ASYNC, min and max
 

I use TunerPro and the 7747-mine XDF file to edit my bin file. There is settings for ASYNC min. and max.. Now the min ASYNC looks normal to me, set to 350. The max ASYNC is at 47.75 then next to it is 274.50. there is a number in both columbs. Im sure its a mistake on the max ASYNC. May not be either. Im sure there in microseconds. Is any one else using a XDF file for the 7747 that could shed some light on this? Id like to try async in light throttle at around 2500 rpms. if not, ill just try to turn the silly thing off. i change the min async and i think it made a difference. its also weird that the min is set higher than the max. thanks

Most likely the XDF is incorrect. Each of the values (min & max) are double bytes terms in the calibration layout. The max is typically set to 12 msec.

RBob.

Re: ASYNC, min and max
 

Also i want my ECU to stay in ASYNC longer, so im going to change PW - Max SYNC pw to exit ASYNC and raise it. (seems to start in ASYNC when i punch it off the go for tad) Is that how i would go about that?. Can PE engage in ASYNC mode?

Re: ASYNC, min and max
 

I am under injected as it is (stock fuel injectors #50) on a somewhat modified engine. I believe you know the specs, and a single plane edelbrock torquer II intake. I have changed out the swirlies for a set of 416's. Reading up on some of the ASYNC threads, it sounds to me like i need to use async mode, as i found adding alot of AE got my "sluggish" off the go better. Right now I'm not worried about over 4000 rpms, my MPH isn't that good but its where i want it @ 90 mph. I'm trying to get my take off better. I found more AE is needed with smaller injectors is true. And pumping up fuel pressure just makes the fuel hit the tbi walls and dribble down the venturi. Perhaps trying disabling ASYNC altogether woundnt be out of the question as perhaps i could control fuel better in sync?

Re: ASYNC, min and max
 

well, and still, every single ecu, xdf, bin file for these tbis show 274 as max async PW. why is this lower than the minimum? I have searched high and low threw the adresses, simply not there, unless someone has actually figured out the problem. Could the Max value be in Msec instead of Usec? I'd hac an ECU if i knew how. I just dont know how.

Re: ASYNC, min and max
 

Here are the correct '7747 ECU entries for the BPW min/max/bias values:

RBob.

Re: ASYNC, min and max
 

Well, right now im using the 8746, but thats the values i have for the 7747 xdf has the same 274.68 for all the bins (on the max async). So to turn off async, i adjust the Min value all the way up?

Re: ASYNC, min and max
 

The values in the ECU section I posted are different then what you have. To use that section for the '8746 just change the address of each entry.

RBob.

Re: ASYNC, min and max
 

OK. Man that filter for the MAP ($226,$227) for the 8746 is kinda sensative, as for a little goes a long way.:lmao: I believe i eliminated async all together. Accept for the "hole" when i mash the pedal (falls on its face), it now seems like its got some nuts now from 2k-3k rpms. Ive messed with AE some and its better now.

Re: ASYNC, min and max
 

OK i have fixed the Min and Max Async. Now, This isn't what makes the ECU enter Async and exit Async is it? I also see Min BPW and Min BPW Hyst. I want to set the Enter and Exit Async mode. I dont see this in the ASDZ hac, unless Min and Max Async is what its refering to. OK now that i look at what you posted RBob, i tend to believe the 2D6 and 2D8 are the values i want to change. But that hac looks different than mine the way things are labeled. Is there a link to that hac?

Re: ASYNC, min and max
 

OK the Min/Max Async BPW isn't what i need t0 adjust, its the enter/exit, at what addresses are they located at? I went out and got another 7747 like the one i started with, lifes better now. I think maybe my hac is marked wrong, the Min/Max async BPW seems to be working, there are to other params marked Minimum BPW and the other is marked Minimum BPW hyst. Im going to assume those are what im looking for.

Re: ASYNC, min and max
 

I wonder if ZEROing all those out will just turn the thing off, i realy dont care for ASYNC anyway. It has made me nuts.

Re: ASYNC, min and max
 

Setting the values at 2D6 & 2D8 to zero will eliminate async fueling for the regular fuel. AE will still be async, which requires a code change to change to sync only.

Because of the AE fuel you shouldn't muck with the min & max async values too much. Setting those to zero or very high will eliminate your AE fuel.

Back to the async fueling with 2D6 & 2D8. Those values affect when the regular fueling will switch from sync to async, and back to sync. The problem is that it isn't always seamless. Typically the AFR goes lean when the ECM switches to async mode. Which causes surging. With stock injectors at stock fuel pressure the ECM rarely goes into async mode.

Once larger flowing injectors are used, this becomes an issue. In this case it is common to disable the regular fuel async mode.

RBob.

Re: ASYNC, min and max
 

Thanks for getting back to this RBob, I appreciate it. I think i am getting things confused, but maybe not. I surely do not want to turn off AE. The 7747 ecu is confusing though, as far as idle. I thought my 7747 was idling async making it rich. I have always been plagued with rich idle (black sooting the plugs) with the 7747 (no matter where i was setting idle stuff), not with the 8746 though. The 8746 always idled in O/L and i was able to set AFR @ address 233 (idle afr vs Vac (1.8 afr), used instead of afr vs vac) as needed. I think that the 7747 has this but i cannot connect the to. The O/L idle on and off settings doesn't seem to do anything. OR perhaps it is and i cant find the address that controls the AFR O/L idle on the 7747. I think i maybe confusing ASYNC with this idle problem. Im almost positive about switching back to the 8746 soon if i cant get the idle of the 7747 figured out.

Thanks

Re: ASYNC, min and max
 

Does the 7747 have an enter/exit for async fuel?

Re: ASYNC, min and max
 

Both the '7747 & '8746 have the async mode enter/exit PW parameters.

RBob.