Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Martin_1962 on 04 July 2008, 10:04:36

Title: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 10:04:36
Is there any way I can tell when the car is running open loop - eg full throttle operation and ignoring Lambda signals?

I have an idea but do need to know when running open loop
Title: Re: WOT - open loop running - how can I tell?
Post by: TheBoy on 04 July 2008, 10:47:29
Quote
Is there any way I can tell when the car is running open loop - eg full throttle operation and ignoring Lambda signals?

I have an idea but do need to know when running open loop
Yes, spend £1500 on a 2nd hand Tech2, and do live data reading :P
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 11:01:04
Quote
Quote
Is there any way I can tell when the car is running open loop - eg full throttle operation and ignoring Lambda signals?

I have an idea but do need to know when running open loop
Yes, spend £1500 on a 2nd hand Tech2, and do live data reading :P


Just wondered if there was anything I could monitor - failing that use the kickdown.

No TPS on a DBW is there?
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 11:08:01
What it is is that my car runs a bit lean at full throttle* and a common trick is more injectors. I am considering one extra each side just after the throttle body operated by open loop.

This would give about 30% more gas for this period.

I cannot up the pressure as the injectors do not like high pressures (the issue with Romano plastic jobbies), and replacing both banks with more pressure resisitant injectors may backfire. As the Romanos are very reliable and also pretty quiet, and even user servicable.

I could see Kevin Wood doing this as well.

* this is due to the longer gas injection pulses not being long enough over 6000rpm.

Title: Re: WOT - open loop running - how can I tell?
Post by: TheBoy on 04 July 2008, 11:11:46
Quote
Quote
Quote
Is there any way I can tell when the car is running open loop - eg full throttle operation and ignoring Lambda signals?

I have an idea but do need to know when running open loop
Yes, spend £1500 on a 2nd hand Tech2, and do live data reading :P


Just wondered if there was anything I could monitor - failing that use the kickdown.

No TPS on a DBW is there?
Of course there is a TPS, how the hell else would the ECU know the pedal position ;)
Title: Re: WOT - open loop running - how can I tell?
Post by: TheBoy on 04 July 2008, 11:12:11
Quote
What it is is that my car runs a bit lean at full throttle* and a common trick is more injectors. I am considering one extra each side just after the throttle body operated by open loop.

This would give about 30% more gas for this period.

I cannot up the pressure as the injectors do not like high pressures (the issue with Romano plastic jobbies), and replacing both banks with more pressure resisitant injectors may backfire. As the Romanos are very reliable and also pretty quiet, and even user servicable.

I could see Kevin Wood doing this as well.

* this is due to the longer gas injection pulses not being long enough over 6000rpm.

Larger injectors?
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 11:20:12
Quote
Quote
Quote
Quote
Is there any way I can tell when the car is running open loop - eg full throttle operation and ignoring Lambda signals?

I have an idea but do need to know when running open loop
Yes, spend £1500 on a 2nd hand Tech2, and do live data reading :P


Just wondered if there was anything I could monitor - failing that use the kickdown.

No TPS on a DBW is there?
Of course there is a TPS, how the hell else would the ECU know the pedal position ;)


Might have a look at that
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 11:47:35
Quote
Quote
What it is is that my car runs a bit lean at full throttle* and a common trick is more injectors. I am considering one extra each side just after the throttle body operated by open loop.

This would give about 30% more gas for this period.

I cannot up the pressure as the injectors do not like high pressures (the issue with Romano plastic jobbies), and replacing both banks with more pressure resisitant injectors may backfire. As the Romanos are very reliable and also pretty quiet, and even user servicable.

I could see Kevin Wood doing this as well.

* this is due to the longer gas injection pulses not being long enough over 6000rpm.

Larger injectors?
Title: Re: WOT - open loop running - how can I tell?
Post by: Kevin Wood on 04 July 2008, 12:34:23
Do the Romano injectors have drillable nozzles?

The problem with an extra injector upstream is that your plenum will fill with a lean mixture of gas and air, and the spectre of backfires is awakened. Can you not just revert to petrol at full chat?

An ELM based code reader will give you live data. You can also have a look at the pre-cat lambda sensor output which should toggle while it's in closed loop and go rich (or lean, in your case!) when open-loop.

Personally I'd err on the side of caution and use petrol above 5000 RPM unless you can find a solution to the gas delivery. Lean mixtures under heavy load are not good.

What vapour pressure are you currently running?

I also have a wideband lambda sensor, by the way. That'll tell you exactly what's going on but will require some bodging engineering to connect it to an Omega, I suspect.

Kevin
Title: Re: WOT - open loop running - how can I tell?
Post by: Kevin Wood on 04 July 2008, 12:37:55
Just read again and you are proposing to activate the upstream injector only on a wide open throttle. Now I understand.

You should be able to use one of the signals from either of the throttle pots on the throttle itself or the pedal position sensor.

I would lob a megasquirt on it, then you can have an individual map for each set of injectors.

Kevin
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 15:54:30
Quote
Do the Romano injectors have drillable nozzles?

The problem with an extra injector upstream is that your plenum will fill with a lean mixture of gas and air, and the spectre of backfires is awakened. Can you not just revert to petrol at full chat?

An ELM based code reader will give you live data. You can also have a look at the pre-cat lambda sensor output which should toggle while it's in closed loop and go rich (or lean, in your case!) when open-loop.

Personally I'd err on the side of caution and use petrol above 5000 RPM unless you can find a solution to the gas delivery. Lean mixtures under heavy load are not good.

What vapour pressure are you currently running?

I also have a wideband lambda sensor, by the way. That'll tell you exactly what's going on but will require some bodging engineering to connect it to an Omega, I suspect.

Kevin


Plastic injector onto a pipe then a straw through the plenum into the manifold not far above the petrol injector.

The straws are too long to drill and are Omega specific.

Using petrol at full throttle is too expensive.  When towing you use a lot of full throttle, especially when in the overtaking lane up Birdlip.

Vapur pressure - I need to borrow a lap top and nearly 2 years since I looked but is in the region of 1 to 1.5 bar.

3 bar jams the injectors closed - this is the design flaw.

I suppose it is better than having a block of three go down. All are seperate units
Title: Re: WOT - open loop running - how can I tell?
Post by: Martin_1962 on 04 July 2008, 15:57:24
Quote
Just read again and you are proposing to activate the upstream injector only on a wide open throttle. Now I understand.

You should be able to use one of the signals from either of the throttle pots on the throttle itself or the pedal position sensor.

I would lob a megasquirt on it, then you can have an individual map for each set of injectors.

Kevin

Got the idea off ABS, thought I would just open and leave open for the little period throttle was wide open.

Megasquirt - interesting idea.

I need to find out if it is worth connecting the LPG ECU to a Lambda probe, there is a conenction for it but system N is supposed to not require it.

Anyway what do you think of this idea for open loop enrichment?