OBD 1.5 Tuning

[mrogersmike]

Not sure this is the right spot to post this but...
I just started working with the 60 degree v6's about a year or so ago and have used this site and others to get my 92 Rodeo something more than the 3.1 could give. So I found a 95 regal with a 3100 and did a swap using the old and new parts. I quickly found that the support for the OBD 1.5 (for lack of a better name) PCM was lacking compared to most others. I converted the 3100 from the FWD auto to a RWD manual that was TBI, so there was a need for some tuning ability and wiring diagrams.
I wanted to post that I was able to accomplish this cheap and easily with some hours of research and of course using the XDF and ADX now available (thank you to those involved in getting this available). I find the 1.5 has alot of capability and is easy to work with in comparison to the dsm's I have tuned in the past. I have no idea if there is any interest in using these pcm's, but I can say that flashing these is way easier than chip burning and extremely cheap. Like less than $75 bucks (plus a cable if you don't have one already) cheap. I have seen where the articles here have helped me. If there is any interest in doing this I would be willing to do an article to outline what I have done. It was mentioned to me that there really isn't any interest, but thought I would offer to see if I could give back to those who spent their time to post in these forums that have helped me.

Any need? Maybe too old a PCM?

[caffeine]

I've flashed a 1.5 PCM before. It's definitely not easier to tune than OBDI with a chip emulator, but cheaper and easier than using a chip burner.

[mrogersmike]

I should clarify that by easier I mean there's nothing to do to the pcm, like removing the memcal, installing adapters, etc.. making changes with an emulator is somewhat faster once setup I agree. But not enough to offset the extra work and cost upfront. Of course, that's just my humble opinion. I'm just offering help to anyone interested. I'm not saying one is better or worse, just a different option that seemed simpler to me.

[caffeine]

Definitely simpler. Cheaper than OBDII by a lot and supports SFI too. If it was easy to run with boost I might have one in my car.

[mrogersmike]

I'm curious as to the limitations. I was considering a turbo later on but have not looked into the pcm that far yet. It may help me decide to just go a different route other than boost.

[caffeine]

Unless you can write assembly or know someone willing to do it for you, you'd have to modify the tables in the xdf significantly to run a 2 or 3 BAR map sensor. It would never run as well as an OBDI code that's designed properly to work with a 2 or 3 BAR sensor.

Not saying its not possible but would be far from ideal.

[mrogersmike]

I see. I think I saw some maf stuff in there. Wonder if it would be possible to switch over?

[caffeine]

I know the LT1 PCM is very similar and runs a MAF but I don't recall seeing any MAF tables in the V6 XDF.

[mrogersmike]

I'm at work so can't say for sure. I've looked at so much stuff the last few days that I could be confusing it with something I read. I'll check tomorrow. It would at least be interesting to know. I have a 92 sbc tbi with a small blower that I'm thinking about going to port injection but the ecm only has 2 injector drivers so I almost would have to go stand alone. At least that's the extent of what I know at this point.

[caffeine]

For SFI it would have to have 6 injector drivers. OBDI ECMs can run 8 injectors off a single driver though.

[mrogersmike]

Well that's good to know. I had read elsewhere that I would have to add resistors to the drivers and they may not hold up over time. Thanks for the help. It's greatly appreciated.

[caffeine]

You generally only need resistors for low impedance injectors. There are a few OBDI ECMs out there that can run low impedance injectors.

[mrogersmike]

Ah, that's the difference. Thanks again. Guess I have to go earn my wages. Someone has to pay for it all.

[robertisaar]

i've considered adding in boost support, but at the same time, no one has ever asked for it with this PCM either....

MAF may be possible too(i would need to see if there are any pulse accumulators that can be used other than the VATS one), but again, no one asks for it.

[caffeine]

I'll ask for it if you're willing