Need parts for 86 Fiero SE V6 (Page 2/3)
olejoedad OCT 16, 07:05 PM
Charlie, I think you're correct.
I remember hearing or reading that sometime in the last 31 years of Fiero ownership and wrenching on them.
I think they went to aluminium for the 86 model year.
Carlin OCT 17, 08:40 PM

quote
Originally posted by Vintage-Nut:

Your first photo is a Fastback Engine Grill/Vent
Your second photo is a Notchback Screen {without the grill/vent} which is the original type


TIP: Don't spray paint the grills/screens; powder coat instead


The computer isn't a problem; however, the PROM {Programmable Read Only Memory} chip MUST be correct for the vehicle {see the chart in the link}
https://gafieroclub.org/ECMgood/fieroprom.html#V6



so I looked at the sheet. how do I find the PROM number I need. there is a bunch of them that don't seem to connect to anything

I think it might be FBA1819. but I'm not to sure. I went 86-Auto-Federal and got that number.

[This message has been edited by Carlin (edited 10-17-2025).]

1985 Fiero GT OCT 17, 09:19 PM

quote
Originally posted by Carlin:


so i looked at the sheet. how do i find the PROM number i need. there is a bunch of them that dont seem to connect to anything



They all connect in horizontal rows, you start from the left, and pick what you have based on the options, then move right in that column to the next set of options, v6 or l4, then is it 84,5,6,7, or 88, then is it an automatic, 4 speed or 5 speed, then what size tires if applicable, then was it sold in California, or everywhere else in the US/Canada. Once you go through that, you'll have 2 numbers, the ECM number (which is the same for 86-8, hence it being less important), and the prom number (the actual chip inside the ECM that has parameters that must match the engine and transmission that you have)
Carlin OCT 17, 09:29 PM

quote
Originally posted by 1985 Fiero GT:


They all connect in horizontal rows, you start from the left, and pick what you have based on the options, then move right in that column to the next set of options, v6 or l4, then is it 84,5,6,7, or 88, then is it an automatic, 4 speed or 5 speed, then what size tires if applicable, then was it sold in California, or everywhere else in the US/Canada. Once you go through that, you'll have 2 numbers, the ECM number (which is the same for 86-8, hence it being less important), and the prom number (the actual chip inside the ECM that has parameters that must match the engine and transmission that you have)



I think i have the prom but how do i find a ecm with that prom. Ive been looking on ebay but everybody only labels the ecm number and not the prom number that is in it.
Vintage-Nut OCT 17, 10:27 PM
Some eBay sellers won't say the PROM {you need to ask}
Some sell the computer without the PROM {you need to buy the PROM separate}
Some will show the computer for "Engine/Transaxle"
Some show "Computer 1227170 AKYN" which AKYN is the PROM

GM sells remanufactured computers separate from the PROM

[This message has been edited by Vintage-Nut (edited 10-17-2025).]

82-T/A [At Work] OCT 18, 07:13 AM

quote
Originally posted by Carlin:

I think i have the prom but how do i find a ecm with that prom. Ive been looking on ebay but everybody only labels the ecm number and not the prom number that is in it.



This should help...
Vintage-Nut OCT 18, 09:46 AM

quote
Originally posted by Carlin:
so i looked at the sheet. how do i find the PROM number i need. there is a bunch of them that dont seem to connect to anything



Easy-To-Read Version
olejoedad OCT 18, 09:47 AM
Let me look in my ECU stash, I may be able to hook you up.
Carlin OCT 19, 12:36 PM

quote
Originally posted by Vintage-Nut:

Some eBay sellers won't say the PROM {you need to ask}
Some sell the computer without the PROM {you need to buy the PROM separate}
Some will show the computer for "Engine/Transaxle"
Some show "Computer 1227170 AKYN" which AKYN is the PROM

GM sells remanufactured computers separate from the PROM




btw I have been asking. nobody seems to know what the prom is. I've been telling them its the chip inside. Is there a way to find it without taking it apart since I know a lot of sellers don't want to just start taking things a apart and risk breaking them.
Carlin OCT 19, 12:37 PM

quote
Originally posted by olejoedad:

Let me look in my ECU stash, I may be able to hook you up.



If you mange to find one with the right PROM then let me know. Been on ebay but people take forever to reply back