code59 tuning issues

**Superbee** · 05-10-2014

Hey there, for some reason im having issues trying to tune in 59. its probably something stupid but anyways, im running a 2.0 turbo in a sunbird, 7749 ecm, 3 bar msd map sensor, and code 59.

I upload one of the four base bins. Start it up, and it idles fine....very rich but fine, and on 4 cylinders... They say to adjust the F28 table to get proper idle air fuel... well any adjustment I make it will start misfiring, also, if I leave that alone and try to adjust the idle in the F29X and exact same thing....

I took a quick video to show what I mean...

On stock 58 bin, I can adjust the fuel tables and it changes the a/f ratio just as it should. I don't have a clue what the heck is going on in this 59 setup. I cant do anything.. I already have the timing tables set the same as my stock 58 tune.

https://www.youtube.com/watch?v=QDEyfhT8R2I

**Six_Shooter** · 05-11-2014

That doesn't exactly sound like a "missfire" to me, something is not exactly nice when it does that, almost like retarded timing. The extra fuel is likely masking it.

Have you adjusted the Fuel Injector Offset vs battery voltage table? I found this table made the largest impact on how smooth my idle was.

Also check that your spark reference angle is set to what the actual base timing is. If this is not correct you can have issues as well.

I would assume after previous threads and discussions that you have the Number of Cylinders scaler set correctly? (0x10)

Yours is still a distributor ignition, correct?

**Superbee** · 05-11-2014

Ok somehow in the madness the tune I decided to go with I actually forgot to change the cylinder # :duh:

So now that that's set, everything adjusts just as it should again, idle does have a hunt to it when its pretty close to 14:7.

One question tho, on the 2.0 ohc, when setting the timing belt, the balancer lines up with the 10 degree timing mark... That being said, do I set the SRA to 10 then?? I see stock is 5.98, and the starter bin is 0..... Is all that irrelevant, and I just set it to what I set my timing marks at with the ALDL jumpered?

Thanks for the response.

**Six_Shooter** · 05-11-2014

What? How the hell are you setting base timing?

The timing belt should really have nothing to do with it, and with the #1 piston at TDC your timing mark should be 0 on the timing tab, if not, then something is off.

To set base timing you need to be in EST bypass mode, meaning you unplug the connector (usually under the passenger side carpet, IIRC some Sunbirds it was along side the main harness near where it comes through the firewall) the tan/black wire. Set your Spark Reference Angle to that base timing.

**1project2many** · 05-11-2014

Turbo Sunbird set timing procedure is similar to early CCC carbureted cars: Jumper A->B and set advance to spec under hood (8 degrees IIRC). By entering diagnostic mode idle rpm is raised and spark advance becomes fixed at the value found at 0x0020, Diagnostic Mode Forced Advance. The factory procedure also calls for using the coil wire rather than #1 plug wire because the torque variations of the crank transmitted to the cam through the belt combined with changes in acceleration of the cam as each lobe comes up on and passes valve max lift causes huge variations in where spark actually occurs at low rpm. I believe this is the reason the distributor is set to 8 degrees when the actual reference angle is set at 6 degrees. I also know from experience that disconnecting the bypass wire so the engine idles down and trying to set timing to six degrees doesn't work so well. It's not that challenging to use this method (although there's no factory connector on the bypass wire) but one has to manually increase idle speed in order to get a consistent reading with the timing light. Ultimately, imo, if sticking to distributor then using the OE method works fine.

So make sure that SRA and the value at 0x0020 is the same in both cals and set timing according to factory spec.

**Six_Shooter** · 05-11-2014

Odd. Hopefully that works the same way with $59.

While we're on the subject, this question would be mostly directed at 1project2many, but anyone else that knows chime in.

Today I swapped from high-z injectors to low-z injectors (1227749, with jumpers in place), and noticed that I seem to have lost true DFCO. I get DE enabled show up on the dash in TP RT, but my AFR remains in the mid teens, where as before, with the high-Z injectors I had the AFR going up to 30:1 and sometimes, though not lately) maxing out my display at 99.99:1. Is this a condition of using the low-z injectors, or should I be looking at something else?