Z31 Twinturbo ECU tuning...

Klauss · Post by **Klauss** » Mon Oct 05, 2009 7:03 am

Hi, so I havent much time but I am now finishing my car.

Z31 VG30T
2x Garrett T3 stock Z31 turbochargers
Siemens Deka 750ccm Injectors
Stage 2 JWT cams
Pathfinder intake
Cobra MAF
Custom Exhaust + Intake
MSD Ignition Coil - only replaced original

So I made first steps to make engine running with my new setup.

Engine is running with 14,5-14,9 idle AFR.

I havent now connected Innovate wide band O2 sensor with nistune, but I have whole innovatech LM1 unit.

Engine is running good until FULL THROTTLE. When I hit full throttle engine lost power and combustion isnt good. So I made log from engine run and If someone can help me with this problem.

When I accelerate rpms slowly there isnt problem...

So when I was looking into log I found massive Ignition timing drop when i hitted pedal to the metal

so I am thinking that if load and rpms are higher so advance must be higher too, or I am wrong???

Until 4000rpms there is 40deg but in 4000rpms it is changed to 20deg, but to 4000 engine is running nice from 4000 isnt running good and good is nice word.

I tried change ignition timing table and no change. So If I can ask you for help, which table I must change it will be nice.

I havent now saved in notebook my binary file and it is almost original Z31 1987 Turbo bin, only cobra maf setup, injector change, proper K constant set and I want tune up injection table, but this rpm issue is now problem.

Thanks for advice.

Matt · Post by **Matt** » Wed Oct 07, 2009 1:24 am

looked at the logs and see @ 1:40:137 where you floor it

MAF stays steady but TP/injection time start dropping (leaning) and then MAF drops and RPMs start timing down and then it dies

Can you post your BIN file here so I can look on the bench

Would be nice to have AFRs in this log from the LM-1 so we can see what is happening with those too

Klauss · Post by **Klauss** » Wed Oct 07, 2009 3:13 am

Thank you.

So I made some more test when I was downloading BIN file.
Dont be scary when you will see BIN is little mess. So my problem is happening
only when engine is warmed up. Until aprox 70-75 degrees of celsius there isnt problem floor it. Problem is only when engine reach operating temperature.
Maybe it can help. Thank you for help

And I was looking on AFR when engine stop working correctly and AFR goes to 8-9:1. So it is looking too rich.

I will be thankful for any advice. Starting, warming up and other things works very well. Idle AFR is around 14,5:1 without O2 sensor connected. I will work on
conection between LM-1 and Nistune for AFR logging. But winter starting there so weather isnt ideal for this.

Matt · Post by **Matt** » Sat Oct 10, 2009 12:24 am

looks like you have a A32 AFM selected in the VQ map instead of the Cobra - would this be causing problems for you at all?

also the ROM image isnt merged so I've fixed that up (attached)

doing a maptrace on the log file I see that once you go over 2000rpm then the airflow kind of stays steady and the TP gets pulled right back

Given that the airflow going into VQ map and the TP is determined as a result of the VQ map then it would make sense if the wrong VQ was selected that is why you are getting these problems?

Get your AFRs right with the attached file and see how that goes

Klauss · Post by **Klauss** » Sun Oct 11, 2009 2:44 am

hi, so as you said there was Z32 VQ map, so i used your BIN file and engine is now working in different way.

If I read nistune manual right, I start with finding K constant for new setup.
So O2 sensor disconnected, engine warmed up ( if it is possible ), Fuel Injection map in Filtered value set to 0 in closed loop area. I did it and find K conatant = 66 ( AFR in idle 14,3-14,7 ) so I think this is right. Engine is idling well, AFR is good, nothing wrong.

When I want rev up AFR is lean so for engine isnt possible rev up. I changed values in columns and engine is reving up good. Without 4000 rpm problem.
It was only for stationary test, so I used same numbers in large number of columns. But for low load there must be big number in table, or AFR is really lean. BIN included, if you can look. Log included too.

So I dont know how make almost left half of FUEL MAP set to lower numbers as numbers in original fuel map. Not same but not 60-80 it is too much or not? Becasu MAP allow only 0-128 i think these are high.

I didnt try run with car, because I want to know if it is normal. I think it isnt normal.

Is there any other table which can affect this? I tried FUEL LOAD SCALE RPM table and other without success.

From one problem to another

MAF question I want buy this MAF : http://cgi.ebay.com/ebaymotors/2001-04- ... ccessories

Can I use Lightning 700HP VQ map for this MAF?

Matt · Post by **Matt** » Sun Oct 11, 2009 4:39 pm

the numbers on the fuel map are too big, like you are overcompensating for something else wrong to get it running

if you set the entire map to 0 then how does it read through the rev range? or does it lean out as it gets higher

scaling only affects where abouts the fuel map is accessed, you should not need to change this

the VQ map is the translation from airflow to TP indexing on the fuel map and this is multiplied by K constant

If the VQ map is wrong then you wont get close to 14.7:1 as you go through the map and if the K constant is wrong then it will read too high or low over the whole map until fixed

if its rich /lean only at the lower end then latency can adjust this if the rest of the rev range shows around 14.7:1

cobra MAF should be okay with the VQ map I think... we got these maps from Z31 owners who had previous used JWT ECUs

Klauss · Post by **Klauss** » Sun Oct 11, 2009 9:12 pm

Point something is wrong was good

You said it looks like VQ read and K constant problem.

When was VQ from Z32 and Cobra MAF engine was running much better then Cobra VQ map and Cobra MAF together. So I was thinking about what if and I started comparing VQ maps, so i found that Lightning VQ map is really similar to Z32 map but complete different from Cobra. So I tried use Lightning VQ map and voala, K constant can be much higher about 140 for start is good, idle AFR stable 14,5 and I can rev up engine without problems.

Problem over 4000rpms disappear too, so I made some tests and tried car on the road.

Engine is running without problems, no shaking, no twitch and over 4000 rpms on the second gear are rear tires spinning, so it looks promising now

Thank you for idea and maybe I have Lightning maf instead of Cobra or VQ maps are switched...But I was buying Cobra Maf but I dont know differences between these two so who knows. You can only check if maps are correctly in nistune software.

but BIG THANKS for help and ideas, because I was little unhappy until now.

Now it want tune up Fuel map against AFR, but car is running good now so it is good way I think.

If you can look on log and write me some advices I will be happy...

My bin file can be used for start with tune up Europien Z31 some US bins are not working for me.

Thank you Matt.

Matt · Post by **Matt** » Sun Oct 11, 2009 10:19 pm

good to hear you got it working. its been a while, firstly when you were using the Vein Pressure converter a while ago

just make sure your boost AFRs are right with that fuel map and checking for knock and should be all good. I cant see them in the log you will need to check on your end

Klauss · Post by **Klauss** » Sun Oct 11, 2009 10:26 pm

Matt wrote:good to hear you got it working. its been a while, firstly when you were using the Vein Pressure converter a while ago

just make sure your boost AFRs are right with that fuel map and checking for knock and should be all good. I cant see them in the log you will need to check on your end

Yes, VPC wasnt good working, nice idea but after complete redone of inteke manifold MAF is for Z31 ECU better solution.

Do you think if I will can use Lightning VQ map from Nistune for this MAF?

http://cgi.ebay.com/ebaymotors/2001-04- ... ccessories

I have now Cobra maf which isnt mine actually, so I want this unit.

What you think? Or If you can tell me which I should by for Nistune Lightning VQ map...

Matt · Post by **Matt** » Sun Oct 11, 2009 10:57 pm

I *think* you should be okay there. Its fairly cheap in comparison with the $370AUD Z32 MAF I bought so I dont think you can go wrong. As long as the VQ map we have there matches you should be okay

Klauss · Post by **Klauss** » Tue Nov 17, 2009 4:04 am

I am finishing ECU tune, almost everything is working well, ride with car is amazing, only clutch as I am saying in other post, it cannot handle increasment of torque.

Idle is running AFR 14,5-14,8 , I think because of JWT C2 cams are installed it is good. Idle is little unstable 680-780 rpms, but I think it is normal.

Only what I am fighting is when engine is warmed up and aprox 20s after start is AFR around 17-18:1 but after 20s is AFR 14,5-14,7:1...

So I tried find if some table must be change for this...I tried edit "After start enrichment, First time enrichment or Warm start enrichment" but without good result.

Can someone tell me which table can solve this problem. It isnt big problem, but I want solve this

Thx

Matt · Post by **Matt** » Wed Nov 18, 2009 11:10 pm

I'll have a look into it. On my R31 I'm having the AFRs drop to 18-19:1 when the airconditioner is used

So during the middle of a heat wave when idling, I have to turn off the a/c to stop it almost stalling!

Gotta check the FICD but suspect something else

After you start the First time injection is used and gradually ramped down, then it stops using it. I dont think there is a table, perhaps a constant. I'll have a look next time on mine. Try increasing TTP min to get around the issue