? for Todd- Split BLMs - ZR-1 Net Registry Forums

XfireZ51 · 04-29-2008

Todd,

Is there a way to bring Left and Right BLMs closer in proximity of each other. Left bank runs a bit on the lean side, right bank on the lower side of 128.

tpepmeie · 04-29-2008

I've had this on my 91 a few years back. Its clearly mechanically-related, and I suspect fuel distribution (ie, injectors or rail pressure differences between banks.) The other factor I think contributes can be an exhaust leak, either at the junction just aft of the collector, or at the manifold.

I never truly solved it, but over time, it improved to only a slight difference (3-5 counts). Many things changed over time, so I can't isolate the root cause.

I recall seeing some threads on Thirdgen about split BLMs on minirams, and the idle air circuit was found to be the cause. Memory is a bit foggy there.

Doesn't really hurt anything. Better to focus efforts improving other areas.
Todd

XfireZ51 · 04-29-2008

Todd,

Thanks. I'm not gonna tear my hair out because of it. More curious than anything else. I know that some of the masks have a way of modifying fueling per bank. Wondered if that was available on the ZR masks. Not sure if its part of the MAF v SD issue.
I've seen the fix on the MR with individual ports for the IAC air in each runner. It mostly occurs at low airflow. PT cruise, BLMs are much closer

04-29-2008	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,677	? for Todd- Split BLMs Todd, Is there a way to bring Left and Right BLMs closer in proximity of each other. Left bank runs a bit on the lean side, right bank on the lower side of 128.

04-29-2008	#2
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 795	Re: ? for Todd- Split BLMs I've had this on my 91 a few years back. Its clearly mechanically-related, and I suspect fuel distribution (ie, injectors or rail pressure differences between banks.) The other factor I think contributes can be an exhaust leak, either at the junction just aft of the collector, or at the manifold. I never truly solved it, but over time, it improved to only a slight difference (3-5 counts). Many things changed over time, so I can't isolate the root cause. I recall seeing some threads on Thirdgen about split BLMs on minirams, and the idle air circuit was found to be the cause. Memory is a bit foggy there. Doesn't really hurt anything. Better to focus efforts improving other areas. Todd

04-29-2008	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,677	Re: ? for Todd- Split BLMs Todd, Thanks. I'm not gonna tear my hair out because of it. More curious than anything else. I know that some of the masks have a way of modifying fueling per bank. Wondered if that was available on the ZR masks. Not sure if its part of the MAF v SD issue. I've seen the fix on the MR with individual ports for the IAC air in each runner. It mostly occurs at low airflow. PT cruise, BLMs are much closer Last edited by XfireZ51; 04-29-2008 at 10:19 PM.