7060 PCM.

TunerCat has thresholds that can be adjusted to go from asynch to synch and vice versa.

Would there be any benefit to changing these thresholds?

 

No one?

 

I've never touched or looked at 7060, but in general, Async has been used by GM to get the PW's bigger in low MAP and idle conditions in order to keep the fuel flow rate accurate (it attempts to anyway). Small PWs on TBI injectors (sub 1.3 ms TOTAL - including vbatt offsets, etc..) tend to get rather lean in a big hurry (although one type of injector that I tested could run just fine at .8 ms total, not sure why). It's difficult to "tune" around a non-linearity, and this brings the flow back to the linear range where x% increase in PW brings the same increase in flow.

 

Thanks.

I just wondered why they would allow this adjustment. Would it be of an advantage to lower the threshold where Async changes to Sync? Currently its set at 6400.

Just wondering if playing with these would allow more fueling leeway at above 4K rpm or so?

 

You can change the crosover point on 747's as well. I just set mine to 0 so that it never goes into Asynch...well accept for AE. All AE is asynch. Car runs much better now. Some cars have problems with the transistion from one mode to the other. Mine did.

 

Can you describe the problems you had during the transition; for instance, what rpm, etc?
Thanks!

 

Red,

TBI injectors!? Which ones?

 

I couldn't really describe it because basically it was erratic. It just seemed like changes I made weren't doing anything, and I would get a stumble and a jump in PW to go along with it. It did this more at low rpm's mostly at idle, or right off idle. Rbob pointed me in the right direction and once I disabled it things started working correctly.

 

Currently, this is what I have:

RPM for Async --> Sync 6375

RPM for Sync --> Async 6350

How low should I go on the Sync --> Async for normal fueling? Is 0 too low?


MAP for Async --> Sync 104.4

MAP for Sync --> Asynce 104.1

Again, is 0 too low for Async --> Sync?


Max Async BPW 11.993 mSec

Min Async BPW 1.404 mSec

Should these 2 be adjusted?


Min Async BPW Hysteresis .504 mSec

Min Sync BPW Hysteresis .305 mSec

Do the Min and Max AFR settings for Open Loop affect commanded WOT AFR?

Thanks!

 

???

 

6000 RPM Sounds like it's set really high to disable it.

 

Its a modified code. VE tables go to 6400.