I also posted this question in another Forum and received a response from a guy running a similar < 20V 4AGE+ITBs > set-up in (I think) a KE70
He asked me to email him my ECU & Log Files which he reviewed - he made some interesting observations & suggestions* which I think others may learn from. I trust / hope I'm not breaching his trust or any ethical guidelines by posting his observations here;
* He sent me a couple of ECU Files; 1. with & 2. without tweaked timing < Tuning Mode: 1 = MAP, 2=TPS, MAP X TPS >
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1. Post crank enrichment was really low. You had more long post and almost no short post and your short post was for way too long. Its now 20% (was 5%) for the first 3 seconds which is ideal for a dead cold motor. Then its now 4% for 9 seconds on the long post crank enrichment. it was 10% for 15 seconds. You sort of had it arse about. Once the motor fires 20 or 30 times in the first couple of seconds conditions change and its warm in there, therefore enrichment drops pretty fast.
2. Ignition timing on cranking I changed to 6 degrees, just because 10 seems too advanced unless your motor wont start with 6 degrees, but it should. less is more, my 20v used 4 degrees here.
3. I checked your compensation and enrichment tables and found some odd data. As I keep saying you don't need to make any trim tables to play with your ignition, so that has been wiped, all that will do is override your control of the tune, so ditch it! I've zeroed both air and water temp based ignition trim to avoid losing control of the tune.
4. Don't worry about low/high map enrichment, as you just need to worry about getting things simplified so having multiple trim tables for different engine conditions is counter productive. I wiped the high map values and took away a crossover threshold value so that it will default to the low map enrich table vs water temp only as the manual states.
Despite your suggestion that my suggested values were way different to yours, they weren't, i just smoothed your table out as it was pointlessly stepped. The key values are simply the percentage or enrichment at startup temps and then the fact it should zero by operation temp so your maps are accurate for tuning. Yours did this, but it didn't represent an understanding that changes based on temperature are linear or at worst graph-able curve comparisons, so having odd stepped data there is only going to upset something. As such I just smoothed your waveform.
5. I wiped all air temp vs fuel trim from that table for the same reason, it will take control from you.
6. Wiped transient enrichment by un-selecting the Map prediction box and then by zeroing the gain. Again this will affect the accuracy of your logs while tuning. You need steady state conditions and the transient enrich means you need longer steady states to tune from and hold back the amount of data you can make to tune from per drive. Its easy to put back once you have the tune more sorted.
7. Changed your purge valve settings as it was effectively a vacuum leak that would affect your tune. For the small amount it needs to be vented your control conditions have had it on almost all the time while driving, effectively feeding in un-metered fuel almost all the time through a vacuum leak. I have changed it so it only comes on when the amount of air it can feed is comparably low to the motors actual air requirements so that the extra rich air coming in doesn't have a measurable bearing on your tune.
8. You had way too many ignition load points to the point where you would lose a motor on over-rev. You need load points above where you plan to run the motor because shit happens. If you down shift at high speed from 5th to 4th but miss and get second you will spin the motor to 12500 by accident and its more likely to lunch itself if you have no tuning data that makes sense above your rev limit.
Just because you cannot rev the motor there with the accelerator electronically doesn't mean it cannot spin there by some shifting error. Just food for thought.
Plus tuning all those load points is too time consuming and possibly the reason why your tuner got lazy and used lots of repetitive values. You only need to go to less than 500 rpm steps if you cannot control afrs in between load points, in my experience with 4ages 500rpm steps are fine. Anything beyond that is just useless.
9. I dropped the VE tuning and set your tuning to Map vs TPS so that you can have a smoother drive. I put the right values in to implement the map sensor smoothly, with the scaling values between 0 and 1 for fuel and the all 10s in the ignition map to cancel out the control system that divided the product of the 2 maps by ten. Having all tens in this map will allow the values in the timing map 2 to be used as they are.
I tweaked a few of the non load timing values to where I like them, your idle ignition advance was like 17 degrees which is crazy so Ive played with the zero throttle line and then the first couple of vertical columns of the low load points 500 and 1000rpm.
In general a 4AG timing map looks a bit different to yours. Id describe yours as extremely conservative and speaks to me of a tuner too lazy or incompetent to zero the trims and do it right, so rather than do the small amount of work required to do it properly, he just dropped it on a Dyno and did his best as it was, hence the lack of high load advance. You should at least hit 30 degrees BTDC in my opinion at full power full load where your power peaks.
I can see why he didn't, your trim values could have varied this figure by as much as 10 degrees based on air and water temp, he probably saw how much timing was shifiting and then just played it safe.
Looking at all this you should load the map I send back, then just go get a full load half load and quarter load Dyno tune done and then fill in the blanks by road tuning with your wide-band. I've never found a safe or accurate method to road tune for really high load conditions so just do those on a Dyno and then the rest is easy to do yourself.
I've sent you one map with the timing changed and one with all the changes above and the timing not changed.
What we really have done is everything your tuner should have done before tuning your car.
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OK; back to me. . . . .
The car does in fact drive smoother & throttle-off jerkiness has 99% gone but performance is flat(ter). This is is understandable given it is a remote / speculative tune but it's nothing that can't be improved with some road work as he advised. It also leans out on take off / throttle application which he also advised should be remedied by increasing the transient advance.
Another thing to note is that the "idle-droop" whilst improved was still there. I idled the car for about 25 minutes through 2-3 Fan On / Fan Off cycles and each time the idle seemed to drop another 50-75 rpm to the extent that by the 3rd cycle it was sitting on about 750 rpm and getting a bit uneven.
Aside from the fact I have no experience in anything but 1=Unused, 2=TPS tune, much of this information is beyond my knowledge / comprehension envelope so I'm now going to go away for a bit and try get my head around all this . . .
PS: I respect the guy's suggestions regarding a 1/4, 1/2 & full-load tune but having already spent a < 20V+6 Speed > amount of money on accredited Tuners over the years for very mediocre results I am, out of principle not spending a cent more. With this set up from now on its whatever I can achieve via road-tuning. . . If I'm still not happy out it goes to be replaced by a complete Blacktop / 4AGZE + OEM ECU set-up. . .
e420d Ecu Idle & Throttle-Off issues - 16V 4AGE + ITBs
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Originally Posted by Rex_Kelway
Re: e420d Ecu Idle & Throttle-Off issues - 16V 4AGE + ITBs
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