your help. One step closer.

[PSIG]

I didn't try to analyze the testing description, but just noting that the 5V sensors must be at 5V, and the 12V sensors at or near 12V, or they will randomly 'stick' on or off. I have not seen a directional issue at proper voltage, but these things have been made by many different factories, so ... <shrug>

[Built2runmaybe]

Hmmmm… the entire time I have been testing the 5v sensor my speeduino has been giving out a 5v ref reading of 4.7-4.8v. I thought it was just my multimeter but who knows, maybe it’s not high enough to trigger the sensor.


I’m gonna give the 12v black sensor a shot on 5v and cranking it tomorrow. It’s the closest I’ve had to an RPM reading thus far. I am aware that it could get stuck voltage wise on high but I’m willing to take my chances just to see. Seems to give me an RPM reading on a bench test using 5v, currently it’s my best shot.

Still trying to figure out the grey sensor.

[PSIG]

Voltage ±10% is fine for testing. Note GM now makes both 24x and 58x sensors in black, so verify your part. Some say you can interchange the sensors and voltages, but as CJCalhoun found, that's not always true. Verify your sensor gap and angle are reasonable to 'see' the teeth. Basics, I know, but issues with making LS sensors work are uncommon. I look forward to getting back and testing mine. Sorry I can't recall everything, as I have spec'd hundreds of sensors with all of their details. It has become a blur.

[Built2runmaybe]

No worries PSIG, the information was very helpful. I finally have an RPM signal!!!

using the black sensor on 5v, I am able to get readings on both the tooth logger and the Tunerstudio RPM gauge.

I have the trigger settings set up on basic distributor, with 24 total teeth (this is because of the generation 3 crank reluctor wheel I am using), and a trigger angle of 15 degrees.

I went to crank it and fire it off, and it pops off a little, but does not start still.

I have adjusted priming pulsewidth and cranking enrichment due to how cold the climate is where I am (20 degrees F) and i think I was injecting too much fuel, as I saw flames coming out of my headers.

when cranking, sometimes tunerstudio will register it as running when it is still cranking. so, my main new questions are:

1- ive heard that the trigger angle should be 30 degrees before TDC for this application specifically, so maybe my 15 degrees are off?

2- should I bring the cranking RPM threashhold max to 600 (i had it at 400 earlier and teh problem of registering as running still occured while cranking

probably going to make another seperate topic on this issue because I have deviated so far away from using the 58x sensor. THANK YOU TO EVERYONE THAT HELPED WITH THIS!!!

[PSIG]

Basic Distributor in not acceptable, as it has no idea where cylinder #1 is located. You must have a reference of some kind (missing tooth or cycle/cam signal, etc) for it to "find home". Do this first, as the rest can't happen right without it.

Trigger Angle must be set with a timing light. No easy way around that for accurate reference. See references for how to do that just cranking, first start techniques (e.g., wide-open to cut fuel in Flood Clear while cranking to test too much/not enough fuel), other initial settings, first adjustments once warmed, etc. A tooth log may also help, and testing Rising/Falling to best match what the decoder expects in crank/cam signal timing. Lots of little things coming together at this point, but awesome that they are.

[Built2runmaybe]

I connected up my cam sensor and set it up on dual wheel. Here is the composite reading I got on my logger:

I saw this on my composite but when I went to check my rpm I couldn’t get any reading on RPM even though I was cranking…probably because my jumper became low on power I assume. I thought my laptop would still provide the speeduino with power while cranking to read but oh well. Not sure how to read composite logger but I think this looks good? The crank trigger lines up very well with the red line (I assume is the cam sensor reading)

Thank you for all of your help.

[jonbill]

The red marks are instances of non sync. So its never achieving sync. It looks to me like its not seeing the cam signal at all.

[Built2runmaybe]

After some time I figured it out. Turns out its not just the sensor that varies by the generation of LS engine, but the 3 wire harness plug that also plugs in varies as well. Im not 100% on this theory because my harness is an aftermarket one, but when I tested the signal wire on the cam plug of my harness it had 10k ohms of resistence with nothing plugged in. I tested the generation 4 cam plug harness and it seems that it had 0 ohms resisitence. Swapped it out and FINALLY got a cam and crank signal!

it seems that not only is there variation in sensor types for the LS hall sensors, but also the harness plug that plugs into the sensors vary as well, specifically in how much resistence the signal wire has built into the plug.

The car started up for the first time a couple of days ago. Haven't started it up since then because I want to hook up my radiator to make sure i'm not at risk for overheating. I tuned it enough to get a start and an idle for like 10 seconds but Im unsure of my tune, as I have never tuned anything. Currently dont have the wideband sensor hooked up because the full exhaust system is not on the car. I heard that 22 degrees is a safe bet for ignition timing, so i used that to start the car first

Attached is my shitey tune.

Any recommendations? I currently just want to tune the car to idle (has the stepper motor IAC with accompanying chip, Alpha-N tuning as there i s no MAF sensor)

Some more details:

stock injectors and Gen 4 truck manifold and fuel rails
24x/1x Dual wheel trigger
aggressive Cam with accompanying accessories (push rods, springs, etc)
stock bottom end
0 knowlegde