going over 100ve. reduce kinjflow or increase injector volt

[V8hilux]

no joy for me... just went out with a cold start, seeing 11/low 12's afr. I am at my wits end. lol. I don't want this to beat me but looks like I'm losing the battle.

Why does this pos go lean when hot.

I just had the engine running in neutral till it was near boiling, seeing 13's afr.. turned it off for 5 mins, then seeing 15's. I just want to sit in the corner of my shed and cry.

WHY.

vl 400 said that the ecu compensates fueling considering charge temps... fair enough. but where is the graph it looks at to calculate the fueling? that's got to be the one i need to change but i can't see it anywhere... lol. does it exist ? or is it hidden in code somewhere as a constant formula?

I bet you could fix it Jayme but which graph would you fiddle with to do it?

[V8hilux]

I'm going to town tomorrow and buying a fuel pressure gauge to see if it is the cause of my woes... but if fuel pressure looks good hot and cold... Im giving in. lol.

[VL400]

Adjust the charge temp tables... they are not fixed, you can adjust them to suit. The names of the tables to change AFR in relation to temp were posted yesterday.

[V8hilux]

ok, so i am looking at my "charge temp inverse temperature term vs charge temp" table, I see the column on the left with the degrees C. I presume this is the charge air temperature. Then I see the column on the right with degrees K. is the degrees K column the fueling correction for when the engine sees the degrees C column?

I don't understand what the numbers do or mean on either column. Are you saying if i change the numbers on the right side that fueling will change when the engine air temp reaches the degrees C column ? so if i wanted to richen the mixture at say 90C manifold air temp (which i do) would i change the degrees K column higher or lower? sorry guys, so confused.

[VL400]

The "% Coolant contribution for calculating charge temp Vs RPM & MAP" table defines at all the load points in it how much impact the coolant temp has on the charge temp - charge temp is what temp the air is entering the cyl. The ECU measures the manifold air temp and then calculates charge temp using that table - look in your logs and see what the manifold and coolant temps do compared to the charge temp, you will see the correlation between the % coolant contribution and the actual charge temp. You can change this table but it is VERY difficult to setup properly.

The inverse temp term is prob the one thats going to be easier to change for you, if you remember back to high school physics and the ideal gas law there is a temp component - for us this is the charge temp, the ECU does a lookup to get the value and you can change it. Adjusting the numbers on the right will change the fuel at the charge temp on the left.

[V8hilux]

That is what I wanted to know, cheers.

The problem with efi tuning for me is that while you guys were in the library reading and doing physics and the gas laws, electron transportation, etc.. . I was was down the back smoking and chasing the girls with all the other dumb kids instead. lol.

But now I might be able to get somewhere now I know what to change.

Failing that I can see the cold engine afr table. If I can't do any good with what you suggest, I might also try changing my cold engine table maximum temperture table from 44 Degrees C to 110 degrees C and make it work all the time and just change the afr's desired at each engine temperature. might be worth a shot.
Thank you.

[antus]

Interesting enough, I have had the same issue on my g200w 2L Gemini. I thought it was an issue with my 4 cyl tune, but I still havnt quite figured it out. Its not a problem most of the time but on a really hot day (35 degrees plus) with a hot engine, and with the crappy location of my air intake (right behind the radiator - yeah I need to move the battery and sort that out!) intake air temps get real hot, and eventually it leans out a point. This is normally aspirated, with camira injectors. The common factor between our cars seems to be the really high under bonnet temps and intake temps. Hopefully my engine will be running again tonight, and then in the next week or so I'll see if I can reproduce it still and figure anything out, although the weather might not be hot enough yet.

[V8hilux]

No win for me...

The gas laws all appear to be fine so i'll leave them there.. If I idle car and let it get super hot, I can see the gas laws doing their job via the bubble tracing. Constant af reading on the wideband.

I then turn car off for 5 minutes and presto, running lean as shit. The manifold temp does not appear to be causing it, or the coolant temp. as they actually go down with shutdown not up as I was thinking with the heatsoak.

Ok, So what is actually happening in the short shutdown that can make such a big change in my AF ratios... Well lets see:

The injectors stop, so they can heatsoak... maybe they see less volts with the sharp increase in temp as no cool fuel running through em.??
The fuel pressure regulator could get hotter with no fuel running through it and maybe jamming the little valve a little??
any numbers of wires could get hot and carry less volts but that can happen while the engine is running so I doubt that is it.
The fuel rail can heatsoak, maybe there is some liquid expansion laws here that would be too confusing for me anyway...

The battery could heatsoak and deliver less volts but it could do that with the engine running so i doubt it's that.

What else could it be?
I am yet to check the fuel pressure hot and cold havent gone to town to buy a gauge yet.

any more ideas I could look into guys?

[V8hilux]

what about the AE temperature factor vs coolant temp, could that do anything for me? dunno what it does?

[darcy]

When it goes lean, what it injector pulse width doing?

Is it reducing - indicating the ecu is trying to lean it up, or
is it same - indicating a mechanical issue in delivering fuel when hot ?