New tool - A pulse sensor

Bear with me here as I'm completely new to this tool. A friend I met on a facebook auto tech group has a side gig where he creates these pulse sensors and mails them out to you. So I ordered one and here is my first capture.

It doesn't give actual pressure or vacuum numbers, it simply shows pulses of either. Above 0 is pressure, below is vacuum. I hooked this sensor up to my car (2003 Accord 2.4L) on the brake booster vacuum hose, just as a testing scenario and to see how it works.

This is my K24A motor running at 2,000 RPM. Red trace is the pulse sensor, green trace is cyl #4 ignition command squarewave from PCM, to act as a sync. Firing order is 1-3-4-2. Sorry about the noise on that channel(but it sorta helps identify other cyl TDC)

I have added pointers to the thing I want to discuss. I believe I may have found an issue with my car, I'm just not 100% sure on how to read this sensors output.

If you follow the math, the problem area is occurring at the cyl #3 firing event. Being that it's an intake vacuum capture at that moment, it must be 180 degrees from #3(the next cylinder to fire), meaning the cylinder/valves producing that jagged vacuum pulse must be #4 , right?

Also, I'd love to hear any general input on the pattern as this is brand new to me, first use ever.

With a Honda especially if it has a 60,000+ miles under its belt I would suggest adjusting the valve clearances

Inlet Valves : 0.21-0.25mm (0.008-0.010in)
Exhaust Valves: 0.28-0.32mm (0.011-0.013in)

Deltron,

Can you please perform this test over, except, do an engine cranking analysis, not engine running.

Use your exact same scope set-up, disable the fuel pump and crank away!

Please post the pic.

Thanks

Congrats on the new tool! Who did you purchase from? I just recently got one from Cody's.

I agree with Weycraze, redo the capture cranking and fuel disabled. Since it's a K24, disconnecting the injectors might be the easiest method. Running intake waveforms can be tough to decypher, due to events happening so quickly.

I threw an overlay up on your capture for clarity:



Sure looks like it's the #4 intake pull that's weaker than the others. Again, I wouldn't get too excited until you do a cranking capture.

That overlay has had my mind churning for a good 10 minutes. Good stuff. Whered you get that?

Overlay can be obtained here:

driveabilityguys.com/software-and-tools .

I agree with Tyler, it does look like a weak pull on Cyl#4 Intake.

However, that can also be caused by a weak power stroke from companion #1 Cyl. ie, crank slowed down hence the weak pull.

Tyler wrote: Congrats on the new tool! Who did you purchase from? I just recently got one from Cody's.

Cody does a great job. Nice guy. I recently saw that Michael Nicholson is making pulse sensors again. And not only with BNC but in combination with banana jacks. Think I might get one.

Glad to hear he's making them again! I don't regret buying from Cody at all, but I initially went looking for Nicholson and found he'd stopped.

Thank you Deltron.

Dylan, I'm glad you got geared up. Cody is a friend of mine and we first met because of these sensors. I'm surprised to hear that I stopped making them though. I never stopped just had complications with the website. That was only up for 3 days.
I'm still pushing forward on building these. The gen3 is a more universal application for a verity of scopes.

So I've taken a cranking capture.

Take note that the "weaker" intake pull is now cyl #1 (sync is #4 again, 1-3-4-2)

You can see that on my original capture at 2k RPM, and the sawtooth pattern that I was concerned with seems to be an anomaly all it's own, and I'm wondering if it's actually a cylinder specific vtec problem.

Did I overlay this incorrectly? :huh: Or does it look like the #3 pull was weak(er)?

I JUST got my overlay software and did that as you posted it, and you're right. It's 3 that's weak.

Deltron wrote: I JUST got my overlay software and did that as you posted it, and you're right. It's 3 that's weak.

Sorry about that. :blush: I don't get to pull out my overlay as often as I'd like, so I get excited when I have an excuse!

I must say, that is a good looking wave form. :silly: But I do agree that Michael and Cody make excellent sensors as well. I haven't been on this forum is sometime, but I'm glad I logged in. Hopefully we can get a surge of more posts like this. But as far as your wave form, like others stated I would start with valve adjustment.