------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Same box running a slightly different tune. The engine will run fine on either. If you wish to you can swap the PROMs (under the little panel held on with two screws) to swap the 'tune'. With the PROMs swapped they are identical.
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07:55 AM
White Spyder Member
Posts: 1047 From: Gluckstadt USA Registered: Sep 2007
They're not exactly the same. For example you can not swap the prom (chip) from the '88 into the '86 ecm. They are completely different internally.
Not true.
quote
Originally posted by sportcoupe:
The proms are not interchangeable (physically). Their sizes are different.
Also not true. The 86 and 88 V6 use the same ECM. The chips are swappable from 86, 87 and 88, as long as they're for the same tranny type. (If you use a 4 speed prom with a 5 speed, you might not get a shift light at the right time. Big deal.) The 86 and 87 V6 have a rev limiter. The 88 chip eliminates the rev limiter. Not a good idea IMHO. But they'll all swap.
The 85 V6 ECM (6169) is a different animal. The code mask is different. While the physical chip is the same (a 2732) the data is stored in different memory locations in the chip. The PROM WILL physically swap with later years. Just won't run the engine.
You CAN swap an 85 ECM into a later car, as long as it has the 85 chip with the correct tranny type. You also CAN swap a later ECM into an 85 V6 car, as long as it has the later chip programming. (The advantage to using an 85 ECM is that it will support a knock sensor. Good if you decide to do a turbo or whatever. The 85 did NOT come with a knock sensor, however.)
------------------ Raydar 88 4.9 Formula IMSA Fastback Read Nealz Nuze!Praise the Lowered!
[This message has been edited by Raydar (edited 02-20-2011).]
oh so now with that rev limiter.... i have an 86 gt auto and an 86 gt maunal 5 spd, having a rev limit would be nice im doing a 3800 on the auto so can i take the prom chip and put it in my manual and get a rev limiter on it?
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01:58 PM
sportcoupe Member
Posts: 329 From: Savannah, GA Registered: Oct 2010
Interesting... '88s use 2732 PROMs - 24 pins - the same as the earlier cars. I program chips. Have the software and the programmer.
I don't know where your "88" PROM came from, but it's certainly not stock. What is the service tag # on the ECM? It would appear that your stocker was swapped out for a different ECM. (That's not necessarily a bad thing.)
[This message has been edited by Raydar (edited 02-20-2011).]
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05:10 PM
PFF
System Bot
Raydar Member
Posts: 41580 From: Carrollton GA. Out in the... country. Registered: Oct 1999
oh so now with that rev limiter.... i have an 86 gt auto and an 86 gt maunal 5 spd, having a rev limit would be nice im doing a 3800 on the auto so can i take the prom chip and put it in my manual and get a rev limiter on it?
Not sure if I understand your question...
Use that PROM with a 3800? Nope. The 3800 requires a totally different PCM and PROM.
You can't swap an automatic PROM into a manual. Well... You can. But it won't idle right and will do some other odd things. If you have the stock chip in your 86 GT manual, it already has the rev limiter. Probably around 6200-6300 is the cutoff.
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05:17 PM
Raydar Member
Posts: 41580 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Below is an '86 prom I took from a junkyard next to my '88 prom. They are completely different size.
Your 88 prom is from a 4cyl ECM, isn't it? In which case you are correct, it uses a different size and type EPROM chip than what was used in the V6 Fiero ECMs.
1985-88 Fiero 2.8L V6 ECMs all used the same type and size of EPROM chip: 2732a (4kb size file). 1985 V6 1226869 ECM used the $24a code mask while the 1986-88 V6 1227170 ECM used the $24 code mask.
1984 Fieros all came with 4cyl engines and all used the 1226156 ECM and my info says that ECM used a 2532 EPROM chip.
1985-86 4cyl Fieros used the 1226864 ECM that my info says also used the 2532 EPROM chip.
1987-88 4cyl Fieros used the 1227748 ECM which used the 27C128 EPROM chip (16kb) which is physically bigger than the 2732a EPROM chips used in all V6 Fiero ECMs.
-ryan
------------------ OVERKILL IS UNDERRATED Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com
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12:17 AM
sportcoupe Member
Posts: 329 From: Savannah, GA Registered: Oct 2010
Your 88 prom is from a 4cyl ECM, isn't it? In which case you are correct, it uses a different size and type EPROM chip than what was used in the V6 Fiero ECMs.............
Yes, it was a 4cyl ECM. I thought that was what this post thread referring to.
[This message has been edited by sportcoupe (edited 02-21-2011).]
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06:44 AM
Feb 22nd, 2011
Raydar Member
Posts: 41580 From: Carrollton GA. Out in the... country. Registered: Oct 1999
