DFCO qualifiers and the weird AE calc 12P

American Delco GM ECUs and PCMs, ALDL, OBD 1.5.
Post Reply
34blazer
Posts: 107
Joined: Mon Dec 31, 2012 4:54 am
cars: '85 S10 Blazer-GT3582R;7730 swap *in progress*
'86 Fiero SE-7730/S_AUJPV4
'87 Mustang GT-7703?S_AUJPV4
'97 Ram SS/T
Location: LasVegastan

DFCO qualifiers and the weird AE calc 12P

Post by 34blazer »

There's only a few qualifiers in 12P for DFCO. Is that all??? There's no RPM delta qualifier so DFCO is active in between shifts, which also leads to a lean tip in condition. Before I turn it off is there such a qualified that is not defined in the current xdf I have?


I'm also not liking the composite AE calculation, it's very crude at best. Was that derived from the original calibration? I really need a TPS based AE because right now this one size fits all logic needs to be rich in most places so that I don't have a lean tip in issue in between shifts or at initial take off. If I had TPS AE all I need to do is adjust the region between 20-30% delta.


Thanks
Image


Image
User avatar
antus
Site Admin
Posts: 8237
Joined: Sat Feb 28, 2009 8:34 pm
cars: TX Gemini 2L Twincam
TX Gemini SR20 18psi
Datsun 1200 Ute
Subaru Blitzen '06 EZ30 4th gen, 3.0R Spec B
Contact:

Re: DFCO qualifiers and the weird AE calc 12P

Post by antus »

I dont think DFCO should be active between shifts, can you post up a log?

The V8 12P data contains the factory data for an MPI Holden 5.0L V8. The offsets are injector milliseconds (quicker to calculate?) so if your running a different flow rate the values will be out. I guess its done this way because its a 2mhz 8 bit computer and its quick to calculate.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
34blazer
Posts: 107
Joined: Mon Dec 31, 2012 4:54 am
cars: '85 S10 Blazer-GT3582R;7730 swap *in progress*
'86 Fiero SE-7730/S_AUJPV4
'87 Mustang GT-7703?S_AUJPV4
'97 Ram SS/T
Location: LasVegastan

Re: DFCO qualifiers and the weird AE calc 12P

Post by 34blazer »

Sure is. I can watch the IPW drop to zero on a free rev. In other calibrations there was a max RPM delta to prevent DFCO from becoming active if the RPMs decreased to quick.
Image


Image
34blazer
Posts: 107
Joined: Mon Dec 31, 2012 4:54 am
cars: '85 S10 Blazer-GT3582R;7730 swap *in progress*
'86 Fiero SE-7730/S_AUJPV4
'87 Mustang GT-7703?S_AUJPV4
'97 Ram SS/T
Location: LasVegastan

Re: DFCO qualifiers and the weird AE calc 12P

Post by 34blazer »

....or at least a delay for the same reason
Image


Image
User avatar
delcowizzid
Posts: 5493
Joined: Sat Feb 28, 2009 8:38 pm
Location: Wellington NZ
Contact:

Re: DFCO qualifiers and the weird AE calc 12P

Post by delcowizzid »

Dfco should only be active if between 1400 and 1500rpm and 19 and 29kpa and above 30kmh.it could be decel enleanment pulling fuel when you lift not actual fuel cut change the manfuel settings for decel enleanment or set the minimum de bpw to something higher than 0 that's in the bin so it can't fully cut fuel
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
34blazer
Posts: 107
Joined: Mon Dec 31, 2012 4:54 am
cars: '85 S10 Blazer-GT3582R;7730 swap *in progress*
'86 Fiero SE-7730/S_AUJPV4
'87 Mustang GT-7703?S_AUJPV4
'97 Ram SS/T
Location: LasVegastan

Re: DFCO qualifiers and the weird AE calc 12P

Post by 34blazer »

delcowizzid wrote:Dfco should only be active if between 1400 and 1500rpm and 19 and 29kpa and above 30kmh.it could be decel enleanment pulling fuel when you lift not actual fuel cut change the manfuel settings for decel enleanment or set the minimum de bpw to something higher than 0 that's in the bin so it can't fully cut fuel

DW, I'm running a 2.0 Opel turbo engine. It doesn't pull as much vacuum as a 3800 or V8 so those settings have been changed to match the characteristics of that engine. What I'm asking is if there is a delay timer or delta rpm parameter, like what is found in other GM calibrations.
Image


Image
Post Reply