P0300, Low Power

2012 Chrylser Town & Country 3.6L





Waveform file:
drive.google.com/file/d/12Y7VYvpTr_QGi55...Gl_/view?usp=sharing


eScope software:
drive.google.com/file/d/1DPm_OMXMyU0jKtd...YEV/view?usp=sharing

Wow, no preamble or anything! :silly: So I have to make a call based on this waveform alone?

I guess the decompression pocket is a little deeper than the intake... IVO seems a little late... Jumped timing chain?

Tyler wrote: Jumped timing chain?

That's a good guess. How do we prove it? What would you like to see, next?

Tyler wrote: Wow, no preamble or anything! :silly: So I have to make a call based on this waveform alone?

I gave you the cam position markers....geez. :dry:

:lol:

Chad wrote: That's a good guess. How do we prove it? What would you like to see, next?

This is brutal. But hey, at least you gave us the Y/M/M/E! :silly:

VVT PIDs might be fun? But probably not necessary. If the intake were truly that late, there'd be more than just a P0300. Plus I rarely see this engine jump time.

Late IVO can also be caused by a wiped cam lobe or smoked cam follower. I see that a lot more often. :lol: Intake pulse waveform, please.

Chad wrote: What would you like to see, next?

Pics with the timing cover removed :lol:

Or 'scoping CKP and CMPs would be a less invasive option if you can find a known good.

Tyler wrote: Late IVO can also be caused by a wiped cam lobe or smoked cam follower.

Would that cause the deeper decompression pocket? I'm thinking that'd be caused by late IVC??

Matt T wrote: Would that cause the deeper decompression pocket? I'm thinking that'd be caused by late IVC??

Ummmmmm, sure? :silly: I honestly have no idea. I'm terrible about using my in-cylinder transducer. Few times a year, maybe.

Matt T wrote:

Chad wrote: What would you like to see, next?

Pics with the timing cover removed :lol:

Lol. We'll save that one for later.

Or 'scoping CKP and CMPs would be a less invasive option if you can find a known good.

Here you go:

Unknown/Suspect Cams and Crank



eScope File
drive.google.com/open?id=1gFusaVM-E0h1E1mv5iYfXIY4w00puCmO

Known Good (Downloaded from FB courtesy of Justin Miller)



PicoScope 6 Software
www.picoauto.com/download/software/sr/Pi...tomotive_6.14.25.exe

Tyler wrote: VVT PIDs might be fun? But probably not necessary. If the intake were truly that late, there'd be more than just a P0300.

We'll get to those later, too.

Intake pulse waveform, please.

RC - Voltage Inverted
NPS in Intake Manifold
NPS in Exhaust Tailpipe

Annnnnnnd there goes my cam lobe/follower idea. :lol:

Intake on B1 is definitely late compared to B2. Exhaust cams seem to be in time. Why is this not setting timing codes? :huh:

Tyler wrote: Annnnnnnd there goes my cam lobe/follower idea. :lol:

Intake on B1 is definitely late compared to B2. Exhaust cams seem to be in time. Why is this not setting timing codes? :huh:

It definitely looks a bit late but only looks to be a few degrees. I was expecting 30*ish......

Tyler wrote: VVT PIDs might be fun?

Here you go, Tyler.

Scan Data
drive.google.com/file/d/1IGgWV7FaVtfS7B8...TOt/view?usp=sharing

That wasn't as illuminating as I was hoping it would be. :blush:

But I did notice something about the camshaft behavior. Dunno if it matters or not. :huh: Using the cam/crank PIDs, with the phasers parked, intake #2 is always a positive value, while all other cams are negative.

Plus, intake #1 is always about five to seven degrees retarded of #2. Even when the intake cams are being advanced, intake #1 is always behind #2 by about the same amount. Maybe just a little bit of stretch in the chain?

Can't say that'd cause a P0300, though.

Crank "Out of Sync" :huh: I downloaded that escope software. CKP trace looks kinda rough.....

Matt T wrote: Crank "Out of Sync" :huh: I downloaded that escope software. CKP trace looks kinda rough.....

I couldn't figure out how to open Chad's capture with it. It'd only let me poke around in Demo mode.

Tyler wrote:

Matt T wrote: Crank "Out of Sync" :huh: I downloaded that escope software. CKP trace looks kinda rough.....

I couldn't figure out how to open Chad's capture with it. It'd only let me poke around in Demo mode.

Tyler wrote: I couldn't figure out how to open Chad's capture with it. It'd only let me poke around in Demo mode.

As well as the way Matt T showed, you can also load files from the Measure and Deep Record mode. This is where any zooming and cursor work is done.

That's what I needed. Thanks guys.

Can't say I'm good at it yet, but I'm getting somewhere. The CKP/CMP would seem to agree with the scan data about their being about a five degree difference between the intake cams. Still not sure that adds up to a rando miss, though.

Okay, guys and gals. This one has taken an unexpected turn. I was wanting to call a timing kit, on this one. Scan Data showing "Crank out of Sync" lead me to go In-cylinder. I thought I was seeing late valve events in the In-cylinder waveform. However, looking at the Cams/Crank correlation, rather than seeing Bank 1 Intake as late/retarded, I was seeing Bank 2 intake as being early/advanced, about 5° - 6°. Bank 2 is buried under the plenum, so I can't go I'n-cylinder. Scan Data Showing Bank 1 cam/crank difference of -3.5°, and Bank 2 showing +2.5. Although I am seeing small Timing Issues, I just can't bring myself to pull the trigger on doing a timing kit. That is why I brought it to the forum. I was hoping to get some confidence in doing a timing kit. Or, I was looking for someone to tell me to quit going down the rabbit hole, and guide me in the right direction.

I reached out to Weycraze, as he has steered me in the right direction a couple of times before. He recommended taking a frequency of the crankshaft to see if we could see a Bank-to-Bank contribution difference. A great idea! I used the CKP/Misfire function of the eScope to plot crank frequency, with the cylinders labeled. However, the results leave me more confused about what is going on than before.(on a side note, the ATS CKP/misfire function is awesome!)



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The Crank Frequency doesn't look pretty. However, I can see no rhyme, or reason, for the frequency changes. They seem to be all over the place. I, finally, decided to perform a Cam/Crank relearn, clear codes, and go for a long test drive to get a fresh look at mode 6. The thing performed beautifully. It didn't miss a beat. Mode 6 showed no misfires over a 50 mile test drive. No loss of power. Fuel trims look great. Suddenly, the vehicle seems fine. However, scan data VVT pids look the same. :woohoo: It, still, says "Crank out of Sync". Scan Data, still, shows Bank 1 cam/crank difference of -3.5°, and Bank 2 showing +2.5. :dry:

I recaptured Cams/Crank correlation, and can still see a 5° advance on the Bank 2 intake but, haven't compared it to the first capture, yet.

Right now, it is running so good that I can't justify fixing it. :ohmy: :sick: :blink: :woohoo:

Tyler wrote: Still not sure that adds up to a rando miss, though.

Preamble:

To be clear, I never experienced a miss. I DID notice a lack of power, and could smell sulfur/rotten eggs on heavy acceleration, though. The customer complaint was CEL on, and running rough. My junior tech had the first go at it. He said that it was counting misfires on 2, 4, and 6. When I took over, it was running, kind of, okay? Just a bit of power loss, and sulfur smell on heavy acceleration.

I thought I knew where this one was going, but ended up clueless.