COS5 with 60 lb injectors

[Camaro SS]

With 60 lb injectors with COS5 tuning the TPS VE table it is very rich ~ 12.5 AFR below 5% throttle position. Has anyone else seen this or know what could be done to fix this. The car is running OLSD.

[Tordne]

It's not going to be a COS or TPS VE thing... What pulse widths are you seeing in those areas?

I have SVO42's and i have rich decel and light load as well. I've spent time with the RoadRunner playing with pretty much every table and I can;t get it sorted. there is a magic line, minimum pulse width that you can't go under. If you do they just don't flow anything, on the line they flow to much for the low load areas.

[Camaro SS]

I agree with you that it isn't a COS or TPS VE thing. I tried a few things last night with the Roadrunner also with no luck. Maybe someone can chim in that has figured something out on this.

[Tordne]

Are they disc or pintle style injectors. Apparently the disc injectors can handle lower pulse widths.

So with the RoadRunner you have tried manipulating the Default and Minimum pulse width tables, as well as the Voltage Offset and Small Pulse Adjust?

What pulse widths are you seeing minimum (with DFCO off)?

[Camaro SS]

I haven't played with the pulse widths or voltage offset yet. The injectors are the Mototron 60# injectors. I am not sure if they are disc or pintle style. Here is a thread that I found on ls1tech http://www.ls1tech.com/forums/showth...6227919&conly=

First I am going to hook up a vacuum line from the manifold to the boost reference fuel pressure regulator and see where things are then. It seems like when the fuel pressure regulator sees a vacuum it lowers the fuel pressure just like it will raise the fuel pressure when under boost. If the injectors are still flowing too much under light loads then I am going to play with the pulse width and see and that does.

[joecar]

I haven't played with the pulse widths or voltage offset yet. The injectors are the Mototron 60# injectors. I am not sure if they are disc or pintle style. Here is a thread that I found on ls1tech http://www.ls1tech.com/forums/showth...6227919&conly=

First I am going to hook up a vacuum line from the manifold to the boost reference fuel pressure regulator and see where things are then. It seems like when the fuel pressure regulator sees a vacuum it lowers the fuel pressure just like it will raise the fuel pressure when under boost. If the injectors are still flowing too much under light loads then I am going to play with the pulse width and see and that does.

If you have a MAP-referenced regulator, then your IFR table has to be flat horizontal... you calculate the IFR value from the rated flowrtate/pressure and the rail pressure measured with the reference hose temporarily removed;

See post #8 of this thread: showthread.php?t=3904

yes, vacuum lowers fuel pressure (because vacuum assists injector flow), and boost raises it (because boost impedes injector flow); the aim of MAP-referenced regulator is to keep the pressure difference across an injector constant regardless of MAP (i.e. from the point of view of the injector and it's two ends).

[Camaro SS]

I flat lined the IFR table, hooked up a vacuum line to the MAP-referenced FPR, and even lowered the injector pulse width and it is still rich below 5% throttle position (~12.5 AFR). It seems like nothing I do has any effect on it.

[TAQuickness]

What is your commanded pulse width during this richness?

[Camaro SS]

Damnit, I thought I saved that log. Before I flat lined the IFR table, hooked up the vacuum line, and lowered the pulse width it was 1.846. I lowered the minimum injector pulse width and the default injector pulse width to 1.15 from 2k rpms and below. I didn't change the small pulse adjust. I know this doesn't help much until I get you all more data.

[redhardsupra]

camaross, did you ever figure it out? i have a similar case and i'd like to know if there's a solution