Ok, here's the problem...actually, it's a recurring issue for me, but something new has developed that has me stumped.
I have a '90 JDM ZC in my USDM '90 CRX. As so many others have done, I found myself a '91 (USDM) PM6 and chipped it, then burned a PM7 program (PM7ZCORG69.BIN) to it, and love it. After running a PG7 ECU for a few months, the PM7 program seemed to breathe new life into my engine. With the advent of Ghettodyne 1.4, I wanted to be able to use the new features (in particular, launch control and ECUControl) so I began splicing the maps from the PM7 proggy into the Ghettotune bin. There are a number of entries in the PM7 ignition maps that indicate more than 40 degrees of timing retard (starting with 2200 RPM/21 In Hg = 43.19 Degrees), however if you try to enter these values, Ghettodyne throws an error stating that you can't retard your timing more than 40 degrees. I notified Mike of this issue, which he planned to resolve in GHD 1.5. For the moment, the problem still exists (bugfix didn't make it to the release) and Mike claims it will be fixed in 1.6. Ok, enough background, here's where things get interesting...
Being impatient, I decided to try to work around ghettodyne and edit the values in question in hex...which worked. I was able to use the ignition > hex formulas and plug in the values to my rom, which opened fine in ghettodyne 1.5, and as long as I didn't attempt to change them, threw no errors. Excited, I burned this new bin to a chip and went for a test drive. All was well, no CEL or codes, until I noticed an odd problem. Everything would be cool, and all of a sudden my injectors would cut out (A/F guage went blank) and the car would start bogging like it was out of gas...I noticed this first at part throttle while heading up a hill. Oddly enough, if I opened the throttle more, the problem went away and injectors kicked back in. Initially thinking I had a problem with my fuel maps, I re-checked and they were cool. Went for another test drive, and this time paid attention to RPM and throttle position. I realized that my problem was directly related to the entries in my ignition maps, and whenever the situation (RPM + Load) called for more than 40 degrees of retard the car would take a shit...opening the throttle more would decrease the vaccum and take me out of the -40 range. Here are my suspicions:
1. I screwed something up while editing the bin in hex.
2. Ghettotune.bin is written in such a way that it doesn't allow for more than 40 degrees of retard, and is crapping out when it receives instructions to do so. Mike must have come up with this limitation in GHD 1.4 for a reason, and I'd like to know why as it may shed some light on this issue.
3. PM6 programs don't allow for more than 40 degrees of retard, while PM7 programs do. (shot in the dark)
I appreciate any feedback on this, as it's beyond my skills to investigate any further. If this doesn't belong in the development forum, I apologize ahead of time.
Thanks, -Z
|