torque management issues?

[johnv]

i am tuning a 99 c5 with a centri blower. using os 02020003/cos3. all was going well and i had the engine up to 6400 rpm at 0.6 bar with a smaller restrictor at 10.9 afr and 13° timing. then i put in the original restrictor and leaned out the mixture a little. now the mixture is around 11.3 until 5200 rpm at 0.6 bar (pulling stronger) but then starts wildly fluctuating between 11.3 and 12.9 until 5900 rpm (0.7 bar). ibpw seems unstable too. nothing weird in ve table as far as i can tell.

could this have to do with traction controll? would i see the reduction in spark when logging sparkadv? there is no change. i dont even know if car has torque reduction by throtle. maybe thats it?

any other ideas as to what might be happening. ignition related maybe?

frames 910 and 3050:

Attachment 18926

(AD2: 0.9= 11.3 afr, 1.2= 12.6 afr)

fuel pressure is as usual btw, falling to 50 psi from 65 psi at idle (AD1).

Fuel pressure should should not drop at all, I suspect you have reached the limit of your fuel system.

[joecar]

thanks, can i make it too? i just dont know where. i would probably know how. once i found some tutorial in v8, lost it and never saw it again.

never mind, this is not the issue, obviously if i tune to 0.9v (and i know 0.95 is 2% less fuel and 0.85 is 2.5% more) or to 11.3 afr or 0.77 lambda doesnt matter. and how accurate the values are in the end only god or the guys with lab equipment know i guess.

if i only knew my torque management is definitely disabled.

I can show you how later.

In the meantime you have the voltage-lambda mapping in your mind already.

[joecar]

+1 I agree with johnv

( if your FPR is un-referenced then rail pressure should stay static +/-1 psi )
( if your FPR is manifold-referenced then rail pressure varies with MAP, which in your log AD1 has no correlation to MAP )

[dian]

i am disapointed that the lingenfelter pump drops off so much. i will probably get the racetronix harness. but fp drops in a consistent maner so it should not be causing what im experiencing.

btw, there probably is no way to logg the pump voltage from the pcm, right? am asking because of b4002. gm.volts is the battery voltage, right? but then this table doesnt make any sence.

[5.7ute]

Plug gaps ?
Also not sure on the 98's but that throttle position pid doesn't look right for ETC. You will need to log the actual throttle blade position to see if an ETC torque limit is in play.

[dian]

good idea on the throttle blade. but what pid do i logg? gm.tp? sae.tp-b/c? gm.etctp1/2?

how can you get some info on the pids? when i rightclick "more info" doesnt work.

[5.7ute]

Like I said I have no experience with the 98 pcm. It should be obvious though if you connect to the vehicle, validate the pids and test. ETCTP I would say is what you need.

[dian]

thanks. it a 99 btw.

[joecar]

Yes, for DBW log the pid GM.ETCTP.

[dian]

i put in the smaller restrictor and made two passes on the resized tune, one to 6200. no problems (except mixture being on the rich side). 155 map, 14.5 ibpw. so at least i know i havent killed the engine yet.

so original restrictor goes back in, but its rainning so further experiments have to wait.

ibpw was at 14.5 (4950) and 15.1 (5300) when engine would bog before. i have been up to 17.5 without restrictor at 5200.

btw, could someone have a look at my dashboad C? how do i format that properly. resize to dashboard does nothing. its too wide.