Tuner could not fix poor idle.

[Rosh9]

Hello,

I have a 1996 Ver.4 WRX. It has the original EJ20k motor which ran well on the factory MAF set up but drives relatively poorly on speed-density. When switching to speed density, I also opted for ID1050x injectors, radium rails, 3-port boost controller, DW255 pump and an AEM wideband wired into the G4X. It made 247awhp after being pro-tuned on a hub dyno.

Issues:

-The idle dips below the target rpm values and recovers often when clutching in or coming to a stop.

-Severe issue with top mount intercooler heat-soaking the IAT. If the car is idling in traffic or hot starts, it will begin to run more and more lean. The high IAT values persist even when moving with marginal improvement. I may try removing the intercooler to flush it out in case there is a layer of oil on the sensor. I'm confused why my wrx can't handle a top mount IAT location. 

-Car occasionally stumbles/hesitates hard when accelerating WOT.

-Extremely rich cold start with weak idle.

-Car also bucks on decel in gears 1st,2nd, and 3rd gear. I think its more to do with drivetrain slop than engine tuning but wondering if its possible to reduce through the tune.

 

Guesses about cause:

-Could the IACV be wired backwards?

-Is the charge temp table set up correctly?

-Main fuel / warm-up enrichment table look reasonable?

 

I uploaded the tune I'm running along with some log files.

https://drive.google.com/drive/folders/1Br4WCLON1kLUO2zlzIu-I_jo5MRV-YR9?usp=drive_link

 

Thanks for the time,

Rosh

[remski2]

Hi.  

There is no knock enabled.

CLL is on but its configured not to do anything at any time.. even at idle.. ???

 

You are running lean pretty much all the time..  I dont see any point at which the target AFR is met. 

(you could have developed a leak in your exhaust and now it reads lean all the time or you have a leak on the intake side)

 

Your coils are 3ms (stock) and its set to 3.8.. while notmuch..  you are constantly ovedriving and shortening the life span.. (sometimes its beneficial to run higher but usually its only for a short time ..not all the time)

 

Injector data looks a bit off as well.. 

 

It almost looks like the tuner forgot to save the changes..

 

My 2c... 

[Rosh9]

1 hour ago, remski2 said:

Hi.  

There is no knock enabled.

CLL is on but its configured not to do anything at any time.. even at idle.. ???

 

You are running lean pretty much all the time..  I dont see any point at which the target AFR is met. 

(you could have developed a leak in your exhaust and now it reads lean all the time or you have a leak on the intake side)

 

Your coils are 3ms (stock) and its set to 3.8.. while notmuch..  you are constantly ovedriving and shortening the life span.. (sometimes its beneficial to run higher but usually its only for a short time ..not all the time)

 

Injector data looks a bit off as well.. 

 

It almost looks like the tuner forgot to save the changes..

 

My 2c... 

Thank you so much for taking the time to reply.

I'll check for exhaust leaks.

I'll try to figure out if the knock sensor is wired in so knock control can be turned on. It's a plug-in ECU so I think it should be connected.

CL lambda being off makes sense why the car doesn't want to adjust fueling much when it's lean. I'll try to figure out setting that up.

I'll turn down the coilpack values too. 

[Adamw]

Do you have a copy of the map that was running the car at the time these logs were taken?  There are quite a few things I noticed in these logs that show different values than are set in the map so its hard to suggest changes when we dont know what settings were used. 

Im a little suspicious of the tuner with the issues you raise as it appears a lot of them are related to really basic tuning fundamentals. 

Anyhow, a couple of comments to think about in the meantime:

• You have both IAT trim and charge temp approximation enabled, it should only be one or the other. This will be the cause of some of the enleanment when hot.  Disabling either one now is going to affect the tune quite a bit so its going to need some re-tuning.  The charge temp table looks too biased towards coolant temp in my experience so I personally would copy the charge temp table out of our V11 base map as a better starting point and turn off the IAT trim.  
• The hesitation during acceleration is most likely accel fuel related.  However, the log shows there was no accel enrichment working at all whereas the map shows some extremely excessive accel enrichment set-up, so it seems someone has since changed that.
• Im not sure I trust the lambda reading, it could be a vacuum or exhaust leak as Remski suggested, a dying sensor, or possibly a wiring issue, but its sitting pegged at 4.5V a lot of the time so the AEM device is measuring it even "leaner" than it shows in the log.  There arent too many engines that would even run leaner than 1.25lambda so that doesnt seem to be reporting reality.
• Is the MAP sensor really a Link 3Bar?  
• There is no cold start log to verify the "extremely rich cold start and week idle", but the main things that look out of place here is the precrank prime is about twice as long as I normally see for a 1000cc injector, the post start hold is about 5X longer than normal, and post start decay is about 2X longer than normal.
• The bucking is likely coming from the over-run fuel cut ramp in/out being too abrupt.   I would usually have more retard (15-20deg), and about 1-1.5s torque reduction/introduction time.  You also need to be mindful of the ign table cells that are being referenced as you typically enter and leave ORFC.  Secondly, you have idle control speed lockout set to 25kmh so you may have idle ign kicking in/out when not expected in some situations.  
•  The idle dip is due to either the dashpot settings or base position, but again the log shows different values for both than what is currently set in the map so we really need a log and map that match to make a suggestion.  
• You are on old firmware also, so it would pay to update to the latest to get all the improvements that have been made in the last couple of years.  Download the latest G5 software and use that to do the update.