Gen 3 rich idle

[imryan86sb]

My STFT's are cutting as much as -30% and my wideband is still reading between 11-12.5. Runs good. Before I installed the Cat and muffler the AFR reading was almost dead on 14.7. I had about 18-20 inches of 3 inch pipe downstream of my wideband initially; I don't believe I was getting air at the o2 due to the short length. Mute point now, exhaust installed, running rich at idle.

Lq4 with flat top pistons
3" long tube headers and 3" dual exhaust
TS cam 212/218 .550 lift 112 lsa
8.1 delphi fuel inj (42lb)

[5FDP]

Have the tune?

Did you get injector data correct? Never had good luck with marine 8.1 injectors.

[imryan86sb]

Yes , I copied a table from someone off of this forum. Before I changed that table it wouldn't run. It actually runs pretty good, just rich at idle.

I am trying to figure out how to attach my tune. There isn't an attach paper clip???

[5FDP]

Have to click advanced reply to attach files.

[imryan86sb]

Finally

[5FDP]

That tune has the injector data wrong. The injector flow rate stills says 30lb/hr ish injectors and not the 42's you said you installed.

Also you must change ALL the injector data not just the flow rate.

Injector flow rate
Min Injector pulse
Short Pulse adder
Offset vs volts vs vac

All of those must be edited to the correct data.

Fix that stuff and it should idle better. Then you can tune the MAF/VE and work on timing.

[imryan86sb]

After changing all the fuel injector data, I believe the 8.1 injectors are 32 lb not the 42 lb. Anyway here is the tune file and a log file after the change. At the end of the run, it kept bogging out and cut off several times.

[5FDP]

8.1 injectors are 31lb/hr, if that is what they are then using that data would be right. If they were marine 8.1 injectors, they are usually larger.

Pull around 5% from the VE table and close to the same from the MAF table for starters. It's very rich per the fuel trims still with the the injector data changed.

You'll want to put this into open loop and start tuning the MAF or VE first to get fueling squared away.

[Rog]

Finally

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Were you able to sort this out? I also have the 42lb marine injectors in my LQ9 , hot truck cam, TBSS I take and long tubes and we can't get it to run right. Looking for a tune that has the correct injector data for it. Shes tough to find?