Breaking up at 4k rpm turbo Brz. - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Dmitri · 04-09-2014, 02:36 AM

Car developed a problem with breaking up and backfiring at 4k under boost. Ideas? 9psi, 550cc injectors, in tank 255, logs show the afr unstable and towards the lean end at about 15.1. Not going into boost until resolved. Issue started with occasional pop, now will not rev past 4k under boost. Threw a multiple cylinder random misfire code.

DBW · 04-09-2014, 07:05 AM

What are the MAF voltages doing?

Reaper · 04-09-2014, 07:10 AM

e85?

Dipstik-sportech · 04-09-2014, 07:38 AM

DI seals?

The Frozen North

Sportsguy83 · 04-09-2014, 08:44 AM

Quote:

Originally Posted by Dmitri

Car developed a problem with breaking up and backfiring at 4k under boost. Ideas? 9psi, 550cc injectors, in tank 255, logs show the afr unstable and towards the lean end at about 15.1. Not going into boost until resolved. Issue started with occasional pop, now will not rev past 4k under boost. Threw a multiple cylinder random misfire code.

I would start with verifying in tank pump install/ pump taking a shit. Second thought is destroyed DI seals.

Quick test. With car idle, if you blip the throttle, do you get firecracking pops?

If yes, hints at DI seals, if not, hints at you are going really lean because of improper pump install. I'm inclined to bad pump or wrong install letting fuel pressure leak out of O rings.

King Tut · 04-09-2014, 01:01 PM

Quote:

Originally Posted by Dmitri

Car developed a problem with breaking up and backfiring at 4k under boost. Ideas? 9psi, 550cc injectors, in tank 255, logs show the afr unstable and towards the lean end at about 15.1. Not going into boost until resolved. Issue started with occasional pop, now will not rev past 4k under boost. Threw a multiple cylinder random misfire code.

Nice second post. Can you post up said logs? Who is your tuner?

woode · 04-09-2014, 01:55 PM

Is the car only leaning out and misfire as you come into boost? Can you lightly drive up to the 4k+ rpm range without issue?

Reason I ask is because my car has similar issue when it's colder outside at around the same rpm, no matter the engine load or boost. Been chasing the issue for a while now and it's looking more and more like the MAP sensor. Changing nothing except the MAP scaling and switching back to stock MAP sensor fixed it for me but I can't actually run the stock one due to it only reading like 5psi. I know some of the innovate guys are/were also having similar issues.

No Limit Motorsport · 04-09-2014, 02:15 PM

Check your spark plugs, and also for vacuum/boost leak.

woode · 04-09-2014, 03:00 PM

Didn't somebody have an issue with the coil packs failing and causing these types of issues?

Reaper · 04-09-2014, 03:34 PM

I think that was csg? I dont remember his full name

Sent from my SAMSUNG-SGH-I747 using Tapatalk

Sportsguy83 · 04-09-2014, 04:29 PM

@CSG Mike?

nelsmar · 04-09-2014, 04:37 PM

Log with equivilance ratio requested afr. And fuel system status. Sounds like you are running in closed loop with bad injector scaling and maxing out fuel trims.

Post any logs you have for is to review and I sure we can figure it out.

No Limit Motorsport · 04-10-2014, 01:47 AM

Quote:

Originally Posted by nelsmar

Log with equivilance ratio requested afr. And fuel system status. Sounds like you are running in closed loop with bad injector scaling and maxing out fuel trims.

Post any logs you have for is to review and I sure we can figure it out.

If the car ran good for a while, than started having issues out of nowhere it probably isn't (directly) the tune.

Misfire code is telling me check the plugs/coilpack and you will probably find your issue. If that doesn't turn up anything check to make sure your wiring didn't get burned resting on something hot maybe? Or the wires accidentally ripped out of a connecter.

nelsmar · 04-10-2014, 03:49 AM

Quote:

Originally Posted by No Limit Motorsport

If the car ran good for a while, than started having issues out of nowhere it probably isn't (directly) the tune.

Misfire code is telling me check the plugs/coilpack and you will probably find your issue. If that doesn't turn up anything check to make sure your wiring didn't get burned resting on something hot maybe? Or the wires accidentally ripped out of a connecter.

I actually completely misread the OP earlier. I thought he said he was getting sputter past 4k when hitting boost. I didn't realize he meant it will no longer rev past 4k.

04-09-2014, 02:36 AM	#1
Dmitri Member Join Date: Dec 2013 Drives: Turbo BRZ, Celica Supra Location: Milwaukee Posts: 44 Thanks: 6 Thanked 14 Times in 11 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	Breaking up at 4k rpm turbo Brz. Car developed a problem with breaking up and backfiring at 4k under boost. Ideas? 9psi, 550cc injectors, in tank 255, logs show the afr unstable and towards the lean end at about 15.1. Not going into boost until resolved. Issue started with occasional pop, now will not rev past 4k under boost. Threw a multiple cylinder random misfire code.

04-09-2014, 07:05 AM	#2
DBW Motorsports Join Date: Nov 2011 Drives: 19BRZ PP, 16 M4 Location: ATLANTA, GA Posts: 67 Thanks: 36 Thanked 62 Times in 27 Posts Mentioned: 16 Post(s) Tagged: 0 Thread(s)	What are the MAF voltages doing? __________________ Douglas W.

04-09-2014, 07:38 AM	#4
Dipstik-sportech Senior Member Join Date: Oct 2012 Drives: 2013 BRZ satin white pearl sportech Location: Thunder Bay Ontario Canada Posts: 1,813 Thanks: 842 Thanked 911 Times in 576 Posts Mentioned: 43 Post(s) Tagged: 0 Thread(s)	DI seals? The Frozen North __________________ 2013 SWP BRZ sportech. 11.11sec@129.01mph, 511whp on e70. FullBlown base kit, FullBlown built 9.5:1 engine, GTX3076R GEN2 turbo, 1700cc Bosch injectors, FullBlown flex fuel kit, FullBlown radiator and oil cooler, FullBlown custom 3" dual exit exhaust, act xtreme clutch, whiteline diff and subframe inserts, BC Racing coilovers, hotchkiss 18mm rear sway, is300 3.73 differential ... Never finished

04-09-2014, 03:34 PM	#10
Reaper in orbe terrum non visi Join Date: Jan 2014 Drives: violent Location: Mountains Posts: 1,747 Thanks: 279 Thanked 762 Times in 446 Posts Mentioned: 62 Post(s) Tagged: 1 Thread(s)	I think that was csg? I dont remember his full name Sent from my SAMSUNG-SGH-I747 using Tapatalk __________________ I have E85 where there isn't E85, that's my secret. http://www.ft86club.com/forums/showt...t=reaper+build

04-09-2014, 04:37 PM	#12
nelsmar Senior Member Join Date: Feb 2013 Drives: FR-S Location: Phoenix Posts: 2,605 Thanks: 733 Thanked 2,361 Times in 1,031 Posts Mentioned: 345 Post(s) Tagged: 3 Thread(s)	Log with equivilance ratio requested afr. And fuel system status. Sounds like you are running in closed loop with bad injector scaling and maxing out fuel trims. Post any logs you have for is to review and I sure we can figure it out. __________________ When I grow up, I wanna be God. My flickr - *Canibeat* Local magazine scout Old Setup: Vortech Supercharged 360WHP/262WTQ @ 11.5psi My build thread - WTF happened to nelsmar's car thread

04-09-2014, 07:10 AM	#3
Reaper in orbe terrum non visi Join Date: Jan 2014 Drives: violent Location: Mountains Posts: 1,747 Thanks: 279 Thanked 762 Times in 446 Posts Mentioned: 62 Post(s) Tagged: 1 Thread(s)	e85?

04-09-2014, 02:15 PM	#8
No Limit Motorsport Senior Member Join Date: Jul 2012 Drives: 2013 DGM BRZ Location: Long Island, NY Posts: 2,266 Thanks: 355 Thanked 406 Times in 228 Posts Mentioned: 27 Post(s) Tagged: 0 Thread(s)	Check your spark plugs, and also for vacuum/boost leak.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
I keep breaking lug studs!!!	Guff	Issues \| Warranty \| Recalls / TSB	59	12-30-2015 01:34 AM
Breaking-Bad SWP Build	mwjcyber	Member's Car Journals	7	02-17-2014 09:12 PM
Down hill breaking... ABS?	shaofis	Issues \| Warranty \| Recalls / TSB	11	10-22-2012 05:28 PM
Breaking Bad: Season 5	\|-Goku-\|	Off-Topic Lounge [WARNING: NO POLITICS]	15	07-22-2012 02:02 AM

User Name		Remember Me?
Password