Fun with a 3400 Fiero

[ForcedFirebird]

That's an OBDII ECM. You need to have OBDII tuning equipment.

[IsaacHayes]

I would seriously consider re-wiring it for OBDI. yes you can do OBDII but you need equipment that is expensive and you'll need to tune a lot to get it to run right with a 5spd since those PCMs never had a manual trans in them. Also, I'm not sure how it will interface with your speedometer. And you might have the VATS security, missing body control modules, 2nd O2 sensor, etc to tune out.

Going OBD1 means you could get a 5sp 3400 swap chip from someone drop it in and go. No tuning needed on your end. Or if you wanted it, its cheap to get the stuff to do so.

I would go with a 3.1 mpfi 93-older beretta, or 94-older cavalier harness and PCM. It's an inside PCM where the lumina PCM is underhood. The Fiero mounts the stock PCM in between the seats so going with the beretta/cavalier/etc 3.1mpfi harness is closer to keeping the PCM in the stock place.

If the original Fiero 2.8 harness was in the car, you could do the modifcation to go to the beretta/cavy/similar cars ECM.. using these instructions http://www.gmtuners.com/files/Fiero_V6_to_7730_DIS.pdf

[AaronGTR]

I'd stick with the OBD2 pcm personally. It is more advanced and should run the engine better. More flexibility for better HP and gas mileage and easily retuned. No need for chips like OBD1. Yes he would need a flash tuner, but once he has that then there are a lot of possibilities and changes can be made quickly and easily. Want different injectors? Change a number in the bin file and 60 seconds to load it and you're done. No need to remove the pcm, burn new proms add chips etc etc.

All the stuff to make it work with a manual trans, no secondary O2 sensor, all that.... simple as turning off some codes and doing a flash. It's possible to make it work without the BCM too, from my understanding it's been done before.

[IsaacHayes]

Running OBDI and an emulator, less than a second to make that change...
I'm just saying there is probably more work involved to to get it to run with a 5spd with OBDII. Won't you need to adjust the throttle follower and all that so when you clutch it it doesn't surge or die? I'd rather not deal with a BCM and security stuff IMO. But yes it probably will idle smoother with OBDII with the 24x cam sensor and all that.

[robertisaar]

"OBD2 should make it run better"

there's something i love disproving every time i fire up the monte... granted 1.5 is almost OBD2, without the catalyst monitor and it uses the OBD1 signaling protocall. other than that, its exactly what it is.

even without the "benefits" of a 24X and cam sensor and ,subsequently, SFI, the MC idles better than it ever has, JUST from swapping to OBD1.

and why do people make burning chips to be such a pain? it literally takes 5 seconds or less, another 10 seconds to pop the chip in, and you're done... and that includes me limping my ass around to do it.

[AaronGTR]

You still have to remove the pcm to put it in. In some cars that is a major pain.

[robertisaar]

You still have to remove the pcm to put it in. In some cars that is a major pain.

for some cars, depending on where the factory mounted them, yes.

i got creative and flipped them upside down in the MC and GP for some fast action swapping, but if you want to put the time into it, you can relocate them to wherever you want...

[ForcedFirebird]

There are also the chip extenders that can allow you to move the chip wherever you like.

OBD2 f-bodies came in manual trans

[IsaacHayes]

I wonder what is required to get 3800 PCM to run a 60* motor... Anything? Are the crank triggers the same?

[robertisaar]

they use a 3x and a 18x...