SR20DE 70J00 ECU

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martin7937
 

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SR20DE 70J00 ECU

Post by martin7937 »

Hi everyone,

I recently purchased another ECU with Type 3 board. Since then I've been trying to basic tune it for use in my daily P10.
The 70J00 ECU comes from one of the oldest EU P10s, using no o2 sensor and a 4 wire MAF.

My current setup includes P11 MAF and 370cc injectors.
When I open the stock bin for the 70J00 ECU, nistune detects N15-SR20DE-1N9xx (250 HP) VQ, stock K value is 31206.
After injectors resize from 270cc (using Factory CC button) to 370cc, K changes from 31206 down to 22771.
Later on when changing MAF to N15-1N4xx-P11-SR20DE (290 HP), K jumps to 26414.

So far so good. However, when I go out on the street to tune for proper K, in order to get 14.7:1 AFR I have to decrease the K down to 20000, which seems quite a lot.

Attached are the stock bin and the one ready for street adjustment of K.
Attached is also the log from adjusting K. It first shows 4th gear at almost low load, 2000 rpm and then slow acceleration to 3000 rpm, where at low load AFR is around 15.2:1.

Please someone take a look at them and let me know if he finds something wrong. Engine is not working smooth at all, hesitates a lot and shakes really bad. This is all present below 3000 rpm and up to 4th gear.

Thanks
Attachments
Adjusting K.csv
(140.13 KiB) Downloaded 91 times
04 - K.bin
(32 KiB) Downloaded 103 times
02 - Stock.bin
(32 KiB) Downloaded 95 times
bachig24u
 

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Re: SR20DE 70J00 ECU

Post by bachig24u »

After a quick look...
I Changed the fuel map and limits to more suitable levels.

This is by far a tune to go racing with but it should partially address the cruise issue.

let us know how you go, send another log through so we can compare differences.
Attachments
sr20lean issues04 - K.bin
(32 KiB) Downloaded 91 times
skylinegtrhr
 

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Re: SR20DE 70J00 ECU

Post by skylinegtrhr »

Did You put resistor on fourth pin?
martin7937
 

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Re: SR20DE 70J00 ECU

Post by martin7937 »

skylinegtrhr wrote:Did You put resistor on fourth pin?
No, I didn't because it is only the ECU that comes from no o2 SR20 P10. The ECU is now in a 93 P10, where stock MAF harness has 3 wires only. What I am trying to say is that I actually have no extra wire to worry about, or extra MAF pin since I am using P11 MAF which also has 3 pins.
bachig24u wrote:After a quick look...
I Changed the fuel map and limits to more suitable levels.
This is by far a tune to go racing with but it should partially address the cruise issue.
let us know how you go, send another log through so we can compare differences.
Great, thanks! I will run the bin during the weekend and come back with another log.
skylinegtrhr
 

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Re: SR20DE 70J00 ECU

Post by skylinegtrhr »

martin7937 wrote: No, I didn't because it is only the ECU that comes from no o2 SR20 P10. The ECU is now in a 93 P10, where stock MAF harness has 3 wires only. What I am trying to say is that I actually have no extra wire to worry about, or extra MAF pin since I am using P11 MAF which also has 3 pins.
ECU need resistor if ECU is from non catalyst car, MAF doesn't need resistor ...
martin7937
 

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Re: SR20DE 70J00 ECU

Post by martin7937 »

Understood. In that case the answer is no, I didn't place any resistor.
Do you know where I can find more information about this mod?
I can find the wiring diagram so to compare with the current harness and figure out the pin that needs to be tricked with a resistor.
skylinegtrhr
 

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Re: SR20DE 70J00 ECU

Post by skylinegtrhr »

Just measure resistance on old OEM MAF (which is pair with that ECU) and put that resistor between ground and ECU pin. I really can't remember what was resistance on customer car which also have no O2 sensor and it now have Z32 MAF.
martin7937
 

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Re: SR20DE 70J00 ECU

Post by martin7937 »

That would be a difficult one since the original car was recycled..
Anyway, I got the idea. I think I can find another P10 using that old 4 wire MAF.
Thanks for the advice!
martin7937
 

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Re: SR20DE 70J00 ECU

Post by martin7937 »

@bachig24u >>> I finally found some time to try the bin. Engine runs extremely rich and load scalers are way off, I assume due to the pumped K. Instead of running at 14.7:1 at cruise, AFRs are 12s. At idle engine often dies as it sometimes reads even 11:1.
Attached is the respective log.
Besides that, engine runs smoother. I decided to use the changes you made in TTPmin/max tables, together with the new values for the TP Limit table. Everything was disregarded.
As of now I am actually having a small progress. I ended up sorting most of the issues by simply making few changes here and there.
Probably in a day or two I will log my current bin and will post it. Most idle issues are gone, in WOT all mixtures seem to be close to what I was aiming at for a base, in cruise everything seems to be quite well as well, plus the engine no longer hesitates and shakes so much.

@skylinegtrhr >>> I can't find any other car using the same 4 wire MAF, thus I can not measure the resistance. I think I figured out what I should do - the 4 wire MAF has white wire, which goes to ECU pin 17, black wire, which goes to ECU pin 17, black/yellow wire, which goes to ECU pin 25 and orange wire, which goes to ECU pin 38/42.
Black is the ground. Orange is supply. It is either the white one or the black/yellow wire which which I don't have. My stock harness has 3 wires - ground which is white I think, signal, which is red, and the bigger orange one. I have to disconnect the ECU from the plug to see what pins are free and then I should be able to reground.
Attachments
NIStune_2013-09-17_1029_55.csv
LOG - sr20lean issues04 - K.bin
(203.61 KiB) Downloaded 105 times
martin7937
 

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Re: SR20DE 70J00 ECU

Post by martin7937 »

Please anyone, review my first post. Is it normal that I decrease the K so drastically to get 14.7:1.
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