LiX

iTrader: (1)

Guys, I have a strange problem.

My car is Lancer 2008 with 4B10 engine. Modification are Takeda SRI, RA snorkel and custom Magnaflow Axle-back exhaust. MAF was rescaled for increased diameter of Takeda SRI and Injectors were scaled from factory 232 to 218 for more fuel to compensate the increased air flow.

I'm using EvoScan 2.7 for datalogging and EcuFlash to make changes to ECU. If EvoScan logs correctly, I'm making a lot of knock from low rpm.

When I make a 3rd gear pull, pedal to the floor, KnockSum starts to grow from 1100-1500 rpm, up to when I release accelerator pedal. And we are talking for 10-15 KnockSum. That's very strange because car accelerates normally and I'm completely confused...

I found that when I step on pedal sharply I'm making knock, according to EvoScan, that's on 2nd or 3rd gear. I don't know if that knock is real...

How can I be sure if that knock is real, what are the signs of knock? How you guys datalog knock on your cars?

LiX

iTrader: (1)

Guys, you are not helping me by not replying...

M@verik

Believe me u dont want some guys here replying to ur post lol. The best bet way to see if any knocking is happening is to open up the engine and check for unusual wear and tear on the pistons and valves. Otherwise another way (which needs a good ear) is the screw driver method. Place one point of screw driver above each cylinder with the other to ur ear and listen for any abnormalities. This also needs another person to rev the car to test it at different rpm's, but with a well trained ear, it is the easiest way to detect knock.

aspir3

You are wrong here. The best way to check knock is using Evoscan. You dont want it registering more then 9.

Lix I am no expert but I would think you need to look at your MAF maps.
What fuel are you running?
Have you altered high octane fuel or timing maps?

M@verik

He is already using evo scan Im giving non program related alternatives.

CamShaft

If you are getting engine knock, it is most likely pre-detonation causing this which is most likely to lean of A/F ratio. I would check your tune and go from there.

If it is knocking, your knock sensor (OEM) should be catching this, adjusting the timing to get rid of it, but since you changed the injectors, your EECU will try to compensate but may not be able to fix it due to the injectors being different. I am surprised if this is a regular occurrence it is not giving you a check engine light, or even drivability issues.

So after reading your post again, to me it sounds like the different injectors you have are providing too much fuel and your EECU is leaning it out until it knocks, then trying to get it back to normal. I suggest a full tune or a flash of the fuel map. Leaving it at stock fuel map with different injectors could be causing a problem. There are so many variables it is hard to say what your issue may be.

Good luck.

PS you should be able to hear it knock if you have a mechanical ear for this thing....I don't know about little engines but a big 15L diesel you can definitely hear it knock.

LiX

iTrader: (1)

I reverted back to stock air box setup and stock ROM and there is no knock, so knock with Takeda setup shoud be real.

When I put Takeda SRI and with stock ROM there is knock and after some time CEL comes on telling me that "System is too lean", so I should be running leaner with that setup. STFT was in upper range +12 and LTFT was around +6. I think that when STFT is constantly out of range -/+ 12 for some period of time, than CEL comes on.

Than I adjusted injectors to bring more fuel and STFT was negative at startup and max +8 at some moments. LTFT was max +3, but most of the time around 0, but not negative. Injectors were not changed, they are stock. MAF was also rescaled. After that intervention car is running better, no CEL light anymore, but knock is still there. Fuel maps were not changed. Retarding 2 degrees of timing in high load areas don't help. Still knocks.

Also I'm not seeing timing retard when knock occurs which is strange. I can post EvoScan logs if anybody want.

I think problem may be with MAF somehow...

CamShaft

11

CamShaft

Could be a MAF problem. I am a heavy duty diesel tech, so I don't know many of the acronyms you are using. All I have done to my car is a SRI and axle back exh. I do know a little with reading the function and design in the manual.

Is it a definite knock or ping that you can hear? or is it just the program you are using to sense it? Can you rely on the program? Is it giving you a false fault? Just a few question i thought I would throw out there. I am sorry I cannot help any further as I am limited to my knowledge of tuning gaspots.

LiX

iTrader: (1)

Just the program tells me there is knock and with stock setup the same program tells me there is no knock, so knock should be real. Otherwise no visible signs of knock - no lagging, acceleration is rapid and strong...

I assume there is knock, but for now I don't know why. I'm running now with stock setup and I'm collecting datalogs, so I can compare them with Takeda setup logs and figure out where are differences and how can I eliminate that knock...

Gtrkndagy

i had the same problem on my ride and it turn out that my valve timing needed to be readjusted. Just a normal wear and tear on some engines. My car was a corolla.

Green_Bandit

iTrader: (25)

Why aren't you logging knock voltage to see if it's real knock?

Decrease maf scaling a bit?