1227165 ecu with custom code much better than stock ecu. (Page 18/26)
chetw77cruiser NOV 09, 07:42 PM
That one will work fine.
Daviero NOV 18, 11:25 PM
Looking for a (1997-ish) Northstar stock timing map to use as a base in the 7165 $12P code.
I don't want to use the $A1 map from the 7730 I am replacing with Chet's 7165 idea - I don't know that the $A1 map is right.
Anyone?
Daviero DEC 15, 10:31 PM

quote
Originally posted by chetw77cruiser:

The 7165 will also do 8192 baud as long as a 10k resistor is used between aldl pin A and B.




Chet - a few clarifications and questions....

A 10K resistor between aldl pins A and B enables 8192 baud rate? This is not mentioned in the write-up that came with the NVRAM board or in notes by VL400 on PCM Hacking.net and is easily missed in your notes - please confirm this is right.

The knock filter on the original pcm memcal is used by the MVRAM board if no solder-on knock filter is installed?

When burning a tuned bin on the memcal for "limp-home" does the file have to be offset?

Where in the OSE12P code do you enable / disable the VE learn and alter the rate of learn? I see the the VE learn parameters but do you know of some write-up that will take the guessing out of how each learn parameter influences the learn function? ( I have copies of the Basic Tuning and Advanced Tuning of 12P ECM's but VE-learn is not covered in either document)

If the same bin is burned on the original memcal as is on the NVRAM, how do you know you are on "limp" mode? Does this condition register an error code?

I have my OSE12P bin revised enough now that I think it will suit the Northstar and I will install it in the new year - I am really looking forward to how it will work.

------------------
Daviero - 88 N* GT

chetw77cruiser DEC 22, 12:12 AM
Sorry for the delay, I have been busy lately.


quote
Originally posted by Daviero:
A 10K resistor between aldl pins A and B enables 8192 baud rate? This is not mentioned in the write-up that came with the NVRAM board or in notes by VL400 on PCM Hacking.net and is easily missed in your notes - please confirm this is right.


I have run this with and without the 10k with the same results. The code is hardcoded for 8192.


quote
Originally posted by Daviero:
The knock filter on the original pcm memcal is used by the MVRAM board if no solder-on knock filter is installed?


Correct, if the memcal is in place and has an appropriate knock filter. I will have to dig through my notes about the input pin for the knock sensor. It is a different pin than the stock 1227165 which uses an external knock filter.


quote
Originally posted by Daviero:
When burning a tuned bin on the memcal for "limp-home" does the file have to be offset?


If you are using a 27SF512, offsets are needed. If using tunerpro to burn through something like an autoprom, the offset should be taken care of automatically. If not, ofsett the file to the last half of the chip. 8000 to FFFF should work with the 512 style chips.


quote
Originally posted by Daviero:
Where in the OSE12P code do you enable / disable the VE learn and alter the rate of learn? I see the the VE learn parameters but do you know of some write-up that will take the guessing out of how each learn parameter influences the learn function? ( I have copies of the Basic Tuning and Advanced Tuning of 12P ECM's but VE-learn is not covered in either document)


The enable bits are in the Flag section of the bin definition. There are a couple for each of the MAP A/B. One is for wideband and the other is for narrowband. As for the other settings, there is some discussion on the pcmhacking forum, but I just played with them till I got to a point that worked for me. I do not use the learn function much at all because I tune differently, a bit more hands on so to speak.


quote
Originally posted by Daviero:
If the same bin is burned on the original memcal as is on the NVRAM, how do you know you are on "limp" mode? Does this condition register an error code?


The size of the code is larger than most of the memcal eproms gm used, so make sure it is 32K vs 16K (27c256 vs 27c128). Limp home will set the ses light and the engine will usually run, but not very well. If a code is set, it is usually a code 51.
Smooth DEC 26, 03:22 AM
Any chance of you offering a pre-programmed chip/memcal?
Somewhat computer illiterate.
I would like to enhance my 88 GT's 5 speed MPG, maybe add lean cruise.
Kerry
armos DEC 27, 04:20 AM
I just want to update/revise a comment I made about this back in 2012:


quote
Originally posted by armos:
I've been reading this
http://californiasmoginstit...Check_Procedures.pdf

and I found some good news and bad news.
Good news is, from what I can tell, in CA they don't connect to the ECM unless the car is OBD-2. They just look at the check engine light.
Bad news is, for those of us who only have an idle test, the inspector is instructed to separately test the EGR system using "procedure prescribed by the vehicle manufacturer." I don't know what data they have on that, or if they really follow through with it, but the test procedure in the 1986 service manual would catch an EGR that simply doesn't operate.
It's a little weird to me and hard to believe that they do this.. if they're going to all that trouble to function test the EGR, it seems it would be simpler to just do the dyno test like the city dwellers get.
I expect in most states the EGR wouldn't be directly tested, just the tailpipe, so for them this wouldn't be a problem.




Since that time, I've passed an idle emissions test with the EGR electronically non-functional. It would appear the inspector does the quick and simple test - open the valve by hand to see if it causes the engine to stumble. If that happens then they infer the system is working.
This is only relevant to people who don't have to take the rolling dyno test.

I'd be surprised if the inspectors in any state actually connect to the ECM on an OBD-1 model, but I guess it's possible. California doesn't do this, they only connect if it's OBD-2. So on an OBD-1 car they won't know what ECM is installed.

For people in rural California (and maybe other states) who are only subject to an idling test, one could almost use this ECM swap except for just one issue. Checking the ignition timing. The inspector will check to see if the ignition base timing is at 10 degrees. So the ECM needs to behave as expected when the A-B terminals are shorted. From what I've read, the 7165 does not react to the A-B terminals in the same way. 7165 requires you to disconnect a connector, which isn't what the inspector will be expecting on this model vehicle.
I don't know how much demand there would be for this, or how difficult it would be, but I wonder if it would be feasible to copy the A-B behavior from the 7170 or other similar ECM. That way vehicles that came factory with the A-B feature could keep it working while using this swap.
gtjoe DEC 27, 08:44 PM
Im have no idea if this could be accomplised via ecm programing, but with a normally closed relay and a little creative wiring Im sure it could be accomplished

quote
Originally posted by armos:


For people in rural California (and maybe other states) who are only subject to an idling test, one could almost use this ECM swap except for just one issue. Checking the ignition timing. The inspector will check to see if the ignition base timing is at 10 degrees. So the ECM needs to behave as expected when the A-B terminals are shorted. From what I've read, the 7165 does not react to the A-B terminals in the same way. 7165 requires you to disconnect a connector, which isn't what the inspector will be expecting on this model vehicle.
I don't know how much demand there would be for this, or how difficult it would be, but I wonder if it would be feasible to copy the A-B behavior from the 7170 or other similar ECM. That way vehicles that came factory with the A-B feature could keep it working while using this swap.
chetw77cruiser DEC 28, 02:33 PM

quote
Originally posted by Smooth:

Any chance of you offering a pre-programmed chip/memcal?
Somewhat computer illiterate.
I would like to enhance my 88 GT's 5 speed MPG, maybe add lean cruise.
Kerry



I can program chips and install into memcals compatible with this setup, but it will not be optimal for your vehicle. I have few modifications on my engine and then some. For the lean cruise, there are two fueling maps available at the flip of a switch enabling switching between MPG and normal or performance settings.

chetw77cruiser DEC 28, 02:37 PM

quote
Originally posted by armos:

For people in rural California (and maybe other states) who are only subject to an idling test, one could almost use this ECM swap except for just one issue. Checking the ignition timing. The inspector will check to see if the ignition base timing is at 10 degrees. So the ECM needs to behave as expected when the A-B terminals are shorted. From what I've read, the 7165 does not react to the A-B terminals in the same way. 7165 requires you to disconnect a connector, which isn't what the inspector will be expecting on this model vehicle.
I don't know how much demand there would be for this, or how difficult it would be, but I wonder if it would be feasible to copy the A-B behavior from the 7170 or other similar ECM. That way vehicles that came factory with the A-B feature could keep it working while using this swap.



The ecm does sets the ignition to a fixed advance when in test mode. Let do a little research on this and I will get back to you.

uhlanstan DEC 29, 04:50 PM
you can ajust the IAC but you have to use very small increments of ajustments ,, you can use thinner or thicker gasket,,you can sand down the gasket ,or use thinner which is the better option,, you need a new G.M. delco pick up coil to get best results 50/50 chance Pick up coil will improve idle
it seems you need karnac,or proper magic kharma to get the proper Idle
if you have one of the Brown ,(name Brand) IAC ,some of them are not up to snuff/specs,, they were sold by Advance auto parts a few years back