Author Topic: Very rich on lift to shift  (Read 5484 times)

Offline smurfinator

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Very rich on lift to shift
« on: April 19, 2017, 12:43:54 am »
Guys I am truly baffled.  Is there some setting I am not seeing here?   The map is getting to be OK under steady state, but when I lift to shift it swings to .7 lambda.  I have leaned part of the fuel map as much as I dare, but this a huge issue, I just failed emissions because of it and I don't see a solution.  Here is my config and a log of low throttle up through the gears up a moderate hill.  I live at 7000 feet MSL so my MAP is really low.  This week I am driving the car down to sea level to live, so that could change my tune again :\.  But I have to get there without burning up twice the fuel or killing the motor or the CATS.

Thanks!

http://www.vems.hu/files/smurfinator/v3.3_u009651-2017.04.19-10.36.42.vemslog

Added more recent log with better tuned config.  Problem remains...

« Last Edit: April 19, 2017, 08:27:25 pm by smurfinator »
Audi ABZ 4.2 V8 in 1993 90 quattro
TTV 60-2 flywheel and cam sync
firmware: 1.2.20

Smurf blue (BMW Laguna Seca), hence the name!

Offline Sprocket

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Re: Very rich on lift to shift
« Reply #1 on: April 19, 2017, 08:28:12 pm »
Bottom two rows (maybe even third row also) of VE table need tuning. Less fuel above 3000rpm and more fuel below 2000rpm.

Acceleration enrichments may need tuning also to stop large lean spikes on throttle application, but only after VE table is sorted. Overrun area of fuel map is more sensitive due to the low MAP meaning small alterations to VE value equal large changes in fuel

Overrun fuel cut is disabled........... Enabling overrun fuel cut will help if that is all you do, but still important to tune well around fuel resume area on VE table.

Offline smurfinator

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Re: Very rich on lift to shift
« Reply #2 on: April 19, 2017, 08:41:48 pm »
Hi, thanks I had fuel cut at 2000/1900 and the engine shuts off at 2000 when trying to pull away from a stop. What's that all about?  What's a good setting for 4.2 v8? 

Thanks!
Ben
Audi ABZ 4.2 V8 in 1993 90 quattro
TTV 60-2 flywheel and cam sync
firmware: 1.2.20

Smurf blue (BMW Laguna Seca), hence the name!

Offline smurfinator

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Re: Very rich on lift to shift
« Reply #3 on: April 19, 2017, 08:55:36 pm »
Hi, thanks I had fuel cut at 2000/1900 and the engine shuts off at 2000 when trying to pull away from a stop. What's that all about?  What's a good setting for 4.2 v8? 

Thanks!
Ben


Oh... I just remembered that I fiddled with my throttle body stop.  1-2% miscalibration in TPS would cause fuel cut when pulling smoothly from a stop I bet :\ ?
Audi ABZ 4.2 V8 in 1993 90 quattro
TTV 60-2 flywheel and cam sync
firmware: 1.2.20

Smurf blue (BMW Laguna Seca), hence the name!

Offline Sprocket

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Re: Very rich on lift to shift
« Reply #4 on: April 19, 2017, 10:47:26 pm »
Also for Barometric compensation, it is too disabled.......... Static compensation will compensate for barometric change using the MAP sensor, at power on of ECU. Dynamic requires an additional dedicated Barometric pressure sensor that compensates for barometric change all the time.

Overrun fuel cut should be configured for something like Fuel cut above 2600 and resume below 2000. May also be beneficial to cut fuel below 10kpa since this is usually an overrun condition anyway, or maybe just use this rather than rpm based. Check your data log as to what settings would be suitable for your configuration.

Lastly, make sure the bottom rows of the VE table are well tuned as it tends to have a dramatic effect when way off. Do remember that when you look in the data log that any WBO2 readings are a delayed result of the fuel and air going in, so you need to look at the fuel aspect a little earlier in the data log than the exhaust aspect.
« Last Edit: April 19, 2017, 11:04:32 pm by Sprocket »