AFR goes really rich when boosting

[KDS]

I'm having a fueling problem as soon as the manifold pressure goes into boost and I haven't had any luck getting it to change when I make adjustments in the PE enrichment and / or boost enrichment tables / settings. I'm running a 2 bar SD tune and I have the waste gates set at about 4 psi to start with figuring to work out fueling and timing before adding any more pressure. Prior to the addition of the turbo's I ran the engine with an enhanced SD tune and it ran great with good AFR control. I migrated to the 2 bar SD, and used the values from the NA tune and just modified the boost areas where required. Nothing has changed on the engine except for the replacement of the 1 bar MAP with a 3 bar MAP. I just run this car at the track so I've only had 6 runs with it, but there's something going on with the fueling that I can't seem to correct. The wide band accuracy has been verified and the MAP values are the same as the boost controller values (separate map) so I can't see it being a sensor data error. The data log shows a big drop in AFR with the wide band as soon as I get into boost and it stays that way consistently. The commanded AFR does not have this drop. Because it changes so quickly I can't see any real cause for it in my tune. I found a old post on the site that had a similar issue and it turned out to be a problem with the boost enrichment but i can't see that its a problem in the tune. I've attached the tune and a data log. Any help / comments would be great, I'm running out of idea's.

[5FDP]

Pull a bunch of fuel out of the VE table then.

The tune has a few wrong settings for speed density too. The MAF fail high needs to be at 0hz and the 3 MAF dtc's set to MIL on first error. Then the dynamic airflow settings need to be 8,000/7,900 and not 200/100rpm.


The PE and BE tables are set and forget values. Depending on fuel you are running you need to change them to a specific target. Say you want 12.0 AFR or 11.5 AFR, change it to that and tune the VE table to get you there. If the injector data is correct and your fuel pressure is always steady, you shouldn't have much issue getting it right.

Watch your timing as you add power, your boost area's of the timing tables are still kinda setup like a NA tune.

[KDS]

Thanks for the info. I must have missed the MAF stuff while I was copying from the previous tune. I wasn't aware of the dynamic settings so thanks for that. I was making minor changes to the VE table and not noticing anything so I guess that threw me off. I'll make some larger changes to the VE table and see where it goes. Hopefully I can get some logging done in the next week.