Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 11 October 2011, 20:22:51

Title: Fuel Trim bank 2
Post by: JamesV6CDX on 11 October 2011, 20:22:51
My lpg setup is working absolutely great on the 3.2. BUT my EML has been on. I thought it was simply the cat efficiency code, and ignored it.

I just read the codes, and had:

cat efficiency bank 1 , to be expected on this car

manufacturer code p1300??

And

fuel trim bank 2.

I have previosly had labda sensor circuit malfunction codes on bank 2 also, despite LPG wiring being fine.

Anyone  had this before? Only seems to log the codes after use on lpg, i think, but cannot be certain of that.

Lpg calibrated and mapped on the road as closely as I can get it.

Car runs as well on gas as petrol, no difference, economy not too bad. O2 sensors do not go lean when booting on either fuel.

Any ideas welcome. My instinct is swap the sensors and then observe if code moves to other  bank ?

Just to add the wiring has  been checked and triple checked...

Cheers,
james
Title: Re: Fuel Trim bank 2
Post by: Kevin Wood on 11 October 2011, 20:25:11
I would watch the fuel trims in live data while driving it on both petrol and LPG first. See what's going on. Could be that the LPG is not as well calibrated as the graph on the stag software leads you to believe.  ;)
Title: Re: Fuel Trim bank 2
Post by: JamesV6CDX on 11 October 2011, 20:45:15
Are you free for a ride in the passenger seat with a laptop anytime soon Mr W? :)
Title: Re: Fuel Trim bank 2
Post by: TheBoy on 11 October 2011, 22:20:29
If the trims drift enough to bring the light on (+-25% on 3.2) on LPG only, then the calibration needs looking at.
Title: Re: Fuel Trim bank 2
Post by: Lazydocker on 11 October 2011, 22:46:16
The new KME reducer is definitely more sensitive to Nozzle size ;)
Title: Re: Fuel Trim bank 2
Post by: Kevin Wood on 11 October 2011, 23:40:06
The new KME reducer is definitely more sensitive to Nozzle size ;)

Having played with Melchett's setup the other day my money is actually on the injectors. They don't appear to open at all below about 3ms pulse width, so if you over-size the nozzles for idle speed, you're stuffed.

Title: Re: Fuel Trim bank 2
Post by: feeutfo on 11 October 2011, 23:49:55
The new KME reducer is definitely more sensitive to Nozzle size ;)
Ime... Was going to say very similar. Too big a nozzle giving too wide a variance between banks for some reason. 1seems to go lean on fuel trim. 2 rich on fuel trim as I recall.

What size are the nozzles? Although If Kev says sumat, I ain't going to argue. 2.3 mill seems a good average.
Title: Re: Fuel Trim bank 2
Post by: feeutfo on 11 October 2011, 23:50:37
Ps I'd guess they are at 2.5 mill currently, perhaps?
Title: Re: Fuel Trim bank 2
Post by: Kevin Wood on 12 October 2011, 10:10:27
Ps I'd guess they are at 2.5 mill currently, perhaps?

Which was certainly too big for Guffer's car (albeit that was a 2.5). Had to back off the pressure quite a bit to get a stable idle.
Title: Re: Fuel Trim bank 2
Post by: JamesV6CDX on 12 October 2011, 12:44:13
Interesting.

My kit was a used one, from Tezray's car. I've a feeling Tez said they were already at 3.0mm, so I just fitted the injectors as they were directly to the 3.2.

I always thought on a 3.2, with the red valtek 3 ohms and a stag kit, 3.0mm was about the right nozzle size?

The software doesn't complain about nozzle size on calibration.

Also - I have to run quite a high pressure, else I get the "injectors fully open" and some unhappyness at high revs....

 :)


Title: Re: Fuel Trim bank 2
Post by: JamesV6CDX on 12 October 2011, 12:45:54
Oh and just to re-iterate, idle is perfect.
Title: Re: Fuel Trim bank 2
Post by: feeutfo on 12 October 2011, 13:05:23
Interesting.

My kit was a used one, from Tezray's car. I've a feeling Tez said they were already at 3.0mm, so I just fitted the injectors as they were directly to the 3.2.

I always thought on a 3.2, with the red valtek 3 ohms and a stag kit, 3.0mm was about the right nozzle size?

The software doesn't complain about nozzle size on calibration.

Also - I have to run quite a high pressure, else I get the "injectors fully open" and some unhappyness at high revs....

 :)



Thought this was a new install...?

 The newer dual feed vaps need a different nozzle size. If a single feed vap as the older set up, will probably need. 3.0 nozzles as you say, I guess!
Title: Re: Fuel Trim bank 2
Post by: JamesV6CDX on 12 October 2011, 13:09:20
It's a Heinz Variety install  ;D

The tank was "new, old stock" from tinleytech, about 4 years old but never used
The filler was new
All pipework and clips are new
The KME Gold is new
The Valtek injectors were NEARLY new (1000 miles use by Tezray, who bought them new)
The loom and ECU are used (Stag 300) made in 2008

HTH  :y
Title: Re: Fuel Trim bank 2
Post by: Kevin Wood on 12 October 2011, 14:08:19
If you have the Valtek injectors then 3mm will be fine. :y

The newer injectors need smaller nozzles.
Title: Re: Fuel Trim bank 2
Post by: JamesV6CDX on 12 October 2011, 14:14:23
Yep, I have valtek 3ohm red ones - like yours I believe Kev.

So doesn't look like a nozzle size issue then?
Title: Re: Fuel Trim bank 2
Post by: Kevin Wood on 12 October 2011, 14:31:46
Yep, I have valtek 3ohm red ones - like yours I believe Kev.

So doesn't look like a nozzle size issue then?

I wouldn't say so. Probably just calibration.

If you want to pop over sometime I'd be happy to have a look. I'd actually be interested in how a 3.2 works with the new vapouriser and the old Valtek injectors.



Title: Re: Fuel Trim bank 2
Post by: TheBoy on 12 October 2011, 18:45:20
The new KME reducer is definitely more sensitive to Nozzle size ;)
Ime... Was going to say very similar. Too big a nozzle giving too wide a variance between banks for some reason. 1seems to go lean on fuel trim. 2 rich on fuel trim as I recall.

What size are the nozzles? Although If Kev says sumat, I ain't going to argue. 2.3 mill seems a good average.
Indeed, TBE needs smaller nozzles...  ...2.5 too big.  Though it says too big during initial calibration, and the occasional fully open when gunning it.