ECM upgrade (1227730) for stock 2.8 (Page 65/107)
mswenson289 JUL 02, 10:07 AM
Picked mine up at NAPA for under $5.00
If you need a p/n i will check tonight.
Mike
mswenson289 JUL 02, 10:25 AM
Ryan:
86 SE 3.4 4T60 7730 with EGR mod. Still fighting multiple issues so they may be related, I just don't know. At startup idle is about 1250 constant for 6-10 seconds then smoothly lowers to 900 as expected. After driving awhile hard downshifts (might be related to needed the adjustable modulator adjusted on the tranny) when coming to a stop idle is at 1300 till it comes to a complete stop like it is watching the vss signal and at 0, idle goes to 900 cough's, idle goes back to 1300- 1500 and the whole car surges a couple of feet. It is possible to do this upwards of 6 times for one attempt to stop, but mostly after the surge it returns to 900 and idles sometimes it just dies. If you slap it into neutral on your approach to a stop it will search a little but seldom dies. No error codes. I have cleaned IAC passages and TB. Disconnected TCC, have looked for a vacuum leak cold and warm. Does the ecm wait for the vss signal to stop assuming load is removed? Any ideas?
Mike
Pyrthian JUL 02, 10:56 AM

quote
Originally posted by MulletproofMonk:

Someone mentioned a tool to pull the wires from the harness, where can you get it? I tried a paper clip to pull the wires and it didn't work...

-Brian



yes, the tool, if you can find it is great - I couldn't. what I used was a hairpin. flat stock, scrape off ball at end, use flat side. was just the right size to fit in the little square hole, and hit the realease. tho, with the hairpin - you can go to far into the hole, and pass the realease. I expect the official tool changes sizes, or is marked in some way to not pass the realease.
MulletproofMonk JUL 02, 11:03 AM
Part number would be great. I may have to try and stop on the way home from work since they close at something like 3:30pm. They have good stuff but the have bankers hours...

Anyone have a picture of a digital EVAP?

-Brian
Darth Fiero JUL 02, 02:49 PM

quote
Originally posted by mswenson289:

Ryan:
86 SE 3.4 4T60 7730 with EGR mod. Still fighting multiple issues so they may be related, I just don't know. At startup idle is about 1250 constant for 6-10 seconds then smoothly lowers to 900 as expected. After driving awhile hard downshifts (might be related to needed the adjustable modulator adjusted on the tranny) when coming to a stop idle is at 1300 till it comes to a complete stop like it is watching the vss signal and at 0, idle goes to 900 cough's, idle goes back to 1300- 1500 and the whole car surges a couple of feet. It is possible to do this upwards of 6 times for one attempt to stop, but mostly after the surge it returns to 900 and idles sometimes it just dies. If you slap it into neutral on your approach to a stop it will search a little but seldom dies. No error codes. I have cleaned IAC passages and TB. Disconnected TCC, have looked for a vacuum leak cold and warm. Does the ecm wait for the vss signal to stop assuming load is removed? Any ideas?
Mike



You will need to hook up a scan tool to the ECM and get me some readings. First thing I want to see is closed throttle TPS voltage, then I want to know what the IAC position counts are doing when you are having these problems. I suspect you either have a vacuum leak or a mis-adjusted throttle stop screw (causing the IAC counts to drop to "0" and forcing the ECM to pull timing advance out to try to get the idle down).

-ryan
OH10fiero JUL 03, 05:08 PM
Was on your site looking at the posted info for the 7730 ECM and nothing showed up when I clicked on any of the options, not even a PDF download. Do you know when you will have that info up?
Darth Fiero JUL 03, 05:16 PM

quote
Originally posted by OH10fiero:

Was on your site looking at the posted info for the 7730 ECM and nothing showed up when I clicked on any of the options, not even a PDF download. Do you know when you will have that info up?




What URL/Page were you on when this happened? (please let me know so I can correct the issue if there is one)

What were you looking for, the wiring instructions download link?
Daviero JUL 05, 09:50 PM
About the 7730 and the speedo....
My speedo registers about 40mph at a walking speed, and bounces off the pin if I go much faster.
I am running a 7730 ECM reconditioned by Ryan Hess for a Northstar and have implanted a Quad-4 differential into my 5 spd Getrag transmission. I did not keep the Fiero VSS and opted to use the reluctor VSS from the Quad 4 leaving the notched wheel on the new diff. I have wired the ECM and the VSS per Ryan Hess' diagram, which is exactly the same as info in this thread and on Darth's site as far as the VSS goes. I rung out all the wiring to confirm correctness, and found that I had grounded the speedo low wire (purple) on the chassis ground near the ECM (G503 I think?). I removed the ground but the problem prevails.
I am running the buffer circuit, powered by C203-F, but cannot check it since I cast the wiring like a circuit board for mounting puposes. The only check I have left is to replace the buffer with a new one to confirm correctness, but I am confident the one that is there is correct.
What might be causing the problem? Do I have to flash the ECM for a different pulse ratio?
Dave

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

TiredGXP JUL 06, 01:10 AM
Hey Ryan,

I've been thinking about how speed density (SD) systems are sensitive to temperature changes, and the difficulties involved in properly adjusting bias values to help compensate for changes in intake air temperature. When running a MAF system, the MAF seems to handle air density changes due to termperature fluctuations much better than SD.

Are there any code masks out there for the 7730 that are compatible with a 3.1 DIS with both SD and MAF?

Cheers
OH10fiero JUL 06, 08:55 PM
From here on the forum I clicked on your homepage link and went to general swap info, the only two links that did not bring up a seperate page under that heading were the two links regarding the 7730 info. I wanted to view both pages to see what info I needed before caontacting you on a custom chip.