Injector Duty Cycle and Pulse Width

[huntsg]

Just hooked up my new powerlogger and was reviewing a file trying to figure out what's going on and how best to tune. Can someone give me the basics on what to look for with injector duty cycle and pulse width? One run had a duty cycle of about 83 and a pulse width of about 18.

 

[QWKRTNU]

Post the log so we can look at it. Do you have a tt chip so you can tune it?

 

[huntsg]

Here they are. Two short runs. First one at a light and eased into it. The second one was from about 35mph.

 

[huntsg]

I have a Gen II and an Extender Extreme Chip so I have quite a bit of tuning available.

 

[Eric Stage I]

Need to know what wideband you have so we can set up our software to read your logs.

Don't tune for duty cycle or pulsewidth, ignore those for now. We care about the A/F and knock. We are only concerned about duty cycle if it's maxed (100%) and you still need more fuel.

Eric

 

[huntsg]

Wideband is an AEM.

 

[TurboBob]

whats the chip number? Which AEM?

Its pretty rich (assuming its the AEM gauge), but thats safe for now.

 

[huntsg]

So, I made an additional pass today. I have the Gen II set at -2.5% fuel across the board and -5% for user tune high load. The target AFR that I've set is 10.8 at WOT. During my passes it never seems to get to that AFR, it is too rich. I'm using the AEM WB. Any suggestions on what to do?

 

[87GN_70GS]

Drop fuel pressure

 

[TurboBob]

dropping fuel pressure goofs up the tune everywhere but WOT.

With a lot of alky flowing, your gas tune is too rich. take another 5% out of the WOT page in the Gen2

Bob

 

[Eric Stage I]

There are a couple different AEM's. They have different outputs. Is yours the AEM guage 30-4100, or the AEM Inline 30-2310?

 

[huntsg]

It's a 30-4100.

 

[Eric Stage I]

Ok, got it now. Looks like you're averaging around 10.3 a/f. Like Bob said, keep going down with high load fuel.

 

[huntsg]

So here is a later run. Since the above run I reduced my timing to 22 degrees and I've taken out another 5% at WOT. With the first 5% at WOT and the 2.5% across the board from the system settings, I have 12.5% coming out at WOT. I didn't get any Kr, but the car felt kind of "choppy" or sputtery once it got into top gear. It appears that the AFR from the WB is better. Do you think the correction factors look good? Thanks.