Pending fault codes P1171 and P1174, tuning advice needed please

[Brian_H]

Not sure its going to help you much, given its an entirely different ecu (KME Nevo), reducer (Romano I think from memory) and injectors (OMVL SL) being used, but might give you some idea (at least its the same vehicle!)

[Bone9]

Yeah not much help tbh, very different software but thank you. I'll have a look at mine tomorrow.

[Bone9]

Step 1 complete, got a bit of gunk out of it...

[Bone9]

Gas pressure at idle is now 1.6 bar, also changed it in the software. Auto calibration next.

[Brian_H]

Might be worth trying to drain it again, looks like a fair bit came out there. Might also be worth a change of filters if you still think its got more to give, though 1.6 bar would seem much closer to what was wanted than you were before.

[Bone9]

No not draining it again, that took ages to get that out. The filters are new. I stopped at 1.6 bar as that was what i was happy with, it still had more adjustment but I'd rather not max it out.

I've had good results that I'm sorting through now but will post shortly.

[Bone9]

After the clean out and pressure change the gas pressure when running on petrol is much lower was 3.5bar now 1.8bar.

[Bone9]

Hopefully you guys can advise on map changes with this info...


























Missed the petrol 60% by mistake but hopefully this will be enough info.

[LPGC]

Change the numbers in the 12.5ms row from 160 and 161 to 135. And change the 134 and 138's in the 15ms row to 130.

[Bone9]

Great thanks. So is everything looking better now?

[LPGC]

Not everything but most things. Have you changed those numbers in the map yet?

[Bone9]

Ah ok what else needs work?

Not yet the laptop has had a hissy fit and is repairing the c drive. As soon as that's done I will.

[Bone9]

Done.

[Bone9]

Just been for a short drive watching the fuel trims. They have gone from -5 to +8 so I reckon I need To change the 135's in line 12.50 to 147. Then line 15 change the 130's to 134.

What do you think?

[LPGC]

A correct map will never have 2 peaks, the necessary peak will occur at moderately low pinj. Your peak at 7ms should probably really be at a bit lower pinj but 7ms is still moderate, there's no way that peak would occur higher than that or there'd be 2 peaks... So you wouldn't have 147 in the 12.5 2000 box if you have 146 in the 10.0 2000 box (because now you've made another peak at 12.5ms).

If the numbers in your map for lower pinjs are correct then I'd doubt you'd need to increase the numbers on the 12.5 and 15/18ms rows. You've said fuel trims have gone from -5 to +8 but haven't said for what engine loads. BTW I guessed the figure I suggested for the 12.5ms row based on your load versus fuel trims table but 'load' isn't particularly helpful... I guessed the load with the negative trims would correspond with the 12.5ms row but you really need to show a table with fuel trims against pinj (not against engine load). Pinj is an exacting figure, engine load is just an abstracted figure that doesn't really point to or mean very much.

[Bone9]

Ah ok I missed the 146 figure. I guessed the 147. Maybe worth trying 145 in the 12.50 row? There will still be only 1 peak then.

The fuel trims changed from 40% and up loads.

Most of the data for the fuel trims and pinj is in the above screenshots and table. I'll have a look tomorrow to see if I can add to the table.

[Bone9]

This is the updated table with what info I had for the unchanged map.

[LPGC]

Lower the figures in the 12ms row from 135 to 130, in the 15ms row from 130 to 120 and in the 18ms row from 126/127 to 115.

[Bone9]

Hi Simon, thanks for the reply but those figures in the table now are from the unadjusted map straight after calibration not from the latest screenshot on here.

What would you prefer? All the same data in the chart but complete and upto date with the current map?

I can get what ever data you need and make a new table if that's the best way for you to advise?

[LPGC]

You could post a pic of your new map after auto-calibration if you like.

But really all you need to do is to adjust figures yourself until fuel trims on LPG are very similar to fuel trims on petrol..
For example: Petrol data shows 13.8/14.01ms with trims of +0.8ltft and -2.3stft (so total trim -1.5%). Then in LPG data you've got 12.46/12.3ms with trims of -13.3 and -11.7 (so total trim of -24%).
If you take 12.3 and add 24% you get 15.25.. So without the -24% trim on LPG you might expect pinj to be 15.25. So if you decrease table figures on the 15ms row by 24% then if the petrol ECU sees the same engine load again and gives pinj of 15ms the LPG calibration should be about right.. But you may still need to decrease figures in the 12.5ms row! Because if figures in the 12.5ms row are too high, and you increase engine load slowly up to what would (with good LPG calibration of the 12.5ms row) see pinj rise up to 15ms instead see pinj rise only up to 12.5ms with negative fuel trims. Also the -24% figure may really need to be less extreme than -24%, I said reduce figures in the 15ms row by 24% for clarity when reading this but in practice you may only need to decrease the 15ms row by (say) 15%.. Try it and see but don't forget to also adjust the 12.5ms row.

One more thing since we're talking auto-calibration... Autocal doesn't change the shape of the map, it adjusts all the numbers in your existing map by the same percentage. If you had reset the ECU (or at least reset the map) you'd have the standard shaped map for autocal to change all the numbers on but if you didn't reset the ECU (or reset the map) then if your map shape was already messed up it would still be messed up after autocal.