1jz fine till i hit 13 lbs of boost. little help pls.
10-01-09, 04:03 PM
#1
Pole Position
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: Arizona
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
1jz fine till i hit 13 lbs of boost. little help pls.
checked the coil packs, nothing visible(is there a particular problem area to look at on these?) , airfuel meter says im full rich under boost, never comes back toward lean at all when in full throttle, plugs are denso iridium gapped at .27, fuel pump mod done, car magically starts sputtering like its losing spark of fuel at 12.5 lbs of boost, 12 lbs, fine. 10 lbs fine, its not like a fuel cut like when cars hit boost cut as its not like a smack in the face loss of power, it just struggles like its missing all of a sudden, lift throttle a bit and it goes away. set boost at 12 lbs and i would never have to deal with it again. seems to be across the rpm band, as long as i am full throttle and boost goes to 12.5 or above i get sputtering.
10-01-09, 05:28 PM
#4
Pole Position
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: Arizona
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
well when the problem hits it def feels like a miss, it stops running strong like a light switch going on and off with the pedal pressure, full throttle at 13 lbs, miss, 3/4 throttle when miss is happening causes the miss to imediatly go away/. i had read your thread about the leaky bypass valve, however I am able to make enough boost to hit cutoff, but the car misses the whole time.
regarding denso iridium, not sure the age, pulled them and rgapped when problem first occured and they looked fine, suippose it couldnt hurt to swap them.
regarding denso iridium, not sure the age, pulled them and rgapped when problem first occured and they looked fine, suippose it couldnt hurt to swap them.
10-02-09, 05:05 PM
#7
Are you running a a/f controller (SAFC or sumthing?), cuss with just boost cut, it will start cutting up after about 13 with out some sort of controller. mine didnt show any problems at 15psi till it was too late A/F was all ways 10.5 and under. but the stock recerck valve was leakin past 12 ( i think some one already mention this) i had to replace it with a HKS BOV.
Trending Topics
10-02-09, 06:01 PM
#8
Pole Position
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: Arizona
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
well i have hit fuel cut when i first installed boost controller, it felt much different, it fell like an immediate cut in power, this feels like loss of one or two cylinders, and if i stay in it it will keep accelerating and boost will hold over 12.5 however it is missing. checked for leaks and found none. anyone know where to inspect coil packs for cracking? is there a common problem area?
10-02-09, 06:18 PM
#9
Pole Position
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: Arizona
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
when ur recirc valve was leaking did yoiur boost guage flutter around alot or did you just not build boost beyond a certain point? when this issue happens the boost reading will not hold steady and flutters rapidly about 1 lb in each direction.
thanks,
Kevin
10-02-09, 07:52 PM
#12
I have the same problem. 10-12psi fine, but when I full throttle, it hits 15-16 and it starts sputtering. I'm going to do a boost leak test and replace the plugs with one step colder. I'm running NGK coppers for the 2jz-gte, but I need something with a lower heat range. The spark is definitely blowing out.
10-03-09, 09:28 AM
#13
From my expereince with my turbo dsm. Check the pipes, sometimes if u buy universal pipes or crapy ones the lip or bead around the opening is small and wont hold coupling at boost. I welded a thick bead on mine and never had a problem. Also spark blow out may occur especially if your runnin denso iridium plugs ( i allways blew em out). Try NGK platinums and maybe go 1 or 2 steps colder since your FI. Also maybe your spitting too much fuel in at higher boost. Check your reading on your O2 and or exhaust to see how hot they are running. Lastley if all else fails i used water/meth injection and it allowed me to run 19psi on pump gas.
10-03-09, 02:23 PM
#15
Pole Position
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: Arizona
Posts: 249
Likes: 0
Received 0 Likes
on
0 Posts
swappe dstock bypass valve for aftermarket brand x bov that came with fleabay fmic, expensive it was not but it works as it should and it is CERTAINLY stronget than factory bypass valve, no change whatsoever. going to swap plugs, any recommendations? i live in sd so climate is pretty much 70 every day of the year.some really hot days are 80
