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Can I upgrade to OBDII and keep my 2.8? by Tooshea
Started on: 03-07-2014 02:11 PM
Replies: 15 (610 views)
Last post by: fierofool on 03-09-2014 12:36 PM
Tooshea
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Report this Post03-07-2014 02:11 PM Click Here to See the Profile for ToosheaClick Here to Email ToosheaSend a Private Message to ToosheaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hi,

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?

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Tim and Lynn
1987 Fastback GT in restore mode..

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Gall757
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Report this Post03-07-2014 03:37 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
An OBD2 computer relies on crank sensors and knock sensors, and who knows what else....so no, the 2.8 would not send those signals....

here is a thread discussing some of the technology.

http://www.fiero.nl/forum/Forum2/HTML/122271.html

[This message has been edited by Gall757 (edited 03-07-2014).]

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jaskispyder
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Report this Post03-07-2014 03:45 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yeah, probably not worth the effort. I find ODBI so easy to work with, as all you need is a paperclip to read codes.
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Blacktree
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Report this Post03-07-2014 06:01 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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fieroguru
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Report this Post03-07-2014 07:01 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
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):

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fierofool
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Report this Post03-07-2014 10:48 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
There is an aftermarket crankshaft sensor that mounts at the harmonic balancer. It is a bolt on system, similar in principal to this one.
http://blog.hemmings.com/index.php/2007/page/94/

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).]

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hookdonspeed
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Report this Post03-08-2014 01:40 PM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
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)
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RWDPLZ
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Report this Post03-08-2014 02:05 PM Click Here to See the Profile for RWDPLZClick Here to visit RWDPLZ's HomePageSend a Private Message to RWDPLZEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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PerKr
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Report this Post03-08-2014 06:31 PM Click Here to See the Profile for PerKrClick Here to visit PerKr's HomePageClick Here to Email PerKrSend a Private Message to PerKrEdit/Delete MessageReply w/QuoteDirect Link to This Post
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)
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fieroguru
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Report this Post03-08-2014 06:40 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by PerKr:

what would be the gain of using OBDII?


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.
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Spoon
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Report this Post03-08-2014 09:16 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I thought this upgrade was hashed out years ago and I don't remember the need for a cam sensor. Let me know if I missed something.

http://www.fiero.nl/forum/A...100421-2-079574.html

Spoon

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fieroguru
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Report this Post03-09-2014 07:46 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Spoon:

I thought this upgrade was hashed out years ago and I don't remember the need for a cam sensor. Let me know if I missed something.

http://www.fiero.nl/forum/A...100421-2-079574.html

Spoon



The 7730 ecm is OBD1 and the OP is asking about OBD2.
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Tooshea
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Report this Post03-09-2014 08:42 AM Click Here to See the Profile for ToosheaClick Here to Email ToosheaSend a Private Message to ToosheaEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.

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Tim and Lynn
1987 Fastback GT in restore mode..

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n7vrz
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Report this Post03-09-2014 10:57 AM Click Here to See the Profile for n7vrzClick Here to Email n7vrzSend a Private Message to n7vrzEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Tooshea: You guys are the BORG of the fiero community.


Resistance is futile. You will be assimilated with your Fiero.

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84fiero123
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Report this Post03-09-2014 12:00 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Tooshea:

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

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Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

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fierofool
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Report this Post03-09-2014 12:36 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
Tooshea, you might contact the Virginia Fiero Club to see if there's anyone in your area. http://www.vafieros.com/
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