DWELL DUTY (RAW)

Discussions concerning the M7790 cpu

Moderator: Matt

Post Reply
UNISA JECS
Posts: 365
Joined: Wed Jun 04, 2008 3:48 am
Location: USA Socal
Contact:

DWELL DUTY (RAW)

Post by UNISA JECS » Fri Oct 12, 2018 2:49 am

Hey Matt I found a little discrepancy in the B14 SR20DE "DWELL DUTY" RPM Scale, I included a screen shot comparing to the W10 SR20DET which uses the same distributor as the B14 SR20DE if that means anything

Image
DWELL TIME AND DUTY NISTUNE.JPG
DWELL TIME AND DUTY NISTUNE.JPG (251.15 KiB) Viewed 517 times

Matt
Site Admin
Posts: 8479
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: DWELL DUTY (RAW)

Post by Matt » Fri Oct 12, 2018 10:20 am

Maybe same distributors, but different coils?

I've checked the B14 address file and found there is an override for this parameter over the 32 byte default:
DWELL_DUTY,&HE520,16,1,16,1

E520:0A 0A 18 27 37 46 55 65 74 84 91 99 A3 A9 AE B5
E530:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

You will see the next line in the hex editor is blank, so the table for B14 is only 16 bytes

UNISA JECS
Posts: 365
Joined: Wed Jun 04, 2008 3:48 am
Location: USA Socal
Contact:

Re: DWELL DUTY (RAW)

Post by UNISA JECS » Fri Oct 12, 2018 10:39 am

Matt wrote:Maybe same distributors, but different coils?

I've checked the B14 address file and found there is an override for this parameter over the 32 byte default:
DWELL_DUTY,&HE520,16,1,16,1

E520:0A 0A 18 27 37 46 55 65 74 84 91 99 A3 A9 AE B5
E530:00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

You will see the next line in the hex editor is blank, so the table for B14 is only 16 bytes
I'm not exactly sure on that because both have internal coils in the distributor, pretty much same as

USDM B14 95- 98 OBDII
USDM P10 G20 OBDII
USDM P11 G20 1999 OBDII

My real concern was the bottom RPM axis cutting off early on the B14 vs the W10, thought maybe something was up there as the Values are all exactly the same accept for the 1st value which was 10 for B14 and 0 for the W10

Now I know the early DET's of the AWD variety and the early OBDI FWD DE's used external coils so im sure the Values would be totally different, and then the RWD is COP so those would be totally different.

Matt
Site Admin
Posts: 8479
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: DWELL DUTY (RAW)

Post by Matt » Fri Oct 12, 2018 5:38 pm

B14 would just hold the last value for higher RPM. Newer Nissans only have 8 byte dwell tables FWIW

Post Reply