Rich deceleration

[mr.prick]

I am using Delphi 42lb fuel injectors @ 60psi
and can not stop a rich condition under low TP% and below 30kPa MAP.
it seems to be mostly related to TP% because i can open the
throttle while @ 30kPa MAP or below and AFR will lean out.
minimum IBPW is 1.7-/+
i am attempting to get the injectors dialed in OLSD.
any injector advice is welcome.
here is what i have so far.

[Tordne]

I remember playing with this a lot a while back and ended up just accepting that the injectors flow too much per min pulse for very low driving conditions. With the RoadRunner PCM I played with offset, min pulse and adjust tables etc. You basically can get to the point where you command such a small pulse width that the injector cannot open, flow fuel and close and you get an AFR like you are in DFCO.

I'd be real interested in other peoples findings though :)

[mr.prick]

You basically can get to the point where you command such a small pulse width that the injector cannot open, flow fuel and close and you get an AFR like you are in DFCO.

i wish i can get that far. :doh2:
min pulse is what it is, it might hit 1.6ms but that`s it, no matter what.
that low IBPW is fine as long as TP% is above 5% or so.

throttle shut = fuel sucking through the injectors.

[joecar]

Can you make B4005 negative...?

[Tordne]

Yup

[mr.prick]

Can you make B4005 negative...?

i`ve done that and with RTACS and,
B4005 does not have an immediate effect on AFR.
i think maybe setting B3701 to the same commanded values in
the 13.5-14.5 volt columns.
above 55 kPa MANVAC is where the richness occurs.

[SSpdDmon]

I zero'd out the short pulse adder. I think that's what B4005 was - the one that looks like a learning curve. Then, I started reducing the times in the injector offset vs battery voltage table. Ideally, those injectors should be good down to 1.4~1.5ms. Below that, they'll probably start missing. The min IPW's refer to what's calculated by the MAF/MAP/IFR tables. The battery voltage offset and B4005 is added on top of that. So, I'd drop the min IPW's down to 0.8 or so. Pull enough out of the battery voltage offset table and the AFR's should lean out. A little richer down low isn't such a bad thing though. Too lean, and you'll get some fun cam surge/bucking.


**JUST REMEMBER** the battery voltage offset table is in MANVAC - not MAP. So, when MAP is low, MANVAC is high. For me, 30kPa MAP = ~70kPa MANVAC because of the altitude I live at.

[mr.prick]

I zero'd out the short pulse adder. I think that's what B4005 was - the one that looks like a learning curve. Then, I started reducing the times in the injector offset vs battery voltage table. Ideally, those injectors should be good down to 1.4~1.5ms. Below that, they'll probably start missing. The min IPW's refer to what's calculated by the MAF/MAP/IFR tables. The battery voltage offset and B4005 is added on top of that. So, I'd drop the min IPW's down to 0.8 or so. Pull enough out of the battery voltage offset table and the AFR's should lean out. A little richer down low isn't such a bad thing though. Too lean, and you'll get some fun cam surge/bucking.


**JUST REMEMBER** the battery voltage offset table is in MANVAC - not MAP. So, when MAP is low, MANVAC is high. For me, 30kPa MAP = ~70kPa MANVAC because of the altitude I live at.

i edited {B3701} across the board, i made 13.5-14.5 volt range match
and @ 60kPa and above i am using RTACS + BEN to get it straight.
seems to be working.:grin:

4567