Car sputtering and cutting power at WOT
 

As I approach 150k miles and 130k boosted miles on my car, I'm starting to see issues. I'm not sure if I have a vac leak but when I WOT my car, power is cut and the engine doesn't want to climb in rpms at random times. It just hangs at say, 4k or 5k rpm under WOT. It happens quite a bit. It's more pronounced on pump gas than e85. I'm thinking this could be the effect of a vacuum leak somewhere. I'm not sure what else can cause this.
Any one else experience such issues?

Vacuum leaks usually happen at low RPM, not high RPM. That is not a typical vacuum leak symptom

Failing fuel pump? Coil pack? Spark plug? Clogged injectors?

Perhaps failing MAP sensor? A lot of these OMNIs are shitting out on people lately.

What does your AFR look like when it happens, have you taken a log to see timing, engine load, boost when the issue happens? Is it particular to a single gear? etc..

+1 on the MAP sensor as my first thought.

+1 for the MAP sensor as well. There have been several reports of Omni MAP sensors failing, and the symptoms fit.

Let's see LTFT and STFT at idle, 2500 RPM and WOT

Thanks! I'll try to gather this info this weekend.

Clogged fuel filter?

I've attached some data logs. I don't know if they indicate anything. Basically I give the car some throttle and right before i let off the throttle is when the engine dragging starts happening. Basically the engine sounds like it's struggling and doesn't rev higher even with throttle. Not sure if it's a misfire or what. What's interesting, it's worse the lower the ethanol level. Basically the car performs better with higher E content and performs like crap on pump gas. This issue just started happening.
If anyone sees anything wrong,
Thanks

Your AFR and MAP is pretty wild, along with some fuel trims.

Replace your MAP, or test with a known MAP.

Interesting I'm experiencing the problem once and awhile these past about 3 months now. I have about 35k miles with less than 10k on boost (JRSC C38) on stock MAP. It's happened on 91 and e85. I can't figure it out.
This is a data log using Torque App over a month ago.
https://datazap.me/u/dru670/engine-s...17-18-19-20-21
Been meaning to do a data log with ecutek to have my tuner take a look at it.

Perhaps I'm misreading your post...but you are supercharged on the stock map sensor? The standard JRSC pulley makes more boost than the OEM sensor's range.

I'm having similar issues, but its moreso when I'm on higher ethanol content, cruising on low rpms. Weird part is that the issue comes and goes but doesn't happen on 91.. its got a mind of its own :iono:

That's not an issue. You don't need a larger range sensor than OEM, it just caps the pressure reading.
Can you log the car? Where is the FF connected to (Rear O2 or CPC)? If the O2 sensor port I'd check the AF#3 correction values in the log.

Huh? How would the ECU not being able to determine the correct manifold pressure not be an issue?

I suppose on a supercharged car where boost should always (assuming everything is working fine from a mechanical perspective) be the same amount it would be less of an issue...but I would still be weary.

I have the PTuning FF kit.

Every single Sprintex SC car runs the OEM sensor as having a correctly reading MAP sensor causes fueling issues, I have one which I tune. All it means is that I don't get over 1.36 Bar on the OBD reading, as the fueling is done primarily via MAF then it runs consistently and I don't really need to know the manifold pressure. I expect it's the same pressure as when I had it dyno'd years ago ;) Unless you max out the MAF and need to run SD then it's a complete non-issue. I also suspect that running a lower range MAP sensor would cure the odd fueling that affects the Cosworth SC kits too when in boost.

That makes sense. I'm from the turbo world, I've maxed out every MAF I've ever had and had to run hybrid MAF/MAP setups.

Update:
Changing the spark plugs alleviated some of the issue. The plug gap was worn out. It would hesitate at anything above 50% throttle. Now I'm having the issue at the higher RPM range, always at 6.5k rpm, the car hesitates and wont go. I've cleaned the MAF sensor which I haven't cleaned ever (lol) and got the same results. I have a vid below.

[ame="https://www.youtube.com/watch?v=482kHy7oUJo"]Boost issue 1 - YouTube[/ame]

[ame="https://www.youtube.com/watch?v=sQJkR8Cv5T0"]Boost issue 2 - YouTube[/ame]

The 2nd vid hesitates at 6k which it doesn't do often. My tuner said it wasn't the MAP sensor. I haven't swapped to test as yet though.

So the list of possible issues:
MAP sensor
O2 Sensor
Vac Leak?
Coil Packs?
What other possibility?
Other note is my engine has 150k miles on it. The issue did start until 145k miles.

Does your tune include FFS? I have an OFT (NA) but I set FFS RPM too low and I got weird high RPM shifting issues. Just a thought.

Fuel filter/pump? I mentioned this before. No one commented unless I missed it.

Edit: My dad’s GMC 2500 cut out power and went to limp mode. I sounded like the turbo was bypassed. The truck would not go faster than 45mph or rev as high. He changed a clogged filter, and it immediately fixed the issue.

I think you have to ask yourself what could have changed? Bad fuel, low fuel pressure, bad afr, bad spark or bad compression. Bad afr could be a header leak, a clogged cat, a boost leak, a bad o2 sensor or something but I can’t imagine you would see any of these problems with no CEL.

I noticed that the Atmosphere pressure is reading low which could be a contributing cause, but there is no CEL. I started another thread regarding the location of it.
I'm not sure if I have a clogged filter. The car runs a lot worse on pump gas than E85 which tells me it's probably a fuel compensation issue. :/

Update. It was just cylinder 1 coil pack that went bad. Nothing major. Car is running fine again. Thanks for all the help all.