Overboosting, wastegate failure?

[Ross]

Your MAP reads 255 kpa, which is 37.5 psi.
Your boost reads 30.1 psi
Your desired boost reads 36.8 psi.
Looks like the desired is close to the MAP.

You don't need to graph the STFT B2 and LTFT B2 as our engine only has a bank 1.
Also IAT's (102F) are bouncing off the top of the chart (100F), could give them more range.

 

[Zklonne]

Trying to adjust a bit and got the wideband hooked in - now I have to try to understand whats happening. I’ve compared these logs for hours trying to see if I can tell what’s notable but nothing seems definitive.
Since I’m still a rook The logs are below. First is a full 3rd gear wot with the sputtering (painful to listen to). Second and third are feathering trying to stay at 10-12psi boost (One is during the “good” part of the pull and one as soon as it spiutters and I let off the throttle a bit) where it seems to pull without sputtering. I’ve now adjusted the plugs to .032” to ensure we’re not blowing out and retested boost leaks to 30psi for a full minute so I think those are checked off. I’m starting to get to the point of “stuck” where I don’t know what to try anymore.

 

[Ross]

That first pull looks a little rich. Under power enrichment I like around 12.5:1 fuel ratio (.85 lambda), looks like you got below 10:1 at times.
Your full throttle only reads 83% ?

 

[Zklonne]

I thought it seemed a little rich for the wot pull on the first - lowest I saw was 11.1 :1 on the log which is low but not terribly lower than the recommended enrichment. Seems right on the edge of “ok” and “there’s a problem”. And I’m definitely a rookie on timing and spark advance but im hoping someone might be able to tell me if 5-9* at wot is normal, I believe it just highly dependent on the tuner (ZZP in this case). My biggest issue is since we ran fine With zero issues for 30-45 min last week so what could have changed so drastically to go from not working - To working fine - then to not working again. It seems like it has to be something minuscule, but at the same time it just doesn’t want to play nice!

 

[Zklonne]

As for throttle position I think I’m logging actual throttle plate position which goes from 20-80% - I have a relative throttle position pid which’s reads 0-100%

 

[Ross]

Spark tuning is basically: slowly advance it until you get knock, then retard it.
I didn't see any KR in your logs.
Is there something in the logs at the point it starts sputtering? I see where you get out of the throttle, but don't see any logged issue before that.
PS, you can post the whole log file on the forum.

 

[Zklonne]

I wasn’t getting any readings for KR or knock detection - Do you know where this comes from? I have the afr gauge connected in place of the O2 sensor at the moment but I doubt it would be reading from there? I think the worst part of going the buy vs build route Is I have no idea if a disconnected connector is supposed to be plugged in or not. I’ll post a few log files , thank you for the pointer!

I’m trying to watch for anything in the logs that bounces around during the sputtering but don’t notice anything jumping out. It does seem to follow right when boost levels are around 10psi - which doesn’t Necessarily mean its boost related, but my goal with trying to hold just below the sputtering point Is to potentially see a little flutter or something when it did hit that point. But I’m just not seeing anything yet.

 

[Ross]

Under the oil filter (on my LSJ) is a knock sensor.
The Cobalt has an O2 sensor bung in the exhaust manifold (which is where the stock pre-catalytic converter O2 sensor goes)
and the Goblin has an O2 sensor bung in the muffler (which is were I put my wideband O2 sensor.) I removed my post-catalytic converter O2 sensor from my Goblin.

Maybe record a video of the sputtering, to help us understand the issue.

 

[Zklonne]

So I found both knock sensors which are both connected to a harness then run into a huge loom that I think goes to the ECM. Verified again that I have no channels that get readings for any kind of knock detection or knock retard - so I'm not sure what this means. I'll have to do a little homework and see why they wont show data.

I uploaded another video here of a wot pull through 2nd and 3rd gear - hopefully with better audio to hear. Also have the log files from the other day - "Pull" is wot held and letting it sputter throughout, and "feather" was where I tried to keep it just under the point where sputtering occurs.

 

[Ross]

When the knock sensor detects engine knock, it retards the spark timing. So it is often referred to as "knock retard"

 

[Motoracer110]

I had the same thing happen to me and I found out one of my plugs came unplugged. I plugged back in and still the same issue. I pulled the positive off my battery for a day then hooked it back up and the car drove good again. I feel like it reset any error fault I was getting. Might be worth a try with the battery

 

[Brian74]

What are you data streaming with? I rode in that car with Rich with my scanner hooked up, and was able to get kr values. Have you tried calling ZZP? I think he bought his (canned) tune from them, which was later on. I would consider finding a good tuner and paying for an hour of dyno time.

The low compression in the one cylinder is a concern.

I don’t know what the mileage was on his donor, but these cars are often owned previously by ignorant Vin Diesel fanboy kids. May be worth biting the bullet and transplanting a crate engine.

 

[Zklonne]

Im using HP Tuners to log - i repolled parameters and got KR* to show up now. Ran a few more pulls tonight and not showing any KR which should mean either things are safe n sound or the sensors are garbage - uploaded the log file in case any of our local experts care to peak. I definitely dont like holding it pinned through the sputtering but im hoping something pops out. All I really notice here is in 4th gear "feathering" at medium boost/throttle/load levels (this is where it pulls smoothly, just below sputtering) I have a ton of negative short term fuel trim -30%, which goes right back to 0% - ish after mashing the throttle. Confirmed the same thing in another log while feathering the throttle. This was my first drive having the stock O2 sensor reconnected since I just found the 2nd bung for my wideband sensor, which may be adding to the big short term trims?

I am at a point now where it might make sense for me to call ZZP and see if they can offer anything to help out. I'm also not opposed to going the new crate engine route or doing some major upgrades (pistons, rods, ZZP stage 2 head/cam/valve kit, etc) but I'm trying to hold off until after August when we are suppose to try to run this thing from MSP to Chicago and back. What still confuses me here is one day 2 weeks ago when it "magically" worked great for a half hour and then went back to the sputter. Makes me feel like it is something similar to what Motoracer said above (which I will try by the way - Thank you!)

I've kind of ignored these DTC's thinking they are from things that were disconnected during the build, can anyone confirm?
0x7E8: P0030 - HO2S Heater Control Circuit (Bank 1, Sensor 1) (Current, Old, History)
0x7E8: P0481 - Fan 2 Control Circuit (SES, Pending, Current)
0x7E8: U0121 - Lost Communication With Anti-Lock Brake System (ABS) Control Module (Old)

 

[Brian74]

The fan 2 code should be there as the parallel & #2 fan relays are no longer used. ABS code normal as the EBCM is removed.

Not sure about the HO2S heater control.

 

[Ross]

The only thing I noticed in the log files was the STFT trims seemed off.
When it is "sputtering", I wonder if it is running on 3 cylinders. If you have a point-and-shoot temp gauge, I think you could test this theory. Kill the engine after a few seconds of sputtering, and coast to the side of the road, take the temp of each exhaust port, and see if only 1 is colder.
Might be that one with low compression... or a bad spark plug/coil.

 

[Zklonne]

I wanted to wait to make sure the problem didn't wiggle its' way back before posting here, but one message from Lonny helped find and then fix the issue..... Ross' last message also would've led me there, but my temp gauge hadn't arrived yet. I was pretty dumbfounded to find out the original issue was a bad ignition coil which we then replaced with ANOTHER bad ignition coil under heavy load (last time I buy those from Amazon...). Anyway, a full new set of coils has us back running strong.

In the meantime, we got the livery kit for Crown Rally installed a few weeks ago - 2 weeks now until launch. I'll make a new post for some of our prep work we've done to the car to prepare for the 3 day, 2000 mile trip.

 

[Desert Sasqwatch]

Niiccceee! That is going to be a blast! Hope the weather cooperates for the trip. There are some fantastic roads in SW Wisconsin, all over SW Wisconsin! Have fun and be safe. I am sooo jealous!

 

[DCMoney]

I wanted to wait to make sure the problem didn't wiggle its' way back before posting here, but one message from Lonny helped find and then fix the issue..... Ross' last message also would've led me there, but my temp gauge hadn't arrived yet. I was pretty dumbfounded to find out the original issue was a bad ignition coil which we then replaced with ANOTHER bad ignition coil under heavy load (last time I buy those from Amazon...). Anyway, a full new set of coils has us back running strong.

In the meantime, we got the livery kit for Crown Rally installed a few weeks ago - 2 weeks now until launch. I'll make a new post for some of our prep work we've done to the car to prepare for the 3 day, 2000 mile trip.

Is your coolant hose leaking near where it comes out of the frame?

 

[Zklonne]

Is your coolant hose leaking near where it comes out of the frame?

Good question - I just saw the drip mark in the driveway. I wouldn’t be surprised.. I had a slow drip from that fitting on the drivers side when I first got the car. Just had to tighten the clamp. Thank you for calling that out!

 

[OptimizePrime]

@Zklonne Is it possible to share your tune?

Take a look at this link and see how far off your tune is from this post: https://forum.hptuners.com/showthread.php?26232-The-LNF-Tuning-Guide

Also watch these vids and see if your tables are significantly different: https://forum.hptuners.com/showthread.php?38868-LNF-Guide-Videos