13B fuel problems

[kenjamin]

Hello,

I’m in the middle of tuning my FD Rx7

tuner is concern everything on the fuel seems a little too high.

It’s on G4X
1050 ID primary 2000ID secondary
IGN-A1 coils 
EFR 8374 IWG with Turblown shorty manifold
CAN lambda sensor
BUR9EQ spark plugs

 

Were running into an issue that the car is requiring more fuel. 15% more fuel than we expect everywhere. 

We swapped out the primary to another 1050ID. It decreased our fuel to normal amount. But it seems it taking us back to before (15% more fuel across the fuel map)

EGT (CAN TC) shows normal.

 

Thoughts currently, BNIB 1050ID is not flowing at 1065CC at rated pressure or ECU/ Injector 12v reading maybe off ?

Any thoughts and ideas of a way to troubleshoot? Thanks

Log and tunes attached.

Ken Rams high VE.pclx Ken Rams high VE.llgx

[Adamw]

It doesnt look a million miles away from what I'd expect really, when you say 15% more than you expect, what are you comparing to?

A couple of suggestions:

• Turn off IAT trim - the charge temp approximation is used to correct for the air density.
• Copy the example charge temp table in the help file.  
• It looks like the sec/pri flow ratio is set just on quoted flowrates, this will unlikely be correct.  To confirm you need to set the staging table to 0 so it is running only on primary injectors, hold the engine at medium speed, medium load, check the reported lambda, then set the staging table to 100% so it swaps to running only on secondaries, check the lambda again.  If the sec/pri flow ratio is correct then the lambda should be about the same regardless which injector is working.  If not then make a small adjustment and check again.  

What fuel is it running?

[kenjamin]

Hey Adam! 

The tuner was tuning a similar setup previous to my FD, noticed that every cell was noticeably higher. Previous FD idle was running with the cell in the range of 60–65% where’s mine is running 80-85% and thought something was off due to my FD being way leaner throughout the map than the previous FD. 

Okay I’ll try those suggestions out once I’m back on the dyno tomorrow. I’ll keep you posted. 
 

The car is running on 91 pump gas, with water meth kit. 
 

 

Ken 

 

[kenjamin]

Hey @Adamw

 

We did the check and notice both primaries and secondaries are 1 point off of lambda from each other.

 

We tuned yesterday again. Notice that the VE is much richer throughout the map which indicates normal VE levels 60-70%at idle and 80-110% during high rpm in vacuum (which follows the same trend as previous FD). After 2 hours of tuning, all seems to fall into place. Shut the car off and let it cool. Once we started up again. The car is now requiring more fuel (same as before 15% more throughout the map) which now we noticed the issue came back. 80-90% during idle and 110-130% throughout the rpm range in vacuum.

Now we’re scratching our heads.

-We followed the charge temp table from the help file

-Tuner tried only running each primary and secondary by itself and notice it was both 1 lambda point off from each other.

-We calibrated the MAP

 

-We then change the primary injector flow rate at rated pressure from 1065cc/min to 930cc/min which brought the VE percentage low at idle and once we rev the car to check the other cells in vacuum it cause everything to run richer. Which my tuner said it’s doing the opposite. 
 

I’ll upload the log once the tuner sends em over. 
 

Thanks

[dx4picco]

Having reduced the injector flow, the ecu think it is injecting less fuel. So for the same VE it is indeed richer. 

The following is that you need to reduce VE to come back to a leaner afraid. 

Where is you IAT sensor located? 

[David Ferguson]

If you are tuning on a dyno (or free-reving in the garage), how good is the exhaust extraction?  You can get fooled if the intake air has some exhaust in it.  You will tune leaner to get the same O2 content in the exhaust, but when real fresh air is supplied, it's now too lean, and needs to have fuel added.   

[kenjamin]

Yes, but the issue of what we’re having is the fact that the VE throughout the map is stating that we’re 80-90% at idle and 90-130% 

 

My IAT is a IAT1-8 from link and it’s sitting at the stock location. Under the upper intake manifold.

 

We’re on the dyno, where the exhaust is ventilated out.

 

Ken

 

[DerekAE86]

I am not sure your primary injector spwa settings are correct. looking at the id website it looks like the 2017 dated data was used but the newer 2018 dated data is actually different.

[kenjamin]

There’s 3 1050ID files

2 of which is from 2017

and the one from 2018 says it’s a model: G4+

Which one would be the optimal setting for 1050cc ID ?

Ken

[DerekAE86]

Doesnt matter that it says G4+. All you're looking for is the data that lines up to the pre-defined SPWA table within PCLink.

The other FD your tuner recently did - was it also using the exact same injectors?

[kenjamin]

Ok I see,

That I I don’t know. All I know was their cars were built in back in 2020 or longer.

I got these injectors we’ll over 2 months ago.

I could ask on Monday once I’m back at the dyno again.

 

Would the SPWA numbers being off cause an intermittent lean/rich across the map ? 

interesting find @DerekAE86

Ken

[DerekAE86]

42 minutes ago, kenjamin said:

Would the SPWA numbers being off cause an intermittent lean/rich across the map ? 

SPWA won't cause any issue at high load areas of the fuel table. but in the idle range where you don't want to inject much fuel at all it can make a difference to what the ECU thinks is going in vs whats actually going in.

"Intermittent" changes of fueling across the entire range would be something else. I'd lean more towards Air or Coolant temp corrections having too much (or little) influence so the modelled fuel equation is over or under compensating.

Either that or your O2 sensor is iffy. I assume the tuner has a sensor connected to the dyno that he's stuck up the exhaust pipe?
If they're confident that sensor is good - how close does the one in your car read to that?

[kenjamin]

Okay, I see 

Looking at the SPWA between the 2017 and 2018. If accidentally using the 2017 instead of 2018, wouldn’t it give us a richer condition ? Because as an example in the graph of 2017 at PW at 0.125 the adder is -0.013 where as 2018 PW at 0.125 the adder is -0.041. Which if we use the 2017 data the injector will open longer since it’s subtracting less than the 2018 data ?

 

Tuner actually turned off IAT correction and followed the charge air temp table from help file. He said it did not change nor fix the issue.

 

No the tuner does not have O2 sensor connected to the dyno. Just referencing off the CAN lambda from Link.

 

Ken

[Adamw]

19 hours ago, kenjamin said:

We tuned yesterday again. Notice that the VE is much richer throughout the map which indicates normal VE levels 60-70%at idle and 80-110% during high rpm in vacuum (which follows the same trend as previous FD). After 2 hours of tuning, all seems to fall into place. Shut the car off and let it cool. Once we started up again. The car is now requiring more fuel (same as before 15% more throughout the map) which now we noticed the issue came back. 80-90% during idle and 110-130% throughout the rpm range in vacuum.

Do you have a log of each condition to compare?

[DerekAE86]

11 hours ago, kenjamin said:

No the tuner does not have O2 sensor connected to the dyno. Just referencing off the CAN lambda from Link.

This doesn't sit well with me. All dyno's I've been to have a O2 sensor independant of the car's fitted one.

You could be tuning off bad Lambda data without even knowing it.

Did you use the included brand new LSU4.9 sensor with the Link CAN Lambda or are using a cheaper or old sensor?

How long has the car been sitting with Key on Engine off with this setting enabled?

[kenjamin]

I see, 

Ill inform my tuner on Monday. Also I can get the log and tune as well.

I installed the new LSU4.9 sensor with the link LAMBDA.

 

Run when stalled is left to YES since we started tuning. That I’m not sure ?
I know sometimes we could key on for a couple minutes and or start the car right away.

We don’t accommodate for the sensor to heat prior to engine starting.

I asked the tuner if I should we have turned it off. But he informed that it wouldn’t make a difference in AFR reading if it’s YES or NO for running when stalled. 

[DerekAE86]

If its the brand new sensor that came with the CAN Lambda unit and its only been set to Yes for this tuning session it's probably fine.
I'd be sus on it if it was a cheapy ebay sensor or its been set to "Yes" for many many hours of Key on Engine off.

But without a means to confirm the reading is accurate you're still kinda taking stabs in the dark.

[kenjamin]

Injectors got flow tested and came back to be 910cc. way below the actual flow rate of 1050cc

notice also that my fuel pressure sensor is erratic. But nothing crazy but fuel pressure will drop to 5 psi during high rpm.

I’ll post a log soon when I can