Help with hesitation issue

[steve99]

Check for exhaist or intake leaks fuel trims high positive.check hoses under intake manifold and pcv valve


check directvinjection computer has all three mount bolts installed and tight so it has good ground\earth.

[MotoX16]

Originally Posted by steve99

Check for exhaist or intake leaks fuel trims high positive.check hoses under intake manifold and pcv valve


check directvinjection computer has all three mount bolts installed and tight so it has good ground\earth.

Checked hoses underneath the intake and pcv and all are still clamped and tight. DI computer has all it's bolts tight, I just put it back on when I did injectors.

I double triple checked all my hoses and did a boost leak test today and found a massive leak coming out of the maf sensor. Replaced the oring and got that fixed. But still having issues.

Going to try testing the O2 and I want to throw fresh plugs in it too. Need to get some more logs now that I've fixed that leak. Thank you all for the help! Not super hopeful I'll get it solved before the track day but I am enjoying working on it

[MuseChaser]

Whenever I get faced with a hesitation issue, I just put on my big boy pants, suck it up, and tell myself, "Just go ahead and DO IT!"


......

I'm sorry. I've been fighting the urge to post that wise-guy response since I first saw this thread days ago. I just lost the battle.....

[MotoX16]

Alright here's some more data logs since I fixed my maf leak.

Startup and Idle: I see and hear/feel some misfires. I think its safe to eliminate the throttle body as the issue here. Fuel trims look alright too when its missing although they are still kind of wonky other places. Going to throw some new plugs in this week and see what happens.
https://datazap.me/u/motox16/823-idle?log=0&data=30


Acceleration: Dont even know where to start, lots of things look wrong
https://datazap.me/u/motox16/823-accel?log=0&data=30

[MotoX16]

Well I got new plugs in it last night and it seems to have fixed the issue. Drove it around a bit and didnt feel any missing/hesitation like before. Now I'm leaning one of two ways.

One, the mechanical issues are fixed, and the maf had been leaking for a while. If air was leaking out from after the maf and tuned like that, then the computer would be adding more fuel (positive trims) to compensate for the extra air the engine is seeing now that the leak is fixed.

And I had one or two etune files that were pig rich, like filled up my catch can with e85 rich. Idk how that happens but before and after the etuning process my catch can collects very little. During tuning it overflowed with what seemed like much too liquidy to be oil. Causing an early demise of my plugs, although they looked alright I could notice the side tips had rounded a bit.

Also my ID1000's measured at 900cc flow, so maybe that injector data has been off in the tune file, not sure what its supposed to be but they all matched and flowed well. Conclusion, just needs to be retuned now.



Or two, the problem is intermittent and just didnt show its face last night. It rained and temps cooled down a lot. Will continue to drive and take logs as I'm not entirely convinced everything mechanically is sound.

Logs from last night:
Idle - https://datazap.me/u/motox16/826-idle?log=0&data=24-30
Cruise - https://datazap.me/u/motox16/826-cruise?log=0&data=30

[blsfrs]

I'm confused. What exactly was in your catch can? And why was it there?

[MotoX16]

Originally Posted by blsfrs

I'm confused. What exactly was in your catch can? And why was it there?

You know now that I think about it probably wasnt fuel...I just thought that since the car ran so rich for a minute but that cant be it. I was getting etuned back in winter so hard to remember, maybe it was condensation?

It was pretty liquidy, smelt like fuel/oil, and was colored like a watery brown/tan. Since we did the last tune revision in like January of 2020 I havent had really anything build up in my catch can though

[Dzmitry]

Originally Posted by MotoX16

Well I got new plugs in it last night and it seems to have fixed the issue. Drove it around a bit and didnt feel any missing/hesitation like before. Now I'm leaning one of two ways.

One, the mechanical issues are fixed, and the maf had been leaking for a while. If air was leaking out from after the maf and tuned like that, then the computer would be adding more fuel (positive trims) to compensate for the extra air the engine is seeing now that the leak is fixed.

And I had one or two etune files that were pig rich, like filled up my catch can with e85 rich. Idk how that happens but before and after the etuning process my catch can collects very little. During tuning it overflowed with what seemed like much too liquidy to be oil. Causing an early demise of my plugs, although they looked alright I could notice the side tips had rounded a bit.

Also my ID1000's measured at 900cc flow, so maybe that injector data has been off in the tune file, not sure what its supposed to be but they all matched and flowed well. Conclusion, just needs to be retuned now.



Or two, the problem is intermittent and just didnt show its face last night. It rained and temps cooled down a lot. Will continue to drive and take logs as I'm not entirely convinced everything mechanically is sound.

Logs from last night:
Idle - https://datazap.me/u/motox16/826-idle?log=0&data=24-30
Cruise - https://datazap.me/u/motox16/826-cruise?log=0&data=30

Good to hear that you're back in business. Things are looking much better. Your LTFT is still fluctuating more than it should, so a revised tune would do you good.

[blsfrs]

Originally Posted by MotoX16

You know now that I think about it probably wasnt fuel...I just thought that since the car ran so rich for a minute but that cant be it. I was getting etuned back in winter so hard to remember, maybe it was condensation?

It was pretty liquidy, smelt like fuel/oil, and was colored like a watery brown/tan. Since we did the last tune revision in like January of 2020 I havent had really anything build up in my catch can though

If you were running rich enough that your PVC was sucking up fuel, you may be in for problems down the road. That much fuel would wash the oil off of the cylinder walls. Look closely at your oil too. It is probably contaminated with fuel.

[MotoX16]

Originally Posted by blsfrs

If you were running rich enough that your PVC was sucking up fuel, you may be in for problems down the road. That much fuel would wash the oil off of the cylinder walls. Look closely at your oil too. It is probably contaminated with fuel.

The oil was contaminated with fuel too, I remember it smelling a lot like gas when I changed it after that incident. It didn't run long like that though and I've changed the oil many times since then

[MotoX16]

Ok I'm working with my tuner again trying to get my car back to where it was, things are better but definitely still having issues. I've got a new revision that helped out my fuel trims but still feeling an intermittent hesitation/miss. Not knocking his work at all, he's understandably busy so I'm just looking for a second set of eyes while I wait.

Where I feel the car having issues seems to be correlated to the map sensor bouncing around in the logs. Not sure if my sensor is going bad or if its just a symptom of some other issue. The sensor is a FBM 4 bar thats about 2 years old.


Here's a startup and idle log. There's one spot in there where the car had some issues
https://datazap.me/u/motox16/91-startup?log=0&data=30

Here's the first WOT log I took. Things look alright with a small bobble on the map sensor around 4k
https://datazap.me/u/motox16/912-wot-1?log=0&data=30

The second WOT log. Map sensor is jumping all over the place, could feel the boost changing as the car accelerated.
https://datazap.me/u/motox16/912-wot-2?log=0&data=30


Thank you all for the help!

[MotoX16]

It was the MAP sensor

[FrickingReallySlow]

Interesting did you replace with another FBM sensor or different brand

Originally Posted by MotoX16

It was the MAP sensor