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Rich bog during acceleration

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Im just reading through this post and have exactly the same issue. I even put the car on a dyno last week and no matter what they did to change the pump setting nothing changed.  I think theres more to it than than just changing the accel and fast accel to fix our issue. DTPS acc gain and DTPS acc max  might play a part in the rich bog. I maybe wrong but is DTPS acc max a percentage of the fast acc 170. So by lowering this value it should pull fuel at wot. DTPS Acc gain is sensitivity to the pedal. I think i might have a play with these setting to see if anything makes a difference.

Mark.

Quote from Shep69 on April 30, 2019, 10:01 pm

Im just reading through this post and have exactly the same issue. I even put the car on a dyno last week and no matter what they did to change the pump setting nothing changed.  I think theres more to it than than just changing the accel and fast accel to fix our issue. DTPS acc gain and DTPS acc max  might play a part in the rich bog. I maybe wrong but is DTPS acc max a percentage of the fast acc 170. So by lowering this value it should pull fuel at wot. DTPS Acc gain is sensitivity to the pedal. I think i might have a play with these setting to see if anything makes a difference.

Mark.

Do you have a log of the dyno run and the dyno graph?

Hi Austin,

Sorry I don't have a log. I know this doesn't help at all. I have a couple of runs of the dyno pull. My car is pretty high geared 3.00  diff with a auto . No stall either so that doesn't help. The guys tried a few different things but  eventually they decided to get the motor to about 2500 rpm and then hit wot. This should have eliminated the no hi stall issue. Still hit 10 or lower then overcompensating and going lean. Cold starts are awesome and cruising around is great but as soon as you step on it  goes way rich. They tried adjusting the accel pump setting with no response.

Cheers Mark

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G'day Shep.

Yes your issues do sound remarkably similar to mine.

I actually tried the approach you suggested yesterday (lowering the DTPS acc max). It didn't seem to have much effect but I'm going to give it a little longer and see if it sorts itself out through self learning.

I've also adjusted the the fuel trim value and put my CID back up to normal.

Austin, I know you said that -35 is the max amount it will trim, but the adjustment on my handheld goes further than that. (I think it was -99 from memory). I've set mine at -50 but not sure if it will make a difference. (doesn't seem to have yet)

I do still wonder though if I'm giving it enough time to adjust.  Having said that though, i'd have thought that adjusting things like the fuel trim and and accell pump settings would have and almost immediate effect. (maybe they are, just not the effect i'm after)

I'm going to hold off on re-loading the V6 file for a bit and continue with the current tune for a while. There are still a few perameters I haven't fully persued and appart from the rich bog it is running pretty good. I've still got some room to move on my accell pump settings (though not much) and I can still pull some more DTPS out and see if that helps.

Ultimatly though if I can not stop it from bogging down under accelleration then the system will have to go.

There is  no point building a high performance engine if you can not use the performance that it can provide. These issues are annoying and are spoiling what should've been a simple (if you believe the spin) and rewarding experience. I did not expect that 3000+ kms and 4 months after getting the car on the road I'd still be trying to tune my engine.

 

 

 

Neil, I want you to try something.  When you are happy with the learn, unplug your O2 sensor.  This will put the sytem in open loop and will go back to the learn tables.  Datalog and report back.

Btw, yes you can adjust the amount of learn.  Not something I normally recommend.

Better yet, just disable AFR Learn and AFR trim.  Leave O2 connected.

Righto.. I'll give that a go over sometime over the weekend

Ok so I think I might be onto something.

Since the software update I now have a lot more adjustable parameters than I had before.

This afternoon whilst fiddling with the system I noticed that under the pro-tuning section there is a selection for Cam fuel adjustment.

This appears to allow for % of fuel to be removed within specific RPM/MAP ranges. So I thought I'd have a play whilst i was driving..

Using CAM3, I started by reducing fuel across the entire fuel table by 10%. This seemed to have a positive effect. From there is started to pull fuel out at specific RPM / MAP ranges.  Overall I seem to be on the right track. From my last drive I've eliminated about 80% of the rich bog issues. Still some work to do but It is definitely much improved.

I hope this is the light at the end of the tunnel because it was getting very frustrating.

Cheers

 

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Deleted userstacknic87

Thanks for the heads up Neil. I'm going to try a few things before I do that. I will get a few logs done and hopefully Austin might be able to help me work out if I have a lean tip in issue or its just going rich straight away.

Glad your getting on top of it.

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Deleted user

This is an old thread but, if on acceleration it spikes lean and it goes rich and keeps going richer [10], why doesn't it reverse and go back to setting or even go lean?

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stacknic87
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