not less than 4.1ms on gas?

[carl0s]

I have 1.9 ohm Hana injectors.

Shouldn't the Stag 300 Premium be able to run the injectors for less than ~4.1ms? It doesn't seem to.

[carl0s]

Hana say there is a 2.36ms opening time, but there is also a 1.2ms closing time.
Does this equate to a minimum tGas time of 3.56ms then, or 2.36ms?

[LPGC]

This might be yet another example of ECU firmware getting a type of injector's minimum pulse duration wrong, I've written about that topic on a few threads recently, the classic firmware min duration error is with OMVL injectors set.

But what did you set injector type as? If the Stag firmware won't allow a shorter duration than 4ms, try setting the injector type to Matrix and see if the problem still exists...

Simon
www.Lpgc.co.ukl

[carl0s]

This might be yet another example of ECU firmware getting a type of injector's minimum pulse duration wrong, I've written about that topic on a few threads recently, the classic firmware min duration error is with OMVL injectors set.

But what did you set injector type as? If the Stag firmware won't allow a shorter duration than 4ms, try setting the injector type to Matrix and see if the problem still exists...

Simon
http://www.Lpgc.co.ukl

Thanks Simon I will try that. I actually set it as "Hana H2000 / H2001 Green".

H2000 is 3ohm, but H2001 is 1.9ohm, yet they only list one option for them both.

I'll try what you said. Thanks. This might help me get the idle tuned better without having to drop the reducer pressure so much.

[carl0s]

OK well, it seems that it does go below 4ms, but only when the car drops to ~2.4ms.

Even if I set the multiplier to 0.7 or something, t-inj-gas never goes below 4.1 when the petrol inj is ~3.8.

I'm not sure if it's just a limitation in the readout on screen, because I think the OBD fuel trims are suggesting that lowering the multiplier is having an effect, even though the t-inj-gas on screen is still hovering around 4.1.

If I tap the throttle to increase RPM a little while in neutral, the t-inj-petrol drops to ~2.4 and the t-inj-gas goes to about 3.4.

Yet for some reason it's impossible to get ~3.4ms t-inj-gas at normal 540rpm idle.

[hardcorepit80]

Shouldn't the Stag 300 Premium be able to run the injectors for less than ~4.1ms? It doesn't seem to.

It should,but why do you think 4.1 is wrong?

2.36ms it's minimum opening time.

H2000 is 3ohm, but H2001 is 1.9ohm, yet they only list one option for them both

The only difference between them is a plug, not resistance.
They used to be 3ohm but now they make only 1.9
Post some screenshots of maps and settings.

What's MAP reading?
Some screenshots would be very helpful.

[carl0s]

Shouldn't the Stag 300 Premium be able to run the injectors for less than ~4.1ms? It doesn't seem to.

It should,but why do you think 4.1 is wrong?

I'm not sure it's wrong, but I thought dropping the multiplier really really low, I should see low numbers, but it would never go below 4.1. It seems unable to do a <1 multiplier ? When the car drops to ~2.4, then indeed the t-inj-gas does go below 4.1, but otherwise, if petrol injectors are 3.4 or above, it is impossible to has gas injectors at less than 4.1ms.

What's MAP reading?
Some screenshots would be very helpful.

There is no MAP (valvetronic), but I will post you some more details once I have fitted my injector nozzles later this week. For now I have dropped reducer pressure to 0.88bar to get things mostly working, but I will fit nozzles.

[LPGC]

This might be yet another example of ECU firmware getting a type of injector's minimum pulse duration wrong, I've written about that topic on a few threads recently, the classic firmware min duration error is with OMVL injectors set.

But what did you set injector type as? If the Stag firmware won't allow a shorter duration than 4ms, try setting the injector type to Matrix and see if the problem still exists...

Simon
http://www.Lpgc.co.ukl

Thanks Simon I will try that. I actually set it as "Hana H2000 / H2001 Green".

H2000 is 3ohm, but H2001 is 1.9ohm, yet they only list one option for them both.

I'll try what you said. Thanks. This might help me get the idle tuned better without having to drop the reducer pressure so much.

No probs Carlos,

Without re-reading this thread (and maybe other threads), what is the car's idle Pinj running on petrol (with fully warmed engine etc)? In fact, what vehicle is this again please?

Hana injectors are fairly linear in my experience but I haven't fitted many of them (because they're bulky, fairly expensive, flow no better and are no more linear than other injectors that are cheaper, cannot be installed in as 'technically correct' positions <because of there bulk> and there isn't enough data on there reliability as yet. But I doubt the performance figures you mentioned are correct, in my experience they perform much better than your info on them suggests, your info would make them average performing injectors even if we went back in time 10 years...

If your engine idles at 3ms on petrol then 4ms Ginj at idle may be too low if you want fueling to be OK at the top end on LPG. In the case of a 3ms idle I would aim for a pressure that gives idle a 3.6ms LPG injector idle, or you may find gas injectors are open full duration with lean mixture at high engine loads.

Simon
www.Lpgc.co.uk

[rossko]

it is impossible to has gas injectors at less than 4.1ms

Is it just a matter of inetrpretation? If it takes 4.1mS for a given size injector to pass a suitable dollop of gas for idling a given engine, it takes 4.1mS regardless of software factors. It's an active closed-loop system, so any attempt to change the factros will result in something else changing to bring the output back to 4.1mS

[carl0s]

it is impossible to has gas injectors at less than 4.1ms

Is it just a matter of inetrpretation? If it takes 4.1mS for a given size injector to pass a suitable dollop of gas for idling a given engine, it takes 4.1mS regardless of software factors. It's an active closed-loop system, so any attempt to change the factros will result in something else changing to bring the output back to 4.1mS

Yes I did think about that but I'm not sure the fuel trims could change that quickly, and besides I was monitoring the trims as this is an OBD-connected Stag, and the trims were at -alot. Also when trying to auto-calibrate, it said nozzles too big!

[hardcorepit80]

If it takes 4.1mS for a given size injector to pass a suitable dollop of gas for idling a given engine, it takes 4.1mS regardless of software factors. It's an active closed-loop system, so any attempt to change the factros will result in something else changing to bring the output back to 4.1mS

rossko is a top man!
I've tried to answer that, but could not put in together

I was monitoring the trims as this is an OBD-connected Stag, and the trims were at -alot. Also when trying to auto-calibrate, it said nozzles too big!

I assume your obd autotune is off, also there's no point doing autocalibration in your case.

[marek]

Dear Carl,

To answer your question, that equates to a "minimum gas time", as you put it, of 1.2mSec.

Consider the following scenarios:-
Any commanded pulse lower than 2.36mSec does not even open the injector - no gas flows.

At any commanded pulse width above 2.36mSec, e.g. a commanded pulse of 2.37 mSec, the injector has opened in the first 2.36mSec and then remains open for a further 0.1mSec. It is then told to close, but it takes 1.2 mSec for it to close and gas is still flowing until it has closed, so the amount delivered is 0.1 + 1.2 mSec = 1.3mSec of gas

Essentially, you can never deliver less than 1.2mSec of gas with this injector.

kind regards
Marek

[carl0s]

Thanks for the information guys. I'm not sure I get it all yet really. Anyway the car runs well with Hana B-type nozzles and 1.1 bar from the dual artic reducers. Injectors on very short tubes right into the bottom of the manifold.

Map looks like this so far:



It needed that little boost post-idle, but as little multiplier as possible at idle.

[hardcorepit80]

it does not look right, don't think multiplier should be around one all the way.... but I've never did valvetronic.
and it's running lean looking at ltft.

[carl0s]

it does not look right, don't think multiplier should be around one all the way.... but I've never did valvetronic.
and it's running lean looking at ltft.

The trims are all over the place and take some time to catch up. I think it will need UEGO AFR to monitor what's going on.

[hardcorepit80]

The trims are all over the place and take some time to catch up.

I think you don't really set it up properly.It takes time, because petrol ECU trying to correct wrong gas mixture.
It will take you miles and miles driving(with someone) to set it up properly....

I think it will need UEGO AFR to monitor what's going on.

You don't need AFR when you're connected to OBD, It will tell you the same thing.

Easy way to do it is to change to LpgTech with MAF control, straight swap with Stag.

[LPGC]

it does not look right, don't think multiplier should be around one all the way.... but I've never did valvetronic.
and it's running lean looking at ltft.

From memory I think my Valvetronic maps usually start with a low multiplier at very low loads and then rise a little and go fairly flat 5ms and above..

Someone has said Valvetronics don't have map, not sure if the intended meaning was that they don't have manifold vacuum or vacuum reference isn't connected. They do have manifold vacuum under certain conditions such as during warm up.

Simon
www.Lpgc.co.uk

[carl0s]

The trims are all over the place and take some time to catch up.

I think you don't really set it up properly.It takes time, because petrol ECU trying to correct wrong gas mixture.
It will take you miles and miles driving(with someone) to set it up properly....

I think it will need UEGO AFR to monitor what's going on.

You don't need AFR when you're connected to OBD, It will tell you the same thing.

Easy way to do it is to change to LpgTech with MAF control, straight swap with Stag.

I don't think LPGTech with MAF is really ready yet. The option is in software, but TechTronic MAF interface is not even in the market yet ("coming soon"), and try to find some advice about it...
http://www.lpgtech.eu/?page_id=5576

I will remove my Stag-OBD interface altogether and see if I can use INPA diagnostics to check live lambda. At the moment it breaks communication after 30 seconds or so.

[hardcorepit80]

don't think LPGTech with MAF is really ready yet. The option is in software, but TechTronic MAF interface is not even in the market yet ("coming soon"), and try to find some advice about it...

They working on MAF adapter, kind of "universal" like Omegas(I think), if you want MAF control you connecting second lambda wire to MAF signal and chose valvetronic option....