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I'd like to ask about injector dead time.
I've been doing some tuning of my own config vs a borrowed one from another user and have some weirdness.
Before I start, my setup is:
2931cc, JME cam, 430cc injectors (Green Giants), E85. Reqfuel equation works out to about 11 for gas so I tried 13 to start with E85 enrichment.
Weird thing is that my VE table for idling (12-1300 rpm) which is in the 40s-50s range is pig rich (0.73); with lambda target 1.00 the Autotune wants to reduce the VE into the high teens or low 20s but still not seeing actual lamba above 0.80.
I have played with reqfuel to try a "big hammer" approach and even going as far down as 8 reqfuel the running AFR doesn't budge much.
I have never messed with the injector settings (below) before; these values are WAY off from the published numbers for my injectors.
If I correct these values to match my injector specs can I expect better running?
I have never messed with the injector settings (below) before; these values are WAY off from the published numbers for my injectors.
If I correct these values to match my injector specs can I expect better running?
That is definitely worth a try. Of course you'll have to re-tune your VE table, but that is not too big of a deal.
I have the Siemens-Deka 830cc injectors, and I actually didn't change the dead time specs as the existing settings were close enough, and I found a couple of differing dead time specs online. My AFRs are on target and I even have a decent idle considering they are such huge injectors and are still batch-fired.
I eventually plan to re-wire my injector harness and add a cam sync and go to sequential injection, at which point I'll get into dead times and fine-tuning the idle.
I'd like to ask about injector dead time.
I've been doing some tuning of my own config vs a borrowed one from another user and have some weirdness.
Before I start, my setup is:
2931cc, JME cam, 430cc injectors (Green Giants), E85. Reqfuel equation works out to about 11 for gas so I tried 13 to start with E85 enrichment.
Weird thing is that my VE table for idling (12-1300 rpm) which is in the 40s-50s range is pig rich (0.73); with lambda target 1.00 the Autotune wants to reduce the VE into the high teens or low 20s but still not seeing actual lamba above 0.80.
I have played with reqfuel to try a "big hammer" approach and even going as far down as 8 reqfuel the running AFR doesn't budge much.
I have never messed with the injector settings (below) before; these values are WAY off from the published numbers for my injectors.
If I correct these values to match my injector specs can I expect better running?
Hmmm, I'm not familiar with VEMS or Green Giants but I assume they are a low impedance injector? Either way I've never seen the same dead time across the whole voltage range like that. Is that even physically possible? Maybe that's accounted for somewhere else in VEMS software or there is something I don't know about certain low impedance injectors. If it were me though I would definitely try using the information I had for the particular injectors and see what happens.
Green Giants is nickname for the Bosch green 0280155968 injector I believe originally from a turbo Volvo or something. They are high impedance.
About to try the adjusted deadtime numbers, will advise..
*UPDATE* well it didn't have any negative effect that i can tell so far, if anything it seemingly fired up easier than before with correct latency numbers.
However, further playing with the tune to get the idle AFR right is inconclusive. Something is commanding it way rich regardless of ECT.
My idle VE areas are in the high 40s-low 60s range depending on MAP/RPM and I had to knock them down to 15 (with a 10 reqfuel) to get lambda from 0.7x into low 0.9x.
If somebody has time could you please look over the config attached? I've tried looking at the various things that could enrich the mixture but haven't found anything out of whack to my knowledge.
Basically it is my old settings from when I got VEMS in 2015 or so, but with another RL user's VE/spark tables (starting point) and my Green injectors plugged into it. The car is non-turbo which is why MAP only goes to 100.
Hm, 25.0ms Primepulse before starting, with those big injectors? Moreover your cranking enrichment seems extremely high. 450% @ 30°C or 600% @ 0°C. I can't imagine, if that's really necessary..
Try a maximum of 130% @ 30°C and 150% @ 0°C with a prime pulse of max. 10ms.
*UPDATE* well it didn't have any negative effect that i can tell so far, if anything it seemingly fired up easier than before with correct latency numbers.
However, further playing with the tune to get the idle AFR right is inconclusive. Something is commanding it way rich regardless of ECT.
My idle VE areas are in the high 40s-low 60s range depending on MAP/RPM and I had to knock them down to 15 (with a 10 reqfuel) to get lambda from 0.7x into low 0.9x.
If somebody has time could you please look over the config attached? I've tried looking at the various things that could enrich the mixture but haven't found anything out of whack to my knowledge.
Basically it is my old settings from when I got VEMS in 2015 or so, but with another RL user's VE/spark tables (starting point) and my Green injectors plugged into it. The car is non-turbo which is why MAP only goes to 100.
I can't look through your config right now because my VEMS tuning PC laptop is at my shop (only Macs at home), but go through all of the settings menus and make sure you don't have any trim settings for IAT, EGT, etc. Perhaps the previous VEMS user had an "AnyTrim" compensating table enabled or something like that.
As an example, when I was first setting up my electronic boost control, it worked to a certain point and then something was clearly pulling boost. It turned out that the safety setting for reducing boost versus EGT was set quite low (like 750 degrees C), so I upped it to 900 and that fixed the issue.
Hm, 25.0ms Primepulse before starting, with those big injectors? Moreover your cranking enrichment seems extremely high. 450% @ 30°C or 600% @ 0°C. I can't imagine, if that's really necessary..
Try a maximum of 130% @ 30°C and 150% @ 0°C with a prime pulse of max. 10ms.
Thank you, I will make those adjustments.
I don't believe I've ever messed with those parameters before.
New question...in doing some research on the main VEMS forums I've come across folks discussing the Injector Settings Divider vs Reqfuel number when using batch or sequential injection.
I am using the reqfuel equation as its published and running very rich as mentioned. My injector settings are Divider: 2; Number of injectors: 2. Again this is something I've never messed with previously; it was working fine before changing to the larger engine+injectors+E85. However thinking back I had to play with reqfuel and odd VE numbers back then too...
Since I am running straight batch injection, should I be dividing the calculated reqfuel number by 2? Or should I leave the reqfuel number alone and change Injector settings to 1;4?
Thank you, I will make those adjustments.
I don't believe I've ever messed with those parameters before.
New question...in doing some research on the main VEMS forums I've come across folks discussing the Injector Settings Divider vs Reqfuel number when using batch or sequential injection.
I am using the reqfuel equation as its published and running very rich as mentioned. My injector settings are Divider: 2; Number of injectors: 2. Again this is something I've never messed with previously; it was working fine before changing to the larger engine+injectors+E85. However thinking back I had to play with reqfuel and odd VE numbers back then too...
Since I am running straight batch injection, should I be dividing the calculated reqfuel number by 2? Or should I leave the reqfuel number alone and change Injector settings to 1;4?
I found this different before you posted this. I havent played around with this but I would change req fuel and changing injector settings divider to 1:4. According to help file, as i understand it, you're getting twice the fuel. ( i could be wrong though )
In your config Secondary Trigger Setting / Cam-Sync is enabled (required for full sequential ignition and timed end-angle fuel injection). Do you run a secondary trigger?
Ok, asking for help again.
I did the suggested changes but it doesn't change how rich the car is idling. I am idling at 0.73 or so and its so rich it sounds/feels like its misfiring sometimes.
I changed the injector divider number from 2;2 to 1;4 and it made no difference.
I made sure all spark plug leads (which are brand new along with dizzy cap/rotor/plugs) were firmly seated.
I re-seated all injector connectors.
With engine running I lowered reqfuel in increments from 13 all the way down to 7; RPMs would rise as it leaned out a little bit but going to 7 made it stumble, yet the WB02 barely budged (sensor is fairly new and was free-air calibrated within the last week).
While trying to manipulate things with the engine running to little effect and thinking it was misfiring, I unplugged injectors 1 by 1 to see if one cylinder was dead.
All cylinders are active with a noticeable change in idle with/without each injector plugged in. However, unplugging any given injector would increase the lambda ratio up to 0.84 (since now 1 cylinder was just pumping air). Reconnecting the injector brought lambda back to 0.73 immediately.
Not sure if it applies, but I had to open my throttle butterfly vave slightly, to get more air in when I was running rich .. and I mean really rich, all you could smell at the exhaust end was petrol.
Ok, asking for help again.
I did the suggested changes but it doesn't change how rich the car is idling. I am idling at 0.73 or so and its so rich it sounds/feels like its misfiring sometimes.
I changed the injector divider number from 2;2 to 1;4 and it made no difference.
I made sure all spark plug leads (which are brand new along with dizzy cap/rotor/plugs) were firmly seated.
I re-seated all injector connectors.
With engine running I lowered reqfuel in increments from 13 all the way down to 7; RPMs would rise as it leaned out a little bit but going to 7 made it stumble, yet the WB02 barely budged (sensor is fairly new and was free-air calibrated within the last week).
While trying to manipulate things with the engine running to little effect and thinking it was misfiring, I unplugged injectors 1 by 1 to see if one cylinder was dead.
All cylinders are active with a noticeable change in idle with/without each injector plugged in. However, unplugging any given injector would increase the lambda ratio up to 0.84 (since now 1 cylinder was just pumping air). Reconnecting the injector brought lambda back to 0.73 immediately.
Ok, asking for help again.
I did the suggested changes but it doesn't change how rich the car is idling. I am idling at 0.73 or so and its so rich it sounds/feels like its misfiring sometimes.
I changed the injector divider number from 2;2 to 1;4 and it made no difference.
I made sure all spark plug leads (which are brand new along with dizzy cap/rotor/plugs) were firmly seated.
I re-seated all injector connectors.
With engine running I lowered reqfuel in increments from 13 all the way down to 7; RPMs would rise as it leaned out a little bit but going to 7 made it stumble, yet the WB02 barely budged (sensor is fairly new and was free-air calibrated within the last week).
While trying to manipulate things with the engine running to little effect and thinking it was misfiring, I unplugged injectors 1 by 1 to see if one cylinder was dead.
All cylinders are active with a noticeable change in idle with/without each injector plugged in. However, unplugging any given injector would increase the lambda ratio up to 0.84 (since now 1 cylinder was just pumping air). Reconnecting the injector brought lambda back to 0.73 immediately.
Stumped !
What happens when you decrease the values around idle in your VE-table?
Btw, your MAT/TPS Fuel Enrichment Table is set for (TPS%,MAT°C) FE% (0,20) 105, which is no default value.
I would go back to the default value (0,20) 100.
After posting last night I was thinking the same thing. Going to find a gauge to check pressure; it's entirely possible that the ethanol may have eaten my 15 year old FPR.
Originally Posted by H.F.B.
What happens when you decrease the values around idle in your VE-table?
Btw, your MAT/TPS Fuel Enrichment Table is set for (TPS%,MAT°C) FE% (0,20) 105, which is no default value.
I would go back to the default value (0,20) 100.
I will adjust that table, thanks.
I have to drop the idle-area VE table to 15 to get lambda into the 0.90s. I haven't tried building a whole table around that yet though.
But I really don't want my VE table to be screwy like that, I like the 40-100 range from your table better and thought I could adjust reqfuel to compensate but, maybe not.
05-17-2020, 12:50 PM
