Runing out of fuel?

[gob4sho89]

Mods are in my profile... I am tuning with an AEM wideband and dsmlink v1. I am running 12psi of boost, and my injectors duty cycle is all the way up at 89%!!!WTF My fuel pressure is at 45psi at idle with the vaccume line disconnected. Air/fuel ratio is aroutd 10.1:1 - 10.0:1. Does this seem right? I just find it hard to believe that I am flowing enough ait to max out my 650cc fuel injectors at only 12psi.

 

[snowborder714]

Your fuel pressure should be 43.5 psi with the vacuum line disconnected (or just use DSMlink to turn the fuel pump on when the car is off so you don't have to disconnect the vacuum line).

 

[gob4sho89]

Thats where I had it at, but i was running out of fuel, so I turned it up a little. It didn't change anything, so I put it back to 43.5psi.

 

[snowborder714]

What do you mean by "you were running out of fuel"?

Have you done any tuning with DSMlink (like calibrating the MAS, adjusting the fuel sliders)?

 

[KYNgsx]

Mods are in my profile... I am tuning with an AEM wideband and dsmlink v1. I am running 12psi of boost, and my injectors duty cycle is all the way up at 89%!!!WTF My fuel pressure is at 45psi at idle with the vaccume line disconnected. Air/fuel ratio is aroutd 10.1:1 - 10.0:1. Does this seem right? I just find it hard to believe that I am flowing enough ait to max out my 650cc fuel injectors at only 12psi.

I'm not familiar with the turbo you're running, but my car ran around that same AFR and duty cycle back when I had 650's and before I did any tuning. 10.0 is pretty rich; you really don't seem to be running out of fuel.

 

[kahl23]

L2R is a bolt on 3076, kinda like a 3052. When I was asking around when upgrading to my 3052 I was told my 750s could handle up to around 24psi, so your 650s should be enough, try leaning it out, running an afr of around 11:1 or thereabouts and see if your IDC's don't drop. A log would also help things.

 

[gob4sho89]

I tried a bunch of things... If I go leaner then 10.2-1 I start to knock... I just installed 1150cc fuel injectors last night. I am having a hard time getting the global setting and dead time settings right. I think these injectors should be big enough, right?

 

[gob4sho89]

How do I calibrate the MAS, and is it necessary
?

 

[1992awdlaser]

http://jeffgst.com/gmafcalibration1.html

If raising fuel pressure doesn't lower idc's at all it means the fuel pump isn't keeping up. In which case more fuel pressure will make the problem worse since the pump would have to work harder to mantain the higher pressure. So a way to check if it is the pump would be to lower fuel pressure and see if the idc's go down. Of course this doesn't matter as much now since you bought bigger injectors.

 

[CanadianTSi]

I bet you have a boost leak that is artificially inflating airflow therefore causing the car to think it needs all that extra fuel...

 

[JayRolla]

I bet you have a boost leak that is artificially inflating airflow therefore causing the car to think it needs all that extra fuel...

I agree with CanadianTSi, I had the same issue when I had boost leaks, it would cause the IDC's to go up like crazy.