I was wondering if it was possible to upgrade the ECM to OBDII or not? I noticed everyone upgrading their motors to the SC3800 and using the ECM for it. I was wondering if I could just upgrade to an OBDII port with the ECM? It was just for ease of use, clearing codes and stuff.. Can this be done easily?
------------------ Tim and Lynn 1987 Fastback GT in restore mode..
OBD-II also needs a camshaft sensor, in addition to crank position and knock sensor. The knock sensor is easy enough to install on a 2.8 V6 engine. But the 2.8 V6 doesn't have provisions for crank and cam sensors. You may be able to use an external trigger wheel for the crank sensor. But the cam sensor will still be a challenge. You may or may not be able to use the pickup coil in the distributer as an impromptu cam sensor; I'm not sure.
The 96+ 4.3 V6's were OBD2 and used a simple 3 tooth crankshaft sensor and a camshaft sensor in the distributor (it is 1 tooth or blocked 50% of the time). The SBC (and 4.3) share the same crankshaft snout shaft diameter, so this 3 position sensor will slide right onto the 2.8 between the timing chain and harmonic balancer (depending on available clearance). So with some work to mount the crankshaft sensor and swapping the guts in the fiero distributor housing, I think it could be done without much other work.
The system won't be as precise as the 24x or 58X crankshaft systems, but it will still have MAF & SD, sequential fuel injection, dual knock sensors and dual o2 sensors.
You just want to make sure the ECM you start with is tunable. Some of the 96-97 Vortec Truck Ecms are not supported for tuning.
Here is the crankshaft reluctor wheel:
Here is what the inside of the distributor looks like (just strip the Fiero dist of everything, install the 4.3 shaft, mount the sensor and make mount for the fiero rotor):
There's also a place on the trunk side of the V6 engine where a knock sensor could be installed. I believe some have also used the fan switch port for the knock sensor, since the ECM will control the fan. With these add-ons, you could also change over to the DIS ignition system, but the gains probably wouldn't be worth the input. Going to the OBD II isn't something that's usually done with a 2.8. It would be easier and the conversion apparatus is readily available to convert to the 7730 ECM and you could go DIS and achieve the same for less.
[This message has been edited by fierofool (edited 03-07-2014).]
as said yes, you can make this happen.... but I have to ask, why not just put in a 3400 roller block, all sensor spots etc are "built in" while your at it keep the alum heads and higher flowing intakes, uses all the same "bottom" mounts as the 2.8, bolts directly to the trans, just needs wiring, fuel, exhaust, and coolant routed, and an upper dog-bone mount added or modified to work. (and I think its rated at like 180hp? or something like that)
It would be a ton of work, but yes it's possible. Mostly in the wiring the new computer, but also mounting the newer sensors and making sure the ECM is seeing all the signals it wants to see, or having someone delete those from the programming.
As someone who doesn't know a lot about these things I have to ask:
what would be the gain of using OBDII?
on a side note, this got me thinking about having a permanent error code readout panel in my previous daily driver (which has an OBDI-through-OBDII-connector system). Flicking switches to read error codes would be more convenient than my current solution (a couple LEDs, a switch and a few wires all soldered together, I've misplaced it several times and stepped on it a few more)
The ECM would be light years faster, so it can better control idle and transient states. O2 sensor per bank for better fuel trim control. Knock sensors so you could be more aggressive with timing. Lastly, tuning in the OBD2 world is so much nicer than OBD1. Depending on what ECM you use, you might be able to run a newer electronically controlled transmission as well.
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
Wow.. so much info to digest. After consulting with my accountant (my squeeze) she came to the decision that it would be outside our budget for this restore. But she is providing all funding for the tools I need to complete the restore. Now, if I can get a welder dude to come over and do some small work I could move forward with this project.. Sort of bit of more than I can chew at this point.. UGH..
Thanks everyone for all the info that you've provided! You guys are the BORG of the fiero community.
------------------ Tim and Lynn 1987 Fastback GT in restore mode..
Wow.. so much info to digest. After consulting with my accountant (my squeeze) she came to the decision that it would be outside our budget for this restore. But she is providing all funding for the tools I need to complete the restore. Now, if I can get a welder dude to come over and do some small work I could move forward with this project.. Sort of bit of more than I can chew at this point.. UGH..
Thanks everyone for all the info that you've provided! You guys are the BORG of the fiero community.
you are a tad far away for me to drive down and help you with the welding, but I am sure there has to be a few members in your area who are also quite capable welders, maybe not as good as I am but good. hey I haven't put my hood on in years, but never seem to have a problem running a bead a lot better than most I have seen post of their so called welds here. some of the motor mounts people have posted pictures of they have welded scare the hell out of me.
Good luck
Steve
------------------ Technology is great when it works, and one big pain in the ass when it doesn't
But she is providing all funding for the tools I need to complete the restore. Now, if I can get a welder dude to come over and do some small work I could move forward with this project.. Sort of bit of more than I can chew at this point.. UGH..
