LPG Forum


All times are UTC



Post new topic Reply to topic  [ 9 posts ] 
Author Message
PostPosted: Sun Jan 08, 2017 3:13 pm 
New member

Joined: Sat Dec 10, 2016 10:44 am
Posts: 4
Location: Brighton, UK
I've had my Volvo 850 for just over 16 years now, and it was converted to LPG a few weeks after buying it. Overall the LPG kit has been pretty reliable over the years, and I've put over 250k on the car running on LPG.

This year the car failed it's MOT on the emissions. It was presented running on gas, and was also tried (and failed!) on petrol due to a catalytic converter that's way past it's use by date. With the assistance of a very patient MOT tester, we managed to fiddle with the adjustment on the reducer to get it through on LPG. But it's obvious it's in need of a proper service and tune up.

So with this aim in mind, I'm now looking for the right kit to connect up to an ancient Tartarini TEC 97 ECU. I seem to remember the software being an old DOS program with a serial cable. I've found various versions of TEC97/99 software online, but finding the right cable and a laptop with a working serial port might be a little difficult.

The USB cables are much easier to find, and I wouldn't have to dig through the laptop graveyard in the loft. Does anyone know whether it would be possible to use a USB cable with this ECU and software combination, as that would be a much simpler proposition.

I'm guessing that I'm going to have to use something like DOSbox, and I've found a few pages in Polish and German that seem to suggest that this is possible. After installing DOSbox on a PC and running the TEC 97 software I downloaded, it comes up with a communication error (in Polish), which seems like a good start seeing as I don't have the cable to connect it up.

Has anyone any experience with configuring this to work, and any information on the cables needed to connect it up? I'm handy enough with a soldering iron, so should be able to make up an interface cable if a diagram is available.

If it's not possible to get the ECU talking to a PC, would a viable alternative be to replace the stepper motor between the reducer and the mixer with a manual valve and make the tuning adjustments to the reducer in an open loop configuration? Would the adjustments still be correct once the stepper motor is replaced and system running closed loop?


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 08, 2017 4:26 pm 
Advanced Member

Joined: Wed Apr 09, 2008 9:00 am
Posts: 7863
Images: 0
Location: Peterborough
Last point first, depending on how much random twiddling you did to the vaporiser to get it to pass the MoT. Unless the vaporiser is set correctly, using it in open loop will result in a mixture that is correct at idle or at open throttle but not at both.

Using a USB to serial adapter will work sometimes better than others. Adapters using the FTDI chipset are more reliable. Diagram for a suitable serial interface is here

Image

However, one thing to be aware of is going rich at idle is a sure sign that the vaporiser has reached retirement age and after 16 years, it's about 10 years overdue.....

_________________
'96 Saab 900XS, AEB Leo, sold
'93 Range Rover 4.2 LSE, Lovato LovEco, sold
'98 Ex-Police Range Rover 4.0, Singlepoint AEB Leo, my daily motor
'97 Range Rover 4.0SE, eGas multipoint, a project.....

Proud to be a member of the YCHJCYA2PDTHFH club.


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 08, 2017 5:16 pm 
New member

Joined: Sat Dec 10, 2016 10:44 am
Posts: 4
Location: Brighton, UK
Thanks for the reply, and the pin-out diagrams.

I was planning on installing a full service kit into the vaporiser, but didn't want to take it apart until I'd managed to talk to the ECU, as I'd be a bit stuck re-calibrating it afterwards. So when you say 'retirement age', do you mean completely retired, or is a rebuild OK to prolong it's life. It's a Tartarini G79SE. If it's in need of complete replacement, then I assume that there would be other 'time expired' components and I might be better off with a new more modern front end system.

The adjustment for the MOT was very small, it was just over the CO limit, so we adjusted the bias on the reducer the minimum amount so it just scraped through the test, only needed a few degrees movement on the adjuster. It's driving OK and still returning the normal mileage per tankfull, so I doubt it's that far out.

I have USB to Serial adaptors for electronics/microcontroller projects that output the serial signals at 5v levels, so I should be able to connect them direct to the ECU rather than shift them to the RS232 +/-12v levels, and then have to shift them back to 5v using the MAX232 circuit.

As it's not a hardware serial port, I suspect I will have to use DOSbox, does anyone have experience of this?


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 08, 2017 5:32 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 2943
Location: Yorkshire
There was a similar thread recently.

Agreed with Gilbert's above points.

As memory serves I have been able to connect to Tec97 with a wide range of (Tartarini pinout) USB interfaces using a laptop running XP that didn't have a serial port / win 7 32bit running Dosbox worked with a subset of those cables, win 10 running Dosbox a smaller subset.. seems to get worse as version of Windows becomes more recent. Of course, a laptop running an earlier version of windows, or especially DOS, with a proper serial port and cable should have no trouble at all.

Possible to go through a couple of stepper motors (in the flow adjuster valve) during the life of a reducer.

If it won't pass emissions on petrol either I'd be looking at the Lambda probe. Without checking I dunno if 850's use 0-1v probes, I suspect they do, in which case the LPG system will connect to the factory fitted probe signal. On even early V70s the factory (petrol) probe was wide-band, since single point LPG systems are not compatible with wide-band probes any vehicle with one converted to LPG using a closed loop LPG mixer system will have a 0-1v probe fitted as part of the LPG conversion that is additional to the vehicle's factory fitted probe.

Simon

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 08, 2017 5:36 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 2943
Location: Yorkshire
Our above posts crossed, not that it seems to have mattered :lol:

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 08, 2017 8:07 pm 
New member

Joined: Sat Dec 10, 2016 10:44 am
Posts: 4
Location: Brighton, UK
This particular 850 has the 10v engine and Fenix (Siemens) petrol ECU, and uses the 5-0v Titania lambda sensors. The other 850 models (20v & turbos) use the 0-1v sensors. Most of the non turbo P1 V70s also have the same 10v engine/ECU/sensor combination. The petrol system is in fairly good working order, and I think the lambda sensor is OK but should be able to verity it's output using the TEC97 software.

I'd be interested to know about any possible incompatibilities with this type of sensor and a single point LPG system. I'm sure there were settings for Lambda type in the TEC97 software, so would have assumed it should work. Is it a situation of the settings are there, but it's not possible to get it working optimally? Would installing a 0-1v sensor alongside the OEM one be likely to improve things?

The stepper motor seems to be working OK. It's the earlier metal type and has been squirted with carb cleaner and WD40 every time I service the car. Last time I had the LPG side serviced I was told that if I carry on doing that it will 'go on forever', and the newer plastic bodied ones were rubbish.

I wonder if the cables not working on newer versions of windows has anything to do with the fake FTDI chip issue. The newer FDTI drivers block non-genuine USB-serial chips. The XP machine may have drivers that pre-date the blocking, and the Win10 machine will have the latest drivers that recognise (and block) more of the fake chips.

I'm hoping to get the software running under DOSbox on a Linux based laptop. But it'll probably be a good idea to install windows 2000 or XP on an old laptop just to make sure the cables and software are working first.


Top
 Profile  
Reply with quote  
PostPosted: Mon Jan 09, 2017 10:56 am 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 2943
Location: Yorkshire
Dunno then mate, certainly on most V70's I've seen with none slave type LPG systems there's been an additional probe boss welded in the exhaust. I don't remember if Tec97 is compatible with a 5-0v probe, just ran the software in Dosbox but without an ECU connected you don't get as far as seeing any of the options. You'll know more than me about fake FTDI chips and windows driver issues, though I've never had windows refuse to recognise a USB/serial cable. Agreed the older stepper motor and metering units were more reliable than the newer plastic ones.

Simon

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Fri Feb 24, 2017 4:48 pm 
New member

Joined: Sat Dec 10, 2016 10:44 am
Posts: 4
Location: Brighton, UK
Well, I found out what was causing the original problem that resulted in the MOT emissions failure. Over the past few weeks the engine has got harder to start and run on petrol, eventually misfiring so badly (on petrol) that it wouldn't start or idle. On gas it was running much better but still had a slightly rough idle and feeling like it had a little bit of a misfire. After driving it around solely on gas for a few weeks, I thought I'd better make the effort and figure out what was going on.

A few hours of diagnosis revealed that the injector emulator (AEB Pitagora) had given up. The signals to the petrol injectors were being attenuated by varying degrees when running on petrol, and No.2 petrol injector was still firing when running on gas. Opening up the plastic box, and it was clear that there's been a damp problem in there for quite a while, as the circuit board was badly corroded and some of the component legs had rotted through.

A quick call to Tinley Tech and a replacement arrived next day. The car now runs smoothly again, and a check by my friend at the MOT station shows that the emissions are well within the limits on both petrol and gas.

I still plan to wire up an interface cable, and maybe give the reducer an overhaul once I'm equipped to check the ECU settings, but for the moment it's nice to have found the original problem and have it running properly again.


Top
 Profile  
Reply with quote  
PostPosted: Mon Feb 27, 2017 3:25 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 2943
Location: Yorkshire
Nice one, yeh a broken Pitagora can definitely do that!
Simon

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group