AE delta manifold fuel

Tuning The Delco In Realtime
Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

AE delta manifold fuel

Postby 9c1vs » Sun Feb 12, 2017 7:31 pm

Just wondering if someone can please explain how the AE delta manifold fuel parameter works exactly? I know how the AE RPM multiplier works, but I am still not 100% on the delta manifold fuel.

Reason being is that I am getting a delay in my wideband dropping to the target AFR when opening the throttle from cruising to around 3/4 or WOT, and when between 1500 to 2000 rpm. The ve calc tells me to up the ve at around 75-90 kpa in this rev range, but when I do that, if the engine holds these points it becomes to rich. I figure I need to keep working on the AE, or maybe it could be something else causing it, possibly my second set of throttles opening up as they are progressive? ( i have a 4 barrel tb on a torque power dual plane hi rise).

Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

Re: AE delta manifold fuel

Postby 9c1vs » Sun Feb 12, 2017 8:45 pm

Actually, I think I just worked it out. Is the high the number, the more fuel is condensed on the manifold walls? I am guessing that there is more fuel condensed on the walls when the throttle is closed or slightly open? And the lower the revs the more fuel would condense too?

User avatar
Posts: 4988
Joined: Sun Mar 01, 2009 2:54 pm
Location: Perth, WA

Re: AE delta manifold fuel

Postby VL400 » Tue Feb 14, 2017 2:07 am

Correct, the ECU estimates how much fuel is condensed in the manifold. Its called manfuel, higher the number the more condensed fuel. This is then used for transient fuel calcs, during AE conditions the condensed fuel is pulled from the walls so its part of the total delivered AE.

In 11/12P changing the item "Transient - AE Gain Vs Delta manifold fuel" will help reduce the lean spot on throttle application more than the normal AE table. Some good gains to be had playing with this, its often overlooked.

Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

Re: AE delta manifold fuel

Postby 9c1vs » Tue Feb 14, 2017 6:05 am

Fantastic thanks! One other question though, are there any general assumptions you can make as to what maifold value the ecu would be referencing at a given time? Say for my engine at around the 1600-2000rpm range, little throttle movements get a rich spike and makes a rough transition. A quick stab to full throttle is fineandporetty well spot on. The problem though is a more gradual opening of the throttle to 3/4 to full will see a delay before the wideband reaches the target afr. On the monitor you can see the ae kick in a little bit then a lean spile and then it usually drops to the target.

User avatar
Posts: 4988
Joined: Sun Mar 01, 2009 2:54 pm
Location: Perth, WA

Re: AE delta manifold fuel

Postby VL400 » Tue Feb 14, 2017 8:11 am

What code are you running? I normally replace an item in the data stream with manifold fuel and watch the AE/DE flags in the monitor (you can add a bitmask item with some ADX changes) when tuning AE.

User avatar
Posts: 9724
Joined: Sat Feb 28, 2009 9:05 pm
Location: Tenambit, NSW

Re: AE delta manifold fuel

Postby Holden202T » Tue Feb 14, 2017 8:24 am

just be careful that the lean spike your seeing is not the map sensor passing through different parts of the VE after the initial AE .....

Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

Re: AE delta manifold fuel

Postby 9c1vs » Tue Feb 14, 2017 9:39 am

I have tried lifting the ve in those areas but it makes the 80kpa area go really high, way higher than 90-100kpa. I did think that might just be what it needs, but if the engine hovers in those areas just underload rather than acceleration it runs really rich like around 10.5-11.5:1 rather than the 13-12.5:1 target.

Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

Re: AE delta manifold fuel

Postby 9c1vs » Tue Feb 14, 2017 9:41 am

VL400 wrote:What code are you running? I normally replace an item in the data stream with manifold fuel and watch the AE/DE flags in the monitor (you can add a bitmask item with some ADX changes) when tuning AE.

I'm using 12p. I'll see if I can change the adx to see it in the monitor like you suggest.

Posts: 79
Joined: Sun Sep 29, 2013 10:33 pm

Re: AE delta manifold fuel

Postby 9c1vs » Tue Feb 14, 2017 10:28 am

VL400 wrote:What code are you running? I normally replace an item in the data stream with manifold fuel and watch the AE/DE flags in the monitor (you can add a bitmask item with some ADX changes) when tuning AE.


I dont seem to have manifold fuel listed in my ADX item browswer in order to add it to my monitor. The closed I have is Decel enleanment applied to BPW.

Is it easy to add it to the list? Is had a look at the add bitmask but I am not really sure what to do!

User avatar
Posts: 4988
Joined: Sun Mar 01, 2009 2:54 pm
Location: Perth, WA

Re: AE delta manifold fuel

Postby VL400 » Wed Feb 15, 2017 11:55 pm

Yeah you wont find it in the browser, it needs to be added to the stream and ADX.

Need to use the flashtool, get bin, bit of hex editing and then write bin. Can post your bin here, or if its 12P V112 hex edit location 0x9BB8 from 0x0084 to 0x0153. This can be done in TunerPro by pressing control+H. Then in the ADX item Coolant Temp Voltage is now manifold fuel, change the calc to X and 0-255 for the data range.

Next

Return to Realtime Delco Tuning

Who is online

Users browsing this forum: No registered users and 1 guest