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Re: Conversion of a Volvo V70 (P80) 1999

Posted: Fri Aug 05, 2022 12:19 pm
Goes without saying that poor compression etc could make getting it running properly impossible.

Still don't discount the prospect of it not running in true closed loop mode, even if OBD says it is. It would still read as running in closed loop mode if it were running some sort of emulation and like I said above I've been up against that kind of issue when replacing Koltec gear with aftermarket on Volvo's in the past.

One of the easiest ways for you to tell if it's running true closed loop or emulation is to save a copy of your map (so you can revert back to it by reloading it) and adjusting the mutliplier to see how that effects fuel trims. Bare in mind that there is scope for misinterpretation of readings if it is running emulation because emulation would mean it would really be running open loop and by changing the map you'd be changing actual mixture, if you change mixture (particularly at idle) it can be enough to see the active range of ltft change to a different active range of ltft which can make it seem like it's responding closed loop to your multiplier change when really it's just responding to a different MAF reading because the engine needs a different amount of air to maintain idle speed at different mixtures. Usually if mixture is correct on petrol and you switch to LPG and mixture is correct on LPG the MAF reading will fall very slightly or remain the same. If Maf reading goes down a bit more it can mean it's idling rich on LPG, if it goes up it can mean it's idling lean. Any misfire will immediately make it read lean and increase the Maf reading.

If it didn't have cats You could try the wide band up the tailpipe etc but I wouldn't install it in in place of the existing lambda sensor, like you've said that would be another variable, but also does your Volvo have a standard narrowband probe or is it one of the types that outputs unusual voltage (0.8>1.6v etc) that many Volvo's used? If it's one of the latter type it might be more of a problem to set the Innovate up to give the same range of voltage output.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Fri Aug 05, 2022 8:00 pm
by CNG
Thanks Simon. I've just about grasped your point. I *think* it's not running emulation. The AEB bloke that dabbled with it, made a fair improvement. If his tweaks weren't doing 'something' would I have seen real improvement. This I'm not sure. If you're right, I'm not sure what to do about it. I'm going to have a go a the software again. Methinks it's due a visit to Dai soon.

I'm going to look-up the voltages for my O2/Lambda sensor Denso part No. DOX-1419. Can't find the info easily. If it's the standard cooking voltage, I'll give the Innovate O2 Wideband Gauge a go.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Fri Aug 05, 2022 8:20 pm
Dai would suss whether it was running true or emulated closed loop straight away.

How did you set it up for the dash gauge to show LPG level when running on LPG? That could be telling...

Yes you could see an improvement by him adjusting the calibration if it's running in open loop (or emulated) mode...

I have converted plenty old petrol port injection systems that run open loop fuelling using LPG sequential kit, possible even without using a lambda sensor (but better to use one) because you can see engine manifold pressure at idle and then if you have the experience to know what 'shape' the multiplier map should be it is do-able. Like Maf readings, map readings give info on mixture (as does idle rpm if an idle speed control valve isn't fitted).

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Fri Aug 05, 2022 8:44 pm
by CNG
LPGC wrote: Fri Aug 05, 2022 8:20 pm
How did you set it up for the dash gauge to show LPG level when running on LPG? That could be telling...
Not sure I grasp the root of your question, here goes anyway:

1. The factory-fit tank had a 300bar sensor feeding the factory gauge, aside from moving it about when I re-plumbed, electrically it's as factory. Running the factory gauge. Independent of the Nevo, much as the petrol gauge. Works as it ever did. Could just as well be a petrol-gauge. Accurate too. Only down-side, in factory Bi-Fuels we lose the temp gauge for a gas level gauge. I've nailed in a Scangauge. Gives any info that OBD has to show, including temp. Pic of Scanguage not mine but you get the idea.
Scangauge.png (592.05 KiB) Viewed 156 times

2. The Nevo LED circular switch gauge assembly (DG7?) gets its sensor input via Nevo from an AEB806 CNG gauge. I've never been able to get this particular gauge to dispaly anything wrt fuel-level no matter which type of gauge is entered in the software, messing with software voltages etc or just opting for the obvious - Nevo offer a drop-down for an actual AEB806. Dai tells me fuel-level has no bearing on Nevo operation, provided there's fuel-pressure, KME Nevo will operate. Thus I've not worried about fuel-level indication via Nevo. I've a easier to see and use factory-fit anyway. The AEB806 sits on the reducer. Why have it then? When we're at 200Bar I likes to see physical and constant indication, just because.. if it works on the nevo, that'd be good, but I'd not look at it if it did.
Aiiker 90Ohm Aeb806.png
Aiiker 90Ohm Aeb806.png (1.67 MiB) Viewed 161 times

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Fri Aug 05, 2022 9:28 pm
1. I had forgotten that some factory converted vehicles (some Volvos) have a separate petrol gauge and alternative fuel gauge. The root of my question was regards if you only had the one fuel gauge, and that gauge only switched to alternative fuel when actually running on alternative fuel (otherwise just displayed petrol tank level) then it would be obvious that when you switched to LPG if the single gauge showed alternative fuel tank level instead of petrol level it would mean there were some sort of wiring still connected to the petrol system from the alternative fuel solenoid wiring. Such wiring could also cause the petrol system to switch to open loop or emulated mode. There is still potential for the latter being true (i.e. the petrol ECU, which in case of your Volvo it seems also controls the alternative fuel system, does believe it is running on petrol but still runs open loop or emulated mode due to some wiring).

2. DG7 switches are multi-colour, DG5 are similar but black and white except for the orange reserve fuel level LED and orange 'error' (or run out of fuel) LED. Dai is (as should be expected) correct, the fuel level sensor has no bearing on when the system switches back to petrol... the system switches back to petrol when the actual pressure reading from Nevo's pressure sensor reads gas pressure is below a certain pressure above manifold pressure.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sat Aug 06, 2022 9:22 am
by CNG
Ah, now I see where you're coming from. Running either fuel sees both factory gauges display regardless of which fuel runs. But the rootof your question is still not mis-directed. Now I come to think of it, when i used to run gas (under the Necam system) I'd put a large bet on me seeing the Scangauge read OPEN Loop even after warm-up. CLOSED would only display on petrol. Another reason I think it's not under emulation. And if under Necam, I question if the Denso ECU would fire petrol injectors, it didn't under gas when running Necam. Whereas now, throwing the, still fitted factory 'GAS' switch, cuts the engine.

Then again without your tip, emulation would not have entered my head. And I'm not yet convinced you don't have a point. Will play with it this week. For today, because it's simple, and Dai had strong suspicions i'd need one. Let be, my own experience with my single-point makes my Land-rover near undriveable without 18 degs over petrol for timing advance - I'm going to bang at YET another TAP. I've had appalling luck with these, as I said the firmware power adaptor smoked three.
My TAP collection.png
My TAP collection.png (2.28 MiB) Viewed 141 times

That's, and few would believe it....
2 x Chinese copy AEB510N ( 1 x Alpha + 1 x dodgy Cobra font)
1 x Genuine AEB Cobra
2 x Latest Chinese 'Cobra' - (these look identical to genuine AEB in every way?)
1 x Stag TAP 01
1 x AEB Joker because 6 x AEB510 ( 3 x smoked) is not quite daft enough, and I've a WOLF about somewhere.

I strongly suspect I have 2 x genuine AEB 510 here. They endure extreme scrutiny of the completely identical PCB, tooling-marks on the casing etc etc. Methinks, someone in China has tapped into AEB's production. Yet and all, I'm no fan of AEB, more a case of what I can get.

Wish me luck.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sat Aug 06, 2022 9:36 am
by Brian_H
You'd be able to tell if you have a DG5 or DG7 as if you set the wrong option in the Nevo software, it will protest about it. I know this from having had a DG5 sent in place of a DG7 and finding exactly that to happen.

Theres also a DG4 which is the square type switch with the socket on the back rather than wires.

There are 3 leds on the lefthand side of the DG5, and only 2 on the DG7 as well

The DG7 as said by Simon are mutli colour and can be programmed to show different colours.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sat Aug 06, 2022 10:00 am
by CNG
I'm convinced it's a DG7. My boy spent ages palying with its many colour combinations to get it to do this that and the other under various conditions, and match car interior lighting. Actual fuel-level display with bloody AEB 'change-with-the-wind' format CNG sensor/gauges i'm sure is possible, but for little gain hence too much faff for now.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sat Aug 06, 2022 6:43 pm
by Brian_H
Colour combinations would be DG7 for sure. I've got a DG5 on one of the Nevo installs and that is just white on the level indicator side.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sat Aug 06, 2022 10:07 pm
But, meh, DG5 or DG7 won't really help with your more pressing issues.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Sun Aug 07, 2022 11:44 pm
by CNG
Can't say which colour LED worried me too much. However, ahem...

Halle 'kin lujah! This thing finds its Mojo.

One working AEB510 TAP running Version 08 Volvo specific firmware, and it's a different car. Whilst still driveable this Volvo P80 was gutless and plodding, yet would get along OKish. I wasn't happy, I knew something was wrong, and timing, as suspected forms a large part of it. It's been pretty un-economicla too, this was hitting range. It now has 'as near as I can tell' much the same grunt as running the factory Necam/Koltec install. Suspect range will increase too.

With TAPs simply not available, made worse by me smoking those I could get, along wit the cost of an oscilliscope to establish what was happening, the real solution was £20 in Chinese sourced AEB510N TAP.

The AEB510N has dip-switches. We get advance at 6, 9, 12 & 15 degrees. That's your lot. It's no more optionable than any AEB Joker or AEB Wolf. Which might be a good thing too. Frankly more options on the ignition map wouldn't be good with my level of experience anyway. Despite the firmware being Volvo specific, there's no blurb from AEB for which option to use. I 'dip-switched' it for 12. This despite 15 being pushed as more likely. 12 seems safe. It was late, I'll give it a proper run tomorrow. For the moment, after all the massive hassles with TAPs, I'm happy to make progress.

This leaves questions.

1. I'm going to run with 12 degrees and see how we go. I'm worried with this engine, its 10.5:1 compression ratio is so low (in terms of CNG) that it'll either refuse to pink, or won't be possible to hear. Rather more agricultural, I've yet to get my LR to pink. If it's much the same, and 'dip-switching' to 15 is too much, how will I know if I'm over-cooking this Volvo?

Do anti-knock sensors - assuming we have such things - save us?

2. The Nevo was set-up - such as it is - without the TAP. Is that such a big deal? By this i mean, now I've got the TAP running; until I get it to Dai, it'll be 1000 miles yet before I do - should I sweat?

3. With timing proven to be a large part of what's up -it's not been a pleasant vehicle to own since Nevo - lest we forget I've a Stag TAP 01 sitting here. I bought it because -lead times what they are - I had to consider all options at purchase of the Chinese AEB510. It's offers increasing varaibles. Hence, not even looked at it yet, over my head, I shall leave be. Fearful to rock-the-boat, provided progress keeps at this pace, and in the hands of those more capable than yours truly, is there worthwhile gains in the properly configurable Stag?

4. One fear, I've not been hoodwinked have i? Grunt is back, is it possible the thing is having none of it? Nevo DG7 displays gas runnign in all its LED glory, could it be shoving me back on petrol?

Anyways, now it drives as the car I know.

Re: Conversion of a Volvo V70 (P80) 1999

Posted: Mon Aug 08, 2022 12:44 am
1. It would probably never pink (suffer pre-ignition) on CNG anyway. But still timing can be optimal or far from optimal. If an engine doesn't pink it doesn't mean that timing should be further advanced for best results... In simple terms timing should be advanced to the point at which ignition point in the cylinder sees best compromise between low and building pressure in the cylinder before TDC (BTDC) and high pressure in the cylinder ATDC. Any pressure in the cylinder BTDC makes negative power because the piston is being pushed against the direction of engine travel, any pressure in th ecylinder ATDC makes positive power because the pressure is pushing the piston same way as engine rotation. Pinking is a variable/limitation in ignition timing advance for fuels (petrol) with lower octane and a different burn speed.

2. If it seems to work OK you could do far worse than let Dai finalise the calibration.

The Stag Taps are cheaper and allow setting of different amounts (degrees) of advance at different RPMs, I believe some are also able to read manifold pressure and manifold pressure adds an extra (and intuitive - we would expect it to be there for best results) dimension to the advance curve.