Tuning OBD I 3500 (LX9)

[jmgtp]

I've wrapped up the mechanical and wiring on my LX9 swap (formerly 3.4 dohc).
This is in my Grand Prix with 5 speed.

I am using a bin for a 3500/5spd but it isn't running the best. I am using the 3.4 dohc injectors. From what I can smell the motor is running rich.

Here are a few TunerProRT recordings: tunerprologs.zip
Once you unzip the names of the 3 recordings will correspond to the below,

Cold idle, Open Loop
Motor hunts for idle, smells rich, if you rev it will stall when it comes back down to idle.
It fires right up first try, but if you turn it off or it stalls it will not start without a generous amount of throttle.

Warm idle, Closed Loop
idle is stabilized. I tried to move the car just a foot or so by easing the clutch out and it stalled. The idle torque seems low. It revs smooth and does not stall. It blows some very rich smelling smoke when revving. Fires up instantly if turned off or stalled.

Hot idle, closed loop
coolant temps are up to running speed. It no longer hunts for idle or stalls. It revs nice and smooth but it still seems to blow smoke (rich) when revving

Looking for any input. I have the hardware/software to burn bins but not much knowledge on what to change. I'm looking for tuning advice, what to change, etc. OR if there is someone that would like to long distance tune I can pay. This would consist of me sending datalogs, you making changes to a bin, me burning the bin and datalogging again then sending to you and so on until we get it right.

Thanks,
John

[jmgtp]

Also curious, what is the ideal IAC count on a hot motor?

I noticed once warmed up, in closed loop and maintaing an ~800 rpm idle the IAC counts were held around 10. Seems kind of low. I think 20 is a better number that to give more room for adjustment in either direction. I can see if I can adjust the throttle stop screw to close the TB just a hair more without causing the plate to bind on the bore. By reducing air flow there the ecm should compensate and bring the IAC counts up.

[robertisaar]

generally, 20-30 is what i've seen on LH0s and L82s, but i've now seen a ~40 on a lightly cammed 3400.

i'm refering to IAC minimums, BTW. the IAC count at a hot idle should get filtered into the IAC minimum once a few conditions are met and a timer has elapsed.

[jmgtp]

Thanks for the reply. Sounds like my IAC counts are a bit on the low side - this is a stock cam motor, but I think 20-30 sounds better than the really low range of 10. I'll see about allowing the TB to close more in the bore and see if I can get the counts up that way.

I've searched the site but I can't seem to find an FAQ to obdI tuning. I found the definitions page for the terms but no real "guide." Are you aware of one anywhere that I could read? I want to start with idle, then driveability, and then worry about WOT a long time from now.

Basically, I think it is running rich based on what I see/smell out of the exhaust but I want to know how to interpret what I see in TunerPro into changes I can make to the bin. For example, should I be looking at o2 voltage to determine if it is rich? And if so how do I go about leaning it out? What table to adjust, in what direction etc? If there is an FAQ or a DIY site out there somewhere I'd love to know!

[robertisaar]

oh damn..... that's going to be a long read.

i wrote up something a while ago.... it's a bit outdated though IMO, i learn new things occasionally and i've been at this actively since sometime in 2008.

http://60degreev6.com/forum/content.php/150-Tuning-OBD1-Systems/view/1

most important thing to remember though: give the motor what it likes. forcing your idea of how much fuel it SHOULD want or how much timing it SHOULD need will always end up with a comprimised tune.

what mask is the BIN you're using? if it's A1(or DF) based, i have to suggest taking a look into my nAst1 thread, it's basically turning out to be an enhanced mask with me adding whatever capabilites that we might need to make the A1 mask more suitable for engines of past/present and potentially the future.

[jmgtp]

Whoa, that is quite the read. I just went through it briskly and it is a lot to take in.
I'm going to have to read it again, and probably again after that before I can even start to comprehend things. I have about 14 days to get this car running well enough to pass the emissions sniffer test. I've done some basic stuff with bins in the past for the old motor like changing idle speed, iac counts when the AC kicks on, manipulated the shift light output to control something else. So I'm not starting completely from scratch but 'tuning' is a whole other animal and I can tell you by the sights and smells that this motor is NOT anywhere close to being controlled correctly.

I didn't notice anything about tuning open loop vs closed loop? It runs much better once it is in closed loop. The open loop idle is a bit lopey and hunts around and stalls if revved. Once it hits closed loop it stabilizes and can be revved without stalling as the revs drop.

I think I might go back to using the 3.4 dohc bin. At least with that I know exactly what I'm starting with and I am also using 3.4 dohc injectors so it might make the tuning process a bit easier. The 3500 bin I have I don't know anything about it. I believe they are both DF.

[robertisaar]

14 days is likely not enough to get that done if you don't have extensive knowledge of how it all works... then again, you never know.

my suggestion: start logging....a LOT. post the logs and whatever BIN you're running in a ZIP, have the 60V6 community of OBD1 tuners all try out their skills and with enough revisions in that short amount of time, you SHOULD be able to get a solid tune ready for emissions testing.

i'd be willing to lend a hand just for the hell of it.

i don't see anyone trying to troll you and have the idle speed crank up to 3000 RPM or anything like that.

ALSO: how is the test run? that way we can focus on that the most.

[jmgtp]

Really appreciate the offer! I can have the bin and a fresh datalog posted ~6pm tonight. I'll log it idling from cold start all the way up to full running temp @ 195*F.
I can do a second datalog of just HOT engine idle as well. I am using the LX9 heated o2 sensor so I think it can be tuned to go into closed loop sooner than later, especially since it runs better closed loop.

For the test, the car is run on a drum at I believe 30 mph. The drum provides resistance similar to if not the same as a dyno (in fact the emissions test sheet provides a horsepower figure, last time it was tested 2yrs ago it was making something around 11hp to maintain 30mph). They measure hydrocarbons, Nox and I Think CO. They also run the same test at a stop for idle emissions.

[SappySE107]

Run the DOHC code with the DOHC injectors, and you might be over halfway there.

[jmgtp]

Plan on making that change, makes sense. I'll burn the dohc bin before datalogging.

[robertisaar]

Run the DOHC code with the DOHC injectors, and you might be over halfway there.

any specific reason(s) for this, Ben? it's easy enough to copy/paste anything injector related into A1.

[SappySE107]

Similar TB size and identical injector constants. The 3.4 DOHC is closer to the 3500 in efficiency compared to a 3.1.

[jmgtp]

I switched to the LQ1 bin and it runs much better.
I've attached the bin and the tunerpro run here: LX9 running stock LQ1 bin.zip

Now that I've run it in daylight and I can really see the exhaust while running, there is a big problem. I am certainly burning a lot of oil
Details here: http://60degreev6.com/forum/showthre...511#post438511

[robertisaar]

two things i notice immediately: you ARE running rich before O2 correction and you have a datastream "shudder"(that's the reason for all of those crazy dips and spikes in the values). i have an updated ADX that should correct that.

burning oil is going to be a problem though...

[jmgtp]

Ya the datastream glitches I have no clue on, I'll give your updated file a try tomorrow.

The oil has got to either be stuck rings or a faulty pcv system.