Delco Gemini, head scratching ahoy

Converting To Delco ECU From Carby Or Other Injection Systems
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Holden202T
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Re: Delco Gemini, head scratching ahoy

Post by Holden202T »

actually somethings not right, the monitor screen is showing different map reading to the list view :S
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Re: Delco Gemini, head scratching ahoy

Post by Javi »

Injectors are 646cc, Siemens Deka shorts. https://www.efihardware.com/products/64 ... 3.0H-short

MAP is connected to the plenum, and is mounted on the firewall. Wideband is connected. It's a 14Point7 Spartan 2. When it was on the dyno it was showing verry close readings to what the dyno wideband was showing.

My list view and data monitors are showing the same readings as each other - are you sure that's not on your end?
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Re: Delco Gemini, head scratching ahoy

Post by VL400 »

The 3 bar sensor is causing your problems. Its reading over 100kPa even though you are NA. It is common of some 3 bar sensors to read a bit higher, but yours is significantly higher than 100kPa.

Issue is you are starting to use the 100-300kPa boost tables. At 5-6 seconds in have a look at the fuel PW jump up and pretty much flood it due to the VE going from 69% to 96%.
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Re: Delco Gemini, head scratching ahoy

Post by Javi »

VL400 wrote:The 3 bar sensor is causing your problems. Its reading over 100kPa even though you are NA. It is common of some 3 bar sensors to read a bit higher, but yours is significantly higher than 100kPa.

Issue is you are starting to use the 100-300kPa boost tables. At 5-6 seconds in have a look at the fuel PW jump up and pretty much flood it due to the VE going from 69% to 96%.
Sorry, I should have mentioned that this particular motor is turbocharged, that's why it's reading over 100kpa. The VE's do appear to be pretty far out just as it comes on boost though (boost leak in this log. Sorry!)

I think the reason it's so rich around the 3.6k mark is because we were having lean spikes at around that point, and I may have gone a little overkill in trying to stop that... The logs on here look very different to what we were getting on the dyno though, so I'm not sure what's going on there.
Once this 'not revving' issue is sorted out it'll be going back on the dyno, so it /should/ all get evened out then.
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Re: Delco Gemini, head scratching ahoy

Post by slewinson »

Javi wrote:
VL400 wrote:The 3 bar sensor is causing your problems. Its reading over 100kPa even though you are NA. It is common of some 3 bar sensors to read a bit higher, but yours is significantly higher than 100kPa.

Issue is you are starting to use the 100-300kPa boost tables. At 5-6 seconds in have a look at the fuel PW jump up and pretty much flood it due to the VE going from 69% to 96%.
Sorry, I should have mentioned that this particular motor is turbocharged, that's why it's reading over 100kpa. The VE's do appear to be pretty far out just as it comes on boost though (boost leak in this log. Sorry!)

I think the reason it's so rich around the 3.6k mark is because we were having lean spikes at around that point, and I may have gone a little overkill in trying to stop that... The logs on here look very different to what we were getting on the dyno though, so I'm not sure what's going on there.
Once this 'not revving' issue is sorted out it'll be going back on the dyno, so it /should/ all get evened out then.
I would peel that back a chunk - adding nearly 50% more fuel makes no sense to me and might quench the spark, making it feel like you describe.

Simon
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Re: Delco Gemini, head scratching ahoy

Post by Holden202T »

yeah its pretty hard to see whats happening because its revving too quick at the 26 sec mark ... i would certainly suggest smoothing out the VE table in 0-100 and boost tables, the massive spikes you have are not going to be helping things.

its also a good idea to have the 100kpa column copied over into the 100kpa column of the boost ve table just for smoothness of transition.

i dunno what was going on, my laptop was showing the map wrong, but my PC its showing right....

check out here .... if its going that rich on boost i am not surprised that its hitting a wall, your flooding it :P
javi log.jpg
where the VE (green low window trace) is going to 96 percent, its more likely to be needing 60 ve there to get close to the commanded AFR of 12....
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Re: Delco Gemini, head scratching ahoy

Post by VL400 »

Agree with holden202t, its all happening too fast in the log you posted. Try a slow rev (light throttle) in neutral bringing the RPM up to or above where it is breaking down under load, providing the fueling is ok might tell you if its a trigger issue or tune.
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Re: Delco Gemini, head scratching ahoy

Post by Javi »

Okay I tried some of this stuff and got a bit of a mixed bag. When I jab the throttle it'll rev to limiter, but it has the lean spike when switching from the 20-100kpa table to the boost table. This is why I had such high VE's on the boost table, but I'm pretty certain this isn't the right way to go about it. (What is the right way?)

When I slowly feed the throttle in, it goes super rich and kills it around 5.6k, but I'm not really sure why it's doing this; the VE table doesn't seem have a massive spike like that. :?

Here's the modified bin, and two logs - one slow rev and one fast.
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Re: Delco Gemini, head scratching ahoy

Post by VL400 »

I think you will need to use single fire mode at light loads. The injector PW is very very low and will be making idle difficult along with getting a VE table that resembles what the actual engine needs. At the moment you are needing to add VE to get idle PWs high enough to actually fire the injectors, then as RPM rises and injector PW increases to something higher than the opening time are needing to have a lower VE which is not correct.

Set "Run A/F Param - Minimum BPW for sync double fire fuel delivery (Upper Value)" to 2.5ms and ""Run A/F Param - Minimum BPW for sync double fire fuel delivery (Min Value)" to 2ms. This will mean the injectors fire once per cycle when the PW is below 2.5ms, switch to double fire once above that and revert to single fire again when the PW drops to below 2ms.

You also must setup the table "Injector - Injector Bias vs Battery Voltage" to match your injectors for single and double fire switching to work properly.

See how that goes, you will likely find idle will richen right up. Your kinjflow value can probably also be adjusted a bit too, 2.6L and 63lb injectors is about 0.041 compared to your current value of 0.0566. 0.045 is probably closer to what you want allowing for a small fudge factor.
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Re: Delco Gemini, head scratching ahoy

Post by Javi »

VL400 wrote:I think you will need to use single fire mode at light loads. The injector PW is very very low and will be making idle difficult along with getting a VE table that resembles what the actual engine needs. At the moment you are needing to add VE to get idle PWs high enough to actually fire the injectors, then as RPM rises and injector PW increases to something higher than the opening time are needing to have a lower VE which is not correct.

Set "Run A/F Param - Minimum BPW for sync double fire fuel delivery (Upper Value)" to 2.5ms and ""Run A/F Param - Minimum BPW for sync double fire fuel delivery (Min Value)" to 2ms. This will mean the injectors fire once per cycle when the PW is below 2.5ms, switch to double fire once above that and revert to single fire again when the PW drops to below 2ms.

You also must setup the table "Injector - Injector Bias vs Battery Voltage" to match your injectors for single and double fire switching to work properly.

See how that goes, you will likely find idle will richen right up. Your kinjflow value can probably also be adjusted a bit too, 2.6L and 63lb injectors is about 0.041 compared to your current value of 0.0566. 0.045 is probably closer to what you want allowing for a small fudge factor.
Thank you! I had no idea about the single / double fire thing. Will that upset my AFRs under load - particularly on boost? I have to take the car out on Friday night (a friend is coming down from Darwin to drive it) and I don't think I can get it back on the dyno before then. Also, is this why it has the lean spike when it comes on boost? That's one thing that is quite unsettling to me.

Sounds like it's going to need to be re-tuned almost from scratch when I un-fudge the kinjflow value.
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