stuttering problem with logs

[mac 108]

Here are two logs, -20% Correction across the board

Log 1
TIMA O2-R TPS MAFS RPM KNCK INJP
29° 0.12V 25.5% 188.7Hz 1969 0 3.84ms 8
29° 0.37V 25.5% 201.3Hz 2031 0 4.10ms 8
29° 0.70V 25.9% 207.6Hz 2094 0 4.10ms 9
28° 0.06V 38.4% 251.6Hz 2156 0 5.38ms 12
25° 0.76V 65.9% 339.7Hz 2375 0 6.66ms 16
24° 0.86V 69.0% 402.6Hz 2688 0 7.17ms 20
24° 0.88V 70.2% 522.1Hz 2969 0 8.70ms 27
24° 0.88V 73.7% 629.0Hz 3156 0 10.75ms 36
22° 0.88V 84.3% 767.4Hz 3344 0 13.06ms 46
18° 0.88V 88.2% ####### 3594 0 16.64ms 63
18° 0.86V 100.0% ####### 3906 22 19.71ms 82
11° 0.84V 100.0% ####### 4188 21 19.46ms 87
11° 0.84V 100.0% ####### 4250 21 19.46ms 88
12° 0.84V 99.6% ####### 4469 24 19.20ms 91
8° 0.84V 99.6% ####### 4656 30 17.66ms 87
9° 0.84V 100.0% ####### 4844 36 18.43ms 95
7° 0.82V 99.6% ####### 5063 36 17.41ms 94
8° 0.82V 98.8% ####### 5250 35 17.15ms 96
9° 0.82V 87.8% ####### 5344 42 15.62ms 89
7° 0.80V 9.8% 484.3Hz 4750 40 2.82ms 14
32° 0.78V 9.8% 100.6Hz 4781 7 1.28ms 6
44° 0.76V 9.8% 69.2Hz 4250 0 1.28ms 5
42° 0.04V 9.8% 50.3Hz 3813 0 1.28ms 5

Log 2
TIMA O2-R TPS MAFS RPM KNCK INJP

36° 0.70V 18.4% 119.5Hz 2281 0 2.56ms 6
35° 0.04V 23.5% 169.8Hz 2375 0 3.84ms 9
31° 0.74V 38.8% 295.6Hz 2531 0 5.12ms 13
26° 0.80V 39.6% 339.7Hz 2594 0 5.38ms 14
26° 0.78V 40.0% 371.1Hz 2688 0 5.38ms 15
25° 0.06V 48.2% 427.7Hz 2750 0 7.17ms 21
23° 0.84V 93.7% 540.9Hz 2969 0 9.22ms 29
23° 0.86V 100.0% 798.8Hz 3875 0 13.06ms 54
22° 0.84V 100.0% 1352.4Hz 4313 18 19.46ms 89
12° 0.82V 100.0% 1446.7Hz 4594 25 18.43ms 90
10° 0.80V 100.0% 1459.3Hz 4844 25 18.43ms 95
11° 0.80V 100.0% 1440.4Hz 4969 25 16.90ms 89
11° 0.80V 100.0% 1453.0Hz 5219 38 16.90ms 94
8° 0.78V 100.0% 1484.4Hz 5406 37 15.87ms 91
10° 0.78V 100.0% 1421.5Hz 5594 37 16.13ms 96
10° 0.80V 100.0% 1220.3Hz 5625 36 14.08ms 84
11° 0.53V 100.0% 1251.7Hz 5781 43 12.80ms 79
12° 0.00V 100.0% 1358.6Hz 5906 43 13.82ms 87
12° 0.00V 100.0% 1144.8Hz 6031 43 10.24ms 65
15° 0.00V 100.0% 1503.3Hz 6344 43 13.57ms 91
12° 0.00V 87.1% 1012.7Hz 6188 42 8.96ms 59
14° 0.72V 9.8% 415.1Hz 5188 35 1.79ms 9
35° 0.84V 9.8% 94.4Hz 4844 3 1.28ms 6
44° 0.82V 9.8% 69.2Hz 4313 0 1.28ms 5
42° 0.82V 9.8% 44.0Hz 3625 0 1.28ms 4
40° 0.53V 9.8% 37.7Hz 3500 0 0.00ms 0


FTRL FTRM FTRH
137.3% 97.5% 82.7%

15 PSI on an Evo 3 GT, full exhaust mods, walbro 255, AFPR, 650cc injectors, hacked MAS with K&N filter

I also have a stuttering/loss of power in the high RPM bands (usually 6K)

 

[kams1gsx]

Looks like you got some pretty gnarly knock going on.That stuttering you are feeling is your pistons detonating I have a similar problem,and have close to the same set up as you but in my case i got rich knock becauce of an exhaust leak before the o2.Its a good idea to turn the boost down until you find out whats going on,check for leaks

 

[->PrOjEcTGS<-]

You should have the capability of enough fuel for that setup. It looks like right around 4000 and above it knocks try richening it up a little from 4k on. Then post that log. If you notice on your O2 voltage it looks like your sweet spot is about .88-.87 anything lower than that and your knockin. That .78 is just unacceptable. Also, what is your base fuel pressure set at? You may want to up that about a couple psi. I always had mine set at 50 psi base. Try that and then post a log.

~Kletke~

 

[Joesmoke]

Big injectors with lotsa correction on the afc results in increased timing given by the ecu.
This in turn causes knock....resulting in yanked timing (12 deg). This is going to feel like the car is down on power (seriously down!), but not a studder.

If its cold in your climate currently, this will also let the stock ecu advance timing, so you you would be really fighting an uphill battle.

Solutions:
Take some base timing out to combat the -20 on the safc
Have a solution in place to adjust timing (piggyback-standalone)
Adjust the corrections up, to fight the advanced timing.

The studdering is not your pistons detonating. Assuming you have the stock ecu and KS in place, it will be very aggresive in preventing detonation. Detonation sounds like a low grumble. You will most likely never experience this with the stock safeguards in place, unless you pee in your tank and crank the boost through the roof. Even then, the stock system comes into play.

That high rpm miss/studder, is going to be a boost leak, or igntion related. Check/replace wires, plugs. Seal up leaks.

HTH
Jason

 

[Joesmoke]

And, just to prove my point, I had a very similiar miss/studder at around 6000 rpm. I just got back after installing a new set of wires, and its as smooth as butter all the way up!

 

[mac 108]

yeah I replaced the plugs with new NGKs, same problem, wires are next

 

[->PrOjEcTGS<-]

The stock MAS might be the problem too. I had a problem with my last 1g when I installed the Evo III 16g. It would get to about 15psi and the MAS would overrun. On your SAFC look at the MAS graph and see what it does if it goes all the way maxxed out it's probably overruning. I fixed it with the 2g MAS. Just another perspective.

~Kletke~

 

[mac 108]

Yeah I have a 2g MAS, I just haven't had time to install it.

 

[mac 108]

Changed the wires and the plugs. Boost at 10psi, stutters now at 4200 RPMs

New NGK BPR7ES .28 gap

New Bosch wires

base timing is stock (checked with timing light)

I don't understand how it got worse, car has also developed a miss. Fuel pressure 44 currently (I have played with this number quite a bit) with the car running and vacuum hose on.

I did use a timing light to check the timing. Grounded the computer then started the car on and checked it and it was fine.

Before I changed the plugs. It sputtered at 6k+ RPMs with no miss. I took at the plugs, checked the compression (disconnected coil connector and removed EFI fuse) I was 140-140-120-140 from passenger side to driver side. Yes it is getting close to rebuild time. After that I replaced the plugs with the .28 gap. Developed a miss, reinstalled old plugs, miss is still there. Reinstalled new plugs, still had miss and sputter at 4200 RPMs. Changed wires, no change, miss and sputter still there.

 

[mac 108]

Boost leak test revealed my problem: broken o-ring on my injector. It was the o-ring on the cylinder that had poor compression.