Help with AF-readings. Stock Fuelsys. and 16g.

[Chris_Sag]

I have installed a AEM-uego and is running 16-17psi on a 16g (Xs-power).
When i floor it my readings is around 10,2-11,4-1 and the light is always on green. When daily driving the orange light is on and reading 14,1-15,7.
When idling the light becomes red and it lies around 17-1.

How is it possible that I am running rich at stock fuelsystem and a 16g running 16-17psi? Something must have been done to the car in the past?

 

[nightmares GS-T]

Good question. You very well may have a boost leak. Check and get back with us. All cars are different too though.

 

[Chris_Sag]

Possible to have a boost leak when i meassure the boost to 17psi on the intake? But Im pretty sure that is no leaks, tested it for a couple of months ago and it was Ok back then, and have not felt any difference of the car latley.

 

[92AWDHX40]

Do it again why not its so easy to do just because something was fine then doesnt mean its the same now.

 

[nightmares GS-T]

Do it again why not its so easy to do just because something was fine then doesnt mean its the same now.

Exactly. Do the test again on the turbo inlet not the tb elbow and test to 20 psi. If u hear any leaks use the soap and water method to find them.

 

[Chris_Sag]

Did the test but could not hear or see any leaks:S This is wierd?

 

[LiquidX]

You need to turn the boost down to stock wastegate levels. With your stock fuel system you are maxing out the IDC of your puny 450cc injects causing them to stay open. You are adding in too much air for what the injectors are spraying which is giving you a leaner pull and your injectors being at or above 100% IDC are no longer pulsing but all 4 are are constantly spraying.

This will cause damage and is a reason people need to log before turning up the boost.

Crusing in closed loop the ECU runs off of the front o2 sensor and tries to maintain a stoic mixture of 14.7. Open loop runs off of a fuel map and assume it's right. Your stock map for WOT is 9.5 AFR or so.

When idling you should be cycling 14.7 as well but since there is not load on the engine a 17 AFR won't do damage.

Perhaps try recalibrating the sensor and check for any exhaust leaks up stream from it. I k ow the flex section is a big leak spot over time which is why mine is in the front o2 location running narrow band simulation

At idle if there is a exhaust leak extra air will enter the system and it will affect the reading on the sensor.

 

[Fehrion_sit]

i got to agree with the wise man, stock injectors cant handle that kind of boost or abuse

 

[Chris_Sag]

i got to agree with the wise man, stock injectors cant handle that kind of boost or abuse

True that the stock injectors cant handle that boost, so i was wondering og of maybe they where changed in the past or something. Have tryed to turn down the boost but it will not go any lower. I think i have to port my wastegate. This is not a genuine 16g but "XS-power" replica.

You need to turn the boost down to stock wastegate levels. With your stock fuel system you are maxing out the IDC of your puny 450cc injects causing them to stay open. You are adding in too much air for what the injectors are spraying which is giving you a leaner pull and your injectors being at or above 100% IDC are no longer pulsing but all 4 are are constantly spraying.

This will cause damage and is a reason people need to log before turning up the boost.

Crusing in closed loop the ECU runs off of the front o2 sensor and tries to maintain a stoic mixture of 14.7. Open loop runs off of a fuel map and assume it's right. Your stock map for WOT is 9.5 AFR or so.

When idling you should be cycling 14.7 as well but since there is not load on the engine a 17 AFR won't do damage.

Perhaps try recalibrating the sensor and check for any exhaust leaks up stream from it. I k ow the flex section is a big leak spot over time which is why mine is in the front o2 location running narrow band simulation

At idle if there is a exhaust leak extra air will enter the system and it will affect the reading on the sensor.

But as long as my AF-ratio is ok why is this causing damage? Does it get way to mutch fuel at 100% IDC? To mutch fuel can also cause damage?

 

[nightmares GS-T]

Liquid just told you what's wrong man. Your injectors are maxing out and sprayig fuel nonstop which would be why your running so rich.

 

[Chris_Sag]

I understand that. But why is this dangerous? Tought running a bit rich was Ok.

 

[LiquidX]

You are running lean because your injectors are spraying nonstop because the turbo is flowing too much air. It is damaging to the injectors due to them not pulsing as thy should. You are spraying excess fuel into the cylinders that are not firing causing wasted fuel and with a possibility to backfire So techincly you are running rich and lean at the same time if that makes sense.

Point is, you need to turn your boost down to wastegate levels until you upgrade your injectors, fuel pump, and have a way to tune.

 

[Chris_Sag]

Fixed my wastegate and is running 8psi, but the AF reading is still the same? Is my injectors allready shot?

 

[LiquidX]

Did you check for exhaust leaks pre wideband sensor?

 

[BWeston]

You are running lean because your injectors are spraying nonstop because the turbo is flowing too much air. It is damaging to the injectors due to them not pulsing as thy should. You are spraying excess fuel into the cylinders that are not firing causing wasted fuel and with a possibility to backfire So techincly you are running rich and lean at the same time if that makes sense.

Point is, you need to turn your boost down to wastegate levels until you upgrade your injectors, fuel pump, and have a way to tune.

yeah, 16-17psi is a little much on stock fuel system. but you mentioned that you turned the boost down and you still are having the same problems?

 

[Chris_Sag]

No leaks, and still having the problem..

 

[92AWDHX40]

How are you tuning it?

 

[Chris_Sag]

No tune at all, but i dont know what have been done to the car before I imported it from US to Norway, but I think everything was stock until my T25 blew up, and i replaced it with the 16g. When that said as long as i had the car for two years the fuel consumption has been way to high for this kind of engine. Have replaced o2 sensors and FPR but with no luck..

 

[92AWDHX40]

Get a tuning device to help out, logger, dsmlink something so you can check codes, and see whats going on could be something simple or just throw things at it all day. Liquid did a good job of helpling.

 

[Chris_Sag]

You all did a greate jobb helping.. Thanks a lot...

 

[jed344]

im running 17psi with 14b and stock injectors without issues. but then again i have wally 255 and FFWD fuel kit so that might help with IDC.

 

[Absit]

I think a lot of you guys didn't read his post, he's not running lean in boost, he's running lean at idle. He's running fine in boost and cruise.

 

[MY1GDSM]

Basically to summarize what has been said and my thoughts on it if 7 steps... .
1: Do a BLT...
2ut a new Fuel filter on the car.
3:Turn your boost done some till you have a way to monitor you DC...
4:Check to see what kind of FP you have.
5:If planing on running around that amount of boost and can get away with it
you'll need at a minimum a 190lph PF.
6:Buy fuel pump
7: Raise boost back up watching Dc and stop @ 80%

theirs a few thing that I missed in their but you get the gist

I'm sure you can use common sense and Do the rest of your maintenance as well <---- Clicky before hand

 

[Chris_Sag]

Thanx, I dont think a new fuelfilter will help since im running rich and not lean, the rest of the maintainance is allready taken care of.. Is it a way I can see if my FP or injectors have been changed in the past? Without taking the hole car appart?

 

[Devilman]

it sounds like everything is fine in boost maybe a tad rich but thats safe-er
going lean at idle kinda sounds like a exhaust leak of some sort

how does it run at idle when its reading lean? does it start to jerk like the engine is about to die?