Boost PE maxed out and still lean.

[2000C-5]

Specs:

- '05 vette LS2, w/E40, 6 speed man.
- 404 c.i. forged
- Procharger @ ~12 psi
- 235/242 614/624 115 lsa
- 60# injectors
- 2.5 bar OS w/2.5 bar MAP (with proper info)
- twin walbros, returnless system


Car idles good at 850 rpm, no surging, etc. My problem is I am maxing out the Boost VE around 130 kpa. I should make boost up to about 175 kpa. Hopefully I am just overlooking something.

At the same time I built the motor, I also changed it over from an A4 to a 6 sp. manual. That is why it shows automatic parameters.

~Tim



I included my config file I am using. I have my wideband reading through the A/C high pressure.

[Google]

whats your inj duty cycle? looks like your in need of bigger injectors.

[2000C-5]

whats your inj duty cycle? looks like your in need of bigger injectors.

I thought at first that was my problem, but the boost VE is maxed out even at low duty cycles.

I bought the Procharger used and I asked if the 60s were big enough. He said that he had plenty left over. I never asked and he didn't mention that he was running meth, so I have a meth kit on the way with a 12 gph nozzle.


I forgot to mention that I also have twin 255s in the tank.

[Google]

what injectors?

[2000C-5]

what injectors?

Siemens

[backchannel]

curious as to the 1.24 multipliers in IFR vs voltage and IFR vs IAT.

[2000C-5]

Because of the 63# IFR limit in the E40. Most likely it does nothing, but at the same time, it doesn't hurt to have it in there.

[Google]

the only time i have seen something like this is when it's a lack of fuel. did you put on new fuel filter or blow through the old one yet?

[DSteck]

Because of the 63# IFR limit in the E40. Most likely it does nothing, but at the same time, it doesn't hurt to have it in there.

You are correct in thinking it does nothing.

I can't see your log since I don't have HP Tuners at work... but describe what's happening. Is it leaning out at 130kPa, no matter how high you push the VE? When I did a Procharged TBSS with an E40 and the custom system, I had to scale it to avoid hitting the airflow limit (~67 lb/min).

[backchannel]

You are correct in thinking it does nothing.

I can't see your log since I don't have HP Tuners at work... but describe what's happening. Is it leaning out at 130kPa, no matter how high you push the VE? When I did a Procharged TBSS with an E40 and the custom system, I had to scale it to avoid hitting the airflow limit (~67 lb/min).

That was why I was asking about the multipliers-any effect on scaling?

[DSteck]

That was why I was asking about the multipliers-any effect on scaling?

No matter what, the injector flow is going to get capped out at 63.5 lb/hr.

[backchannel]

No matter what, the injector flow is going to get capped out at 63.5 lb/hr.

I got that. Wondering if those multipliers can affect ve table.

[5_Liter_Eater]

One problem could be that you have both the IFR VS IAT and IFR VS Volts at 1.24. I would recommend setting those back to 1.

But the MAIN problem is that you have P0101-P0103 set to "2 - No MIL Light". So you're not setting a P010x DTC so the MAF is not failing so you're not even referencing the VE tables. Set all three of these to "0 - MIL on First Error" and leave the SES enable checkbox cleared. Then the MAF will fail and you'll use the VE tables.

Here is my tune which is for a very similar setup. '05 vette, E40, ~12#, 60# injectors, twin Walbros + meth. Just a smaller cam and less cubes.

[2000C-5]

the only time i have seen something like this is when it's a lack of fuel. did you put on new fuel filter or blow through the old one yet?

Under normal driving I am only running one pump. The second pump is on a Hobbs switch set to come on at 5 psi. Each pump has it's own filter and this setup is brand new.

It is also doing it at low IDCs. Here is a section of a scan where is is doing it at ~130 kpa, at ~50% duty cycle.

You are correct in thinking it does nothing.

I can't see your log since I don't have HP Tuners at work... but describe what's happening. Is it leaning out at 130kPa, no matter how high you push the VE? When I did a Procharged TBSS with an E40 and the custom system, I had to scale it to avoid hitting the airflow limit (~67 lb/min).

Exactly. I have the BE set at the 4096 limit from 130 kpa up and it is still lean.

I have read where others have done this without scaling, but it is looking like that is my only option. If I scale say, 50%, is this going to allow me to run a MAF? (I have an LS7 cartridge style MAF)

One problem could be that you have both the IFR VS IAT and IFR VS Volts at 1.24. I would recommend setting those back to 1.

At one point I did set these back to 1, but it didn't seem to have any affect.

But the MAIN problem is that you have P0101-P0103 set to "2 - No MIL Light". So you're not setting a P010x DTC so the MAF is not failing so you're not even referencing the VE tables. Set all three of these to "0 - MIL on First Error" and leave the SES enable checkbox cleared. Then the MAF will fail and you'll use the VE tables.

Here is my tune which is for a very similar setup. '05 vette, E40, ~12#, 60# injectors, twin Walbros + meth. Just a smaller cam and less cubes.

My bad, I was thinking that "No MIL Light" would still set the code but just didn't give me the light on the dash. I did check at one point and I was getting a P0102 code but that was way early on and no telling what I have changed since then.

The picture above seems to confirm what you and DSteck are saying. The MAF is pegged at 67.72 where the problem starts even though my IDC is only 55%. So even with the the Dynamic Airflow set to 8192 rpm it is still trying to reference the MAF?

I will set the DTCs correctly and reference your tune and go from there.

Thanks everyone for your suggestions. I'll post back up my results either way it comes out.

[DSteck]

Sounds like you aren't failing the MAF properly. Set those codes to 0, and make sure your MAF fail frequency is zero. Then let's see what happens. If you see your dynamic airflow peg out at 67.something, then you need to scale for airflow.

[2000C-5]

Sounds like you aren't failing the MAF properly. Set those codes to 0, and make sure your MAF fail frequency is zero. Then let's see what happens. If you see your dynamic airflow peg out at 67.something, then you need to scale for airflow.

You're right, I wasn't failing it properly. I set it to "No MIL Light" instead of "MIL on first error".

I have it failed correctly now:







Even here, so it's dead. No screenshot, but I checked and I did have a P0103 code.




But........I still have the issue and what's odd is, it is still doing it in reference to the MAF. In the picture below the MAF has just pegged at 67.72 but the Dynamic Airflow is 45.19. This is the exact point that it goes lean. Tomorrow I am pulling the damn wires out of the connector.




That will get rid of the MAF, but i guess it won't cure my problem since the Dynamic Airflow will peg out and cause the same symptoms. So do I have to scale the entire tune or just certain Airflow parameters?

[DSteck]

I think your wideband is probably a piece of crap, because your injector pulsewidth isn't dropping out and your narrowbands aren't seeing the lean spike either.

[5_Liter_Eater]

I tend to agree. It looks like its all over the place. What is the scale for that graph?

BTW, You should be logging VE Airflow instead of dynamic airflow.

[DSteck]

I tend to agree. It looks like its all over the place. What is the scale for that graph?

BTW, You should be logging VE Airflow instead of dynamic airflow.

If he's actually in speed density, then he can log dynamic airflow and it'll be fine. Ultimately, the PCM is using dynamic airflow anyway, regardless of whether it's full MAF, full SD, or hybrid.

[2000C-5]

I think your wideband is probably a piece of crap, because your injector pulsewidth isn't dropping out and your narrowbands aren't seeing the lean spike either.

While it is a good wideband, I agree that it has issues. The narrowbands don't even flinch at any of the WOT spikes. Also where the AFR is showing commanded at 14.7, the narrowbands are in the low to mid 900 mv range when they should be around 450 mv. I had this same wideband in my 2000 model and it was flawless, hopefully it is just a wiring issue.