OBD1.5 to I or II swap, anyone done it?

[ForcedFirebird]

I'm building a hybrid 3.4 for a 4th gen Camaro and am considering going with a GM ECM only because the customer has to pass a sniffer and the SES light has to be functional. I would install a MeagSquirt like what's going in my car, but EGR and SES light are still bugs in the system and this is for a daily driver, and I need the ability to tune.

So, my question is, has anybody done either swap, and how dificult is it? If it's a matter or using the stock harness and soldering the connector on (and wires on different pins) that's even better.

Any thoughts/ideas?

[1988GTU]

Well IMO using the obd1 will be great for not having a SES light since if and when it does pop on it's usually too late or egr malfunction. IE: I have had a MAf fail on my old 88 2.8 and didn't find out it was bad until I started to realize I had to fill up more frequently due to poorer fuel mileage. I also then found out at the same time it had a lazy o2.

[ForcedFirebird]

Well IMO using the obd1 will be great for not having a SES light since if and when it does pop on it's usually too late or egr malfunction. IE: I have had a MAf fail on my old 88 2.8 and didn't find out it was bad until I started to realize I had to fill up more frequently due to poorer fuel mileage. I also then found out at the same time it had a lazy o2.

So are you implying the OBDI is NOT the best option?

I need the SES light to be functional, or he will fail emissions.

[1988GTU]

I am suggesting using obd1 for the ease or no having a SES light or at least being able to 'trick it' . With using OBD1 the user will need to be more alert so they can attend to any problems if it should arise. OBD2 is more fail safe/emissions friendly.

[ForcedFirebird]

I can't have the light comming on during the test, and the EGR needs to be functional. They don't scan or anything, but the light need to work on start-up.

I'm more looking for what kind of problems I might run into during the swap. I also need to purchase the OBDII equipment if that route is taken, but if it's an easier swap, then it will be done that way.

[1988GTU]

I can't have the light comming on during the test, and the EGR needs to be functional. They don't scan or anything, but the light need to work on start-up.

Light? The EGR doesnt have a designated light, it trips the SES light when it's faulty or doesnt see the correct information. It can still be physically there, plugged in, yet disabled from the ecm so it doesnt see it or trip the code. If you know how to fine tune the car (which you more than likely know how to do) you shouldn't have a problem getting it to pass the E tests with flying colors. IIRC there is a guy that has a TGP with no egr in place and it actually passes nox better than most that still would have one on there tgp/ste.

[ForcedFirebird]

Light? The EGR doesnt have a designated light, it trips the SES light when it's faulty or doesnt see the correct information. It can still be physically there, plugged in, yet disabled from the ecm so it doesnt see it or trip the code. If you know how to fine tune the car (which you more than likely know how to do) you shouldn't have a problem getting it to pass the E tests with flying colors. IIRC there is a guy that has a TGP with no egr in place and it actually passes nox better than most that still would have one on there tgp/ste.

I meant the SES light.

What about the speedo etc? I hve no expeieance at all with OBD1.5, guess I need to look at some wiring diagrams.

[IsaacHayes]

Yeah OBD1 likely since that's what it already is. And going OBD2 would mean a 3800 pcm probably and I'm not sure if the crank triggers/etc are the same. IIRC the OLD 3800's were but not sure about the seriesII.

I would try to find the pin outs on both cars, the 94 and the 93-older and then do a DIS conversion on the older 93 ECM by uploading the appropriate bin. ($a1 comes to mind).

So take the pins of the 94, and re-pin/change connector for the older PCM with DIS alum head 3.1mpfi code and tune from there. That's what I would do.

BUT is the car an auto? If so then you'll run into not being able to control the electric shifted trans..... . You may be able to piggy back the MS or something as long as the factory ECM remains happy and thinks the engine is running fine. It just won't be controlling fuel or spark... May need a few extra sensors as some probably can't be shared but I bet it can be done.

EDIT: Only need the SES light to come on and go out with start up? Rig the light up to a simple 555 circuit timer to just come on for a few secs at start up and then run the whole thing with MS. LOL

[ForcedFirebird]

EDIT: Only need the SES light to come on and go out with start up? Rig the light up to a simple 555 circuit timer to just come on for a few secs at start up and then run the whole thing with MS. LOL

I actually considered that, might be the best option. Then I can just piggyback the MS and the ECM can control the rest of the functions.

[IsaacHayes]

If they don't test the ALDL to scan for codes then you'll be fine. Otherwise then they will see it's not responding and would fail it likely.