OBD2 Noob! Do I just copy the L67 injector code?

[SappySE107]

I am tuning a 3.4 DOHC with the L67 injectors. I have set the pressure to 55psi with the key on, engine off. I hope this is the correct way to go about it.

Currently the fuel table is 36.10 rate across the board. The Stock 98 GTP uses a rising fuel rate with kpa, which makes sense but I am not sure if their rate increases more than an NA engine will. Oddly enough the stock 97 3800 code I downloaded was 38 across the board...strange.

I have other questions but I already know I have a LOT to learn with this system. Wish I had the time like when I learned OBD1.

[SappySE107]

I see we are all OBD2 knowledgable around here....

So the answer is yes, you copy that over and set the pressure to 50psi key on, engine off.

VE tune was pretty straight forward, drive with the MAF unplugged and change the MAP tables based on the LTFT/STFT. Once these are close to 0/0, plug the MAF back in. Also, disable PE mode. I lowered the decel values as it was lean on decel, and along with MAF tuning (exported to excel for this since the 97 DOHC setup is pieced together at best and only excel had the MAF in the same values as the programming), I am not nearly done. Decel is smooth, slow speed is smooth, LTFT is with 2% most of the time. Some 3-6% areas but I think I have those down now as well (find out tomorrow). Turned PE back on. Short of a dyno tune, this car is now factory like in how it drives and has plenty of power for how I drive.

3-4 weeks I can start tuning the G6 3900. More tables to play with but I doubt I need to do much to them. Drive by wire would be nice, but I will just make suggestions on the HPT site. Anyone else on there?

[robertisaar]

Fuck that, i'll stick with my "antiquated" OBD1...

[SappySE107]

Thats nice but it doesn't help me in the least.

[mfuller]

I take it the LQ1 code rates the injectors in g/sec? What was the stock value and fuel pressure? L67 injectors are 36#/hr (or thereabouts), but I don't know what pressure that flow rating corresponds to.
I may not be much help because I think my DHP PowrTuner handles injector flow rate differently than HPTuners.

[SappySE107]

The injectors are still #/hr and I never had the bone stock DOHC code. Oldskool had tuned it before me but for headers and it was 36.1# across the board. Now its up to 38.x# at 100 kpa instead. The MAF is g/sec however and I believe it is per cylinder as well. The spark table I still don't fully understand either.

[robertisaar]

what about the spark table? screenshot?

[sprucegagt]

I was away from the boards all weekend. But it looks like you have things figured out. L67 injectors are actually 33 lb/hr at 43.5 PSI. But at 50 PSI they are 36 lb/hr. As for the rising rate deal, unless the MAF, VE, AE and I think some other tables have been layed out with rising rate in mind, I would not use it. So, if stock DOHC code only used a single injector value, then, other than adjusting for flowrate, I would leave it at a single value.

[pocket-rocket]

I didn't touch this one for 2 reasons.

A. I had no clue.

B. It had L67 in the title

I was at Ben's house earlier, and while I still haven't learned to tune yet, HPTuners did seem to do some stuff strange, like the g/cyl vs rpm? heading on the one table (spark?). At either rate, I still fail because I still want to learn OBD1 and haven't done so yet, despite living 45 minutes (or 1 hour+ when I need to get there before a certain time- thanks Sunday drivers...) from Bens house. Everyone needs to stop buying stuff from him for a few weeks so I can learn to tune and we can finish the MGB!




























j/k

[OldSkoolGP]

When I did that in the table, I looked at the L36 code vs. the L67 code, and the L36 code had a flat injector rate. I figured they had a rise in there for additional boost that you would get at low MAP. Initially I had a gradual curve in there, but it ran better to me with a flat set of numbers. And 55 psi at the rail was just to get the most atomization out of the fuel.

[MMGT1]

Flat is the way to go in the 3400's. With those injectors in my ride as well, I am set to 4.30 across the bord. 2.22 was stock. Keep in mind, those are metric #'s

[SappySE107]

Hmm, I may give that a shot once they fix my programmer. I noticed that launching the car right now is worthless, so I certainly screwed that up while fixing idle/normal driving/decel. I was thinking that it is always best to have the fuel setup as close to detailed as possible, but then I remembered that we have 1/100th of the code available and I cannot change everything necessary (most likely). This is a 97 3.4 DOHC and I have no idea what stock code looked like. I doubt Josh changed it to straight up across the board if it wasn't like that to begin with.