I'm getting ready to install EFI's custom 2-bar OS on my boosted Z06. I have noticed that my LTFTs pretty far off from each other (Bank 1 and 2).

Bank 1 was always slightly higher, but now on Decel, and idle (High Vacuum Moments), Bank1 is about 7% leaner. During Acceleration they are about dead even, so I figured a vacuum leak is probably to blame. I recently insaled 60 lb injectors with the turbo install, and it looked like some where not seated as deeply as other in the stock LS6 manifold. I even heard a vacuum leak coming from one of the injectors O rings in Bank 1. The solution for me was to bend the fuel rail mounting points, and now they all sit in deep, and no more leaks (99% sure of that!) I thought for sure that was why Bank 1 was running leaner.

BUT bank 1 is still running leaner. I even switched the O2s from left to right, same thing. I'm thinking about switching the injectors from one bank to the other, but since the LTFT variance only really occurs at idle, and decel, and steady slow to moderate speed (high vacuum), I still think it is a vacuum leak.

Any ideas, and is 7% even anything to worry about?

Thanks for any info.

Tommy

 

it's normal to have some variance between banks, mine does the same thing but not 7%

 

I switched the left and right injector banks and the problem follows the injectors. I guess I found my problem (now I need to find a solution!) They are 60# injectors that came with my twin turbo kit. Maybe I need to try another set, or another brand. I am not sure what brand these are. They are very skinny, black injectors (if that description helps!)

Tommy

 

The skinny 60# are Mototron injectors. I would take them out and get them flow tested and possibly cleaned (sonic-ly). RCengineering will give you a datasheet to each injector.

Dixit

 

I know that sending the injectors in for a cleaning and flow testing is the best way to go, but I wonder if you would be able to mix the injectors to even out the trims. Maybe switch every other injector from bank to bank to see if your trims level out? Could buy you some time at least until you get some other injectors in there...

 

I was considering that, but my fear is that one injector is just not working right, and one cylinder is not getting enough fuel (BOOM). Also, the car just runs rough at idle and part throttle. Could this just bea function of BIG injectors since the resolution on them (IE. the duty cycle at idle is like 1%) is smaller. They seems to run fine at WOT...

If I wanted to get them flow tested, I just send them out via the mail? What is the turn around time?

Thank for all the info.

Tommy

 

may work to even out the overall affect bank to bank, but you're still gonna have some cylinders runnin lean

 

Are Mototron injectors considered a quality product?

Tommy

 

Mototron injectors are definetely good quality injectors. Turn around time would be best obtained by the place you choose to do the flow testing and cleaning.

Also was your Injector vs MAP table tuned correctly?

Dixit

 

Have you called the shop that sold you the turbo kit? Maybe they'll swap injectors with you if they are new.

 

I already left a message. Their customer service has been amazing, so hopefully this won't be a big deal.

Just as an aside, lets say I get the injectors flow tested, and if a few injectors are clearly not within the same limits, what is the next course of action? Replace just those few injectors? Of can they be tweaked to flow the same?

Thanks again for all the info.

Tommy

PS A twin turboed Z06 is absolutely halarious to drive!