Saab lpg issues..

[colin33]

Update: I was advised by AC Stag to download the newer software and I was finally able to connect! Although my ECU was fitted in 2011, I'm still not sure if it is a 'stag premium' or 'isa1' because there is no other information on the label.
So, I've renewed all the gas pipes, replaced the Map sensor, filter, and no sign of leaks now.
I fitted the omvl reg fast injectors.
When first plugged into the laptop I get the message "New version of firmware for gas ecu available. Do you want to update it now?" I selected 'no' but should I allow it to update?
Also, 'autoadaption' option is enabled, should I leave this on, what does it actually do?
The lambda sensors are listed as 'not connected' in the software. I haven't yet traced all the wires back so not sure if they are actually connected or not, should they be?
The car now runs on lpg, but badly. On acceleration there is a misfire which puts the engine management dash light on.
Should I now reset the system and start with an autocalibration?
Really happy that I can now connect at least, but some help with the questions above will be much appreciated

[disco stu]

I guess you don't need the picture of the ECU wiring. Good to hear you got it going

I'm not going to pretend I'm an expert, I'm on here asking my own advice. But I can try and help

Have you set the new injectors in the software? Should be somewhere to choose what you are running

I'm guessing new injectors are of a different size. This will affect the tune also. I would think drilling out to the same as the old ones would be best, but I also think its worse to go too large and then LPG injectors won't be able to accurately meter out the gas. Hopefully someone more experienced than myself can offer advice there. Given the difference, I would also think auto-calibration wouldn't hurt to start things off from fresh, but once again wait and see what the more learned members can offer

[Brian_H]

As long as you are confident your lead is now good, then updating the firmware shouldn't be a problem. Its probabbly better to do that before you start trying to calibrate it etc.

I wouldn't bother with the lambda wires if they aren't already connected, they can cause more trouble than help, and if you have any way to view the lambda output or fuel trims then theres little benefit with having them connected.

Autoadaption I would expect will try to try and fine tune as your driving (either by OBD monitoring or some other method - Simon would probabbly be best person to ask on that and I suspect the answer will be to switch it off).

Given its been used on another car, it wouldn't be the worst of ideas to save your current config and reset it after. Worst case you can refer to the original config just in case then!.

Might be an idea to confirm what size nozzles you have fitted to the omvl injectors and what pressure your using before you try going down the calibration route as well

Don't know Stag, but other systems will usually give a clue what they are connected to once you have the software running, a screenshot of the software might help there to identify it, though if you've connected that solves most of that issue anyway.

[colin33]

I guess you don't need the picture of the ECU wiring. Good to hear you got it going

I'm not going to pretend I'm an expert, I'm on here asking my own advice. But I can try and help

Have you set the new injectors in the software? Should be somewhere to choose what you are running

I'm guessing new injectors are of a different size. This will affect the tune also. I would think drilling out to the same as the old ones would be best, but I also think its worse to go too large and then LPG injectors won't be able to accurately meter out the gas. Hopefully someone more experienced than myself can offer advice there. Given the difference, I would also think auto-calibration wouldn't hurt to start things off from fresh, but once again wait and see what the more learned members can offer

Yes thanks Stu, I don't need that picture now. Injectors are set to correct type in software. Simon suggested not using nozzles on these so that's what I've done.

[colin33]

As long as you are confident your lead is now good, then updating the firmware shouldn't be a problem. Its probabbly better to do that before you start trying to calibrate it etc.

I wouldn't bother with the lambda wires if they aren't already connected, they can cause more trouble than help, and if you have any way to view the lambda output or fuel trims then theres little benefit with having them connected.

Autoadaption I would expect will try to try and fine tune as your driving (either by OBD monitoring or some other method - Simon would probabbly be best person to ask on that and I suspect the answer will be to switch it off).

Given its been used on another car, it wouldn't be the worst of ideas to save your current config and reset it after. Worst case you can refer to the original config just in case then!.

Might be an idea to confirm what size nozzles you have fitted to the omvl injectors and what pressure your using before you try going down the calibration route as well

Don't know Stag, but other systems will usually give a clue what they are connected to once you have the software running, a screenshot of the software might help there to identify it, though if you've connected that solves most of that issue anyway.

I like the sound of 'autoadaption' if it tunes as you drive But like you say, Simon may well advise against it. This is the original system fitted to this car, it hasn't been used on another as far as I know. I'm curious as to why it's still running so bad, given that I've now fixed the obvious problems. Maybe it's never run well since fitting in 2011, who knows. Hopefully I'll get my head around the software eventually, it's so different to the AEB King software that I still haven't mastered after 10 years

[Brian_H]

The downside to autoadaption is if something goes wrong (dead lambda sensor or MAF for example) you can find it tries to fix what isn't broken and gets in a mess as a result. At least thats the impression I got from whats been said.

As you say, it may have not been runnng well to start with, different injectors have different characteristics so it will want calibration looking at.

I've got the same injectors without nozzles on two vehicles, they work quite well like that on the right vehicles (1 is a 2.3 engine, other is a 4.0).