SD OL inconsistent fueling issues but why?

[Paz]

I've been battling this for just too long now and it's starting to get the best of me, either time to fix it or get rid of the car/combo if it's never going to be right!

The issue I'm having is i just cannot get it to run consistently in SD OL at all times (can i say due to temps?).

For some time i battled injector tip temp issues until Ghuggins kindly suggested i look into them which did seem to help.

I'll have it running near perfect for out on the highway or cruising (at some temps) then all of a sudden if i get into a bit of traffic etc it will lean out then take some time to get back into line, i just cannot see in my scans anything that could be causing this, surely there must be a way that i can adjust to fix this?

I have had the car looked at (tuned) by a professional tuner (w/ dyno) but issues still remain, since the tune i have only adjusted the VE tables (trying to lean it out a bit at idle) as well as the "offset v inj tip temp" and "Injector Flow Rate Modifier vs. IAT" tables (to the attached tune).

I've tried setting the "Open Loop" and "Open Loop Gains" tables back to stock with no luck.

Engine specs are 6L SBE, reasonable cam, ID1050x injectors, valve springs, single GT42 turbo max 10psi, intercooler, manual, stock fuel pump on 98.

Attached is current tune, 1st scan from cold start (notice fueling is not following commanded), second scan is follow on from first (pretty reasonable), third scan follow on starting to lean out across the board, fourth scan back to normalish again?

Any help would be appreciated.

[Lakegoat]

I have a question. I attached a log from your logs above and at 4000 rpm, you Map sensor reads in the 40kpa's. That seems backward to me. When does your turbo make boost. Are you sure you have a "good" 2.5 bar map sensor?

[SultanHassanMasTuning]

why is your boost enrich map zero'd

also which map sensor is that the scale is a bit strange

[Paz]

I have a question. I attached a log from your logs above and at 4000 rpm, you Map sensor reads in the 40kpa's. That seems backward to me. When does your turbo make boost. Are you sure you have a "good" 2.5 bar map sensor?

Lake my turbo can/will make boost from around 2000rpm, what i was doing here was mucking around populating my VE error table so as i could make some adjustments in the higher rpm/lower map areas (not that i am in there much with normal driving).

Yes starting to question if the map is good (see below).

why is your boost enrich map zero'd

also which map sensor is that the scale is a bit strange

Sultan boost enrich was zero'd by my tuner as we were chasing a hiccup/cough/stutter as the car was coming onto boost (sometimes), issue was intermittent and he (from memory) zero'd out the boost enrichment and adjusted the power enrichment to compensate/do same thing (further reading at the time showed that the stutter is an E38 common thing!)

Map sensor is from the Aust distributor of VCM products (VCM Performance)- https://vcmstore.com.au/products/2-5...ent-map-sensor

VCM Performance 2.5 Bar VE Direct Replacement MAP Sensor

2.5 BAR MAP sensor for use in Late model VE/VF Commodores.

**Can be used in earlier Commodores (pre-2010) with a 2 - 2.5 conversion loom**

HP Tuners/VCM Suite scaling figures below.

Linear: 244.68 kPa

Offset 10.21 kPa

Thanks for the replies gents.

[Paz]

Any other ideas, anyone?

I'm really at a loss here how to get it right?

[07GTS]

dont think it affects anything but u have the flex sensor diagnosis tests enabled even tho there isnt a sensor, where is your iat sensor ? as u are relying solely on that for the calculated manifold temps to correct fueling when SD, should prob try some eoit also if u have a decent cam it may help getting more fuel into chamber as it can affect afr even around cruise rpm quite a bit if its not right, also maby try the cylinder charge temp "bias" set that back to stock and see if it helps if the iat is varying too much causing fueling to change too much it can settle it down combining the iat with ect average so since the ect dosnt move as much it settles any temp swings

[Lakegoat]

I still think you have a problem with the MAP sensor.

[Paz]

dont think it affects anything but u have the flex sensor diagnosis tests enabled even tho there isnt a sensor, where is your iat sensor ? as u are relying solely on that for the calculated manifold temps to correct fueling when SD, should prob try some eoit also if u have a decent cam it may help getting more fuel into chamber as it can affect afr even around cruise rpm quite a bit if its not right, also maby try the cylinder charge temp "bias" set that back to stock and see if it helps if the iat is varying too much causing fueling to change too much it can settle it down combining the iat with ect average so since the ect dosnt move as much it settles any temp swings

It actually does have a flex sensor (series 2 VE) but of course I'm not running it on flex so maybe should disable test just in case?

IAT sensor is mounted down inside inner guard after the intercooler, initially it was mounted right in front of throttle body but was getting terrible heat soak from the fans so I moved it.

Honestly mate I've tried adjusting the EOIT but I'm just not smart (understand) enough and i don't have enough information to be able to do it effectively (i don't think), I don't have the right cam specs (0.06) and i don't have any wide open scans to be able to get inj pulse widths etc which is needed in the calcs, so in affect I'm just guessing for the most part.

From memory i have tried the stock bias temp settings but had no luck (made it worse), shall have a look at my notes.

I still think you have a problem with the MAP sensor.

I'll swap it out (cheap and easy test), I'm guessing genuine GM would be the best option (anyone with a part #)?

[Lakegoat]

GM 2 bar map is 12615136 . Linear 200, offset 8.00
I think there is a 2.5 bar but I don't know the number.

[Paz]

GM 2 bar map is 12615136 . Linear 200, offset 8.00
I think there is a 2.5 bar but I don't know the number.

Thankyou, I'll see what i can come up with over here (prefer not to use same supplier as before if it is an issue), sometimes the US # don't match up with the Aus # for genuine parts.

[Paz]

Just spoke with local Holden (GM) dealer, OEM part number #12592525 references to a 2.5-3 bar map sensor here (US ZL1/ZR1), one ordered and on it's way

Found-
Linear: 312.50
Off-Set: -11.25

Least changing it will rule it out.

[SultanHassanMasTuning]

thats just for the LS9/LSA^

[07GTS]

should keep the flex sensor working as it will make no difference when petrol used but if they are putting in any ethanol least it will correct for it, if ur not sure on eoit just change the boundary to all 520 and zero out the rpm table, and change the ect table where its 110 to 90 and that wont be perfect but it will be alot better should help

[Paz]

thats just for the LS9/LSA^

Yep should be just a simple plug in, swap some numbers then off and running.

should keep the flex sensor working as it will make no difference when petrol used but if they are putting in any ethanol least it will correct for it, if ur not sure on eoit just change the boundary to all 520 and zero out the rpm table, and change the ect table where its 110 to 90 and that wont be perfect but it will be alot better should help

Changes made thank you GTS, shall test and report back hopefully over the weekend.

[lukearmstrong1990]

put stock charge temp bias and filter values back in the tables.

[Paz]

put stock charge temp bias and filter values back in the tables.

I'll give it a try thanks Luke, from memory I have tried it previously but (I think) it actually made it worse.




Attached is a couple of scans with the changes as previously suggested (new 3bar map sensor plus injection timing), inj timing has def made a difference leaning it out enough that i now need to adjust the VE.

Not sure if the new map sensor has made a difference?

Will make some more adjustments, scan and post up asap.


I appreciate the comments and help thanks

[07GTS]

just noticed your boost PE enable is set to 0 kpa and EQ to 1.0 its kinda going to do an odd OL thing there im not sure how it would work or if its interfering with fueling, change the boost PE MAP to 103kpa and make the EQ same as your PE EQ that u use and see if it changes any behaviors because boost PE is enabled by MAP only so it going to think its in boost 100% of the time till u meet PE richer requirements, on mine i set up the PE as it would be in n/a and use the boost PE for fueling, also on your electronic throttle the open area rate limits can be set to all 100% to stop any lag

[Paz]

Morning GTS, I've just gone back through my old tunes (and emails with tuner), the PE/BE settings (as the tune is now) was def when we were chasing a stutter/cough/hesitation when coming onto boost, he did it as an option to try and rule a few things out, did help but never did really stop it totally (later read that it is apparently pretty common for the E38s to have this stutter?).

Couple of screen shots attached, Settings02 is how it is now, Settings01 is how it was originally, I've never adjusted these back to original as i wasn't confident in doing so (without dyno), safe to assume swap them back then?

I will adjust the (33020) Throttle Area Increase Rate Limits thanks.

[07GTS]

u can leave it as is but just change the BE enable map to like 2kpa above your atmospheric pressure if its key on (engine not running) map is 102kpa then make BE enable 104kpa or around that should be fine, and have it set to the 1.250 EQ, and make the PE EQ back to maby 1.180 so its for n/a but still good when ur not quite on boost yet then the richer in BE for when u enter boost, at the moment your straight to the 1.250 which is quite rich if ur not in boost, u could even lower the low to mid TPS enable for PE also as it will prob wind up a bit now and then kick in but if u have it so u can still drive around normal but then get into a bit of throttle maby 35-40% ( i usually look at what TPS makes boost then go a little lower then that ) then it goes into PE can make the transition smoother, where u have 26 in TPS try it on 15 and then ramp to the 8 thats up higher see if thats smoother it should hit PE around 40% throttle and if u have the BE setup if it dosnt enable then the BE will kick it of u do see boost before the PE kicks in for safety also