First make sure you get the engine harness from the donor car. The best harness is from the 97-03 Pontiac Grandprix, most of the wiring is under the hood. Next make sure you have the Fiero's harness you will need some of it. TOOLS NEEDED, Wire stripers, Soldering gun, Solder, Heat shrink, Loom. Electric tape, propane torch for shrink. Start out by removing the looming and tape from your fiero harness and donor harness. Take and start connecting all the sensors and injectors. Make sure you remove all the rats’ nests of wires and try and clean up the mess. Make sure you have your wiring diagrams, you will need them. Take a lot of time and think about where everything goes and make sure you measure 2 times and cut once. It's a pain to have tons of splices. When you have the wiring laid out get your pcm connectors ready. You can start splicing in your pcm connections. I will finish the rest of the layout after I provide the pictures. Any Questions PM me. I hope to have a step by step with pictures. I think anyone can do this.
[This message has been edited by lowfierogt (edited 09-22-2004).]
Way cool! By the way, after figuring everything out, how about manufacturing these looms, all complete, to us salivating populous. This will open up a whole new opportunity for a new hungry Super Charged V-6 owner group. Plus you can make a dime or two yourself. If the wiring is all figured out in a complete package, Fiero guys would be doing alot more of these swaps.
Sincerely,
Kevin J. Sullivan
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12:40 PM
wetpoop Member
Posts: 921 From: Baltimore Maryland USA Registered: Feb 2004
The only problem with yor suggestion, is getting the connectors. for the 3800 motor. It might work better to send the original 3800 harness to Tony, and then he could make the alterations, and send it back. But buying all the connectors to make a custom harness would be extremely expensive.
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03:33 PM
1MohrFiero Member
Posts: 4363 From: Paducah, Ky Registered: Apr 2003
I am very interested in this, bump to the top. I'm assuming you use the 3800 ecm? I've never been quite sure about how this part of the swap works... well for any swap for that matter.
Matt
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08:08 PM
gumert Member
Posts: 400 From: Hunderton, NJ Registered: Mar 2004
I am very interested in this, bump to the top. I'm assuming you use the 3800 ecm? I've never been quite sure about how this part of the swap works... well for any swap for that matter.
Matt
Actually, the stock ecm is used. You just take the wires from the sensons of the 3800, and connect them to the stock connectors of the fiero ecm. It's actually quite simple, I am sure Tony will explain everything later and provide the schematics. Funny thing is, is that most of the wiring for the sensors of the two engines are color coded the same. I didn't want to hijack Tony's thread, just trying to help out.
[This message has been edited by wetpoop (edited 10-05-2004).]
Actually, the stock ecm is used. You just take the wires from the sensons of the 3800, and connect them to the stock connectors of the fiero ecm. It's actually quite simple, I am sure Tony will explain everything later and provide the schematics. Funny thing is, is that most of the wiring for the sensors of the two engines are color coded the same. I didn't want to hijack Tony's thread, just trying to help out.
Very much so. I'm Done with the wiring. I will make up a diagram on what wires go where for the ODB1 swap. I have done ODB1 auto, 4speed, 5 speed and starting on an ODB2 5 speed swap. Most of the colors of the wires are the same, as wetpoop said. The hardest part is laying out the wires and cutting them to the right size.
Anyone can wire there own swap... The hard part is making exhaust and your own custom dog bone. I did get more done on this car, pics tomorrow. I'm a little buzzed up tonight for pictures.
Anyone can wire there own swap... The hard part is making exhaust and your own custom dog bone. I did get more done on this car, pics tomorrow. I'm a little buzzed up tonight for pictures.
how about you help me wire and i help you fabricate stuff.. i have a mig welder, band saw, and a 4 axis CNC mill for aluminum parts.
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09:29 AM
Raydar Member
Posts: 40857 From: Carrollton GA. Out in the... country. Registered: Oct 1999
Actually, the stock ecm is used. You just take the wires from the sensons of the 3800, and connect them to the stock connectors of the fiero ecm...
Hmmm... If you're talking about an NA 3800 (as pictured above) I might be able to believe this. Maybe. The chip programming would have to be wildly different, though. If it's a SC 3800, I don't believe it for a minute. Sorry. The only Fiero ECM that even supports a knock sensor is the 85 V6 ECM. Even then, I'm pretty sure that it's not equipped to deal with a MAP under positive pressure. (>1 bar? Did I get the terminology right?)
actually the fiero ecm can handle a 2 bar when reprogrammed -
[EDIT] I had forgotten about that. See Kohburn's link in the following post.
quote
...I think wetpoop meant that the stock 3800ecm is used
I wondered about that, but it didn't read that way to me. That sounds more reasonable. My apologies if I misunderstood. I'll shut up now, and continue to watch. Thanks.
[lurk mode]
[This message has been edited by Raydar (edited 10-06-2004).]
Actually, the stock ecm is used. You just take the wires from the sensons of the 3800, and connect them to the stock connectors of the fiero ecm. It's actually quite simple, I am sure Tony will explain everything later and provide the schematics. Funny thing is, is that most of the wiring for the sensors of the two engines are color coded the same. I didn't want to hijack Tony's thread, just trying to help out.
hmmm interesting, thanks very much for the info. Let the thread continue!
Man what a birdsnest. I think pictures with wires like that scares most people away from doing a 3800 swap. I have done two 1997 to 1995 wire harness conversions, and neither time did I use any of the fiero harness and neither time did I unravel the entire harness. I left everything in tact, and it makes it a lot easier to work around.
All you need is the power distribution block and the engine harness. The engine harness plugs into 1 of the 3 sections in the bottom of the power block. Then you splice the red white and blue connectors one wire at a time in place of the clear and blue obd 2 connectors. 99% of the pcm circuits are the same between the obd 1 and 2. (that means they have the same circuit number (wiring diagram) and wire color). Now, just splice the pink wire on the coil pack with a jumper that goes to C3 on the C500. This is the ignition wake up power wire. Now hook up the power that goes to the little junction block under the c500, to the power lead on the distribution block. This gives the wire harness and pcm power. Now hook up the neutral saftey switch like stock. Next hook up the fuel pump through the stock circuit at the c203 so you will have fuel. Now the engine will start and the car will run and drive, just wont have any gauges or anything. Thats the easy way. Takes me about 6 hours start to finish, including splicing the pcm connectors.
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03:24 PM
Oct 8th, 2004
birdpoo Member
Posts: 251 From: 33N,117W, sunny, no snow or road salt ever Registered: Sep 2001
Man what a birdsnest. I think pictures with wires like that scares most people away from doing a 3800 swap. I have done two 1997 to 1995 wire harness conversions, and neither time did I use any of the fiero harness and neither time did I unravel the entire harness. I left everything in tact, and it makes it a lot easier to work around.
All you need is the power distribution block and the engine harness. The engine harness plugs into 1 of the 3 sections in the bottom of the power block. Then you splice the red white and blue connectors one wire at a time in place of the clear and blue obd 2 connectors. 99% of the pcm circuits are the same between the obd 1 and 2. (that means they have the same circuit number (wiring diagram) and wire color). Now, just splice the pink wire on the coil pack with a jumper that goes to C3 on the C500. This is the ignition wake up power wire. Now hook up the power that goes to the little junction block under the c500, to the power lead on the distribution block. This gives the wire harness and pcm power. Now hook up the neutral saftey switch like stock. Next hook up the fuel pump through the stock circuit at the c203 so you will have fuel. Now the engine will start and the car will run and drive, just wont have any gauges or anything. Thats the easy way. Takes me about 6 hours start to finish, including splicing the pcm connectors.
Not to criticize your or anyone else's work, but I have seen the 3800 swap done this way and it looks cheap and ugly in my opinion. Taking the time to splice the wiring and make the wiring and loom look presentable makes all the difference in the world when you open the deck. I have seen batterys and distribution blocks mounted in the trunk area and it just looks nasty, and hastily done. Again this is just my opinion. I am sure Tony will update this thread with the final schematics shortly. Hold in there guys.
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06:40 PM
PFF
System Bot
Nov 14th, 2004
John Boelte Member
Posts: 1012 From: Indianapolis, IN, USA Registered: Jun 2002
I found using a piece of plywood to simulate the firewall helped a lot when shortening all the wires on the donor car harness and tying into the Fiero C500 connector. I mounted the plywood on a dowel through the front cradle bushings so I could flip it up into firewall position or down for work access. The fuel pump and A/C relays can also be posiioned on the plywood to simulate their actual postion in the car. I did it on a Quad 4 but the concept is the same no matter what engine you're swapping in.
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04:01 PM
Riceburner98 Member
Posts: 2179 From: Natick, Ma, USA Registered: Apr 2002
Heeey.... that's a good idea Sanderson! I just kind of "eye-balled" the area where I wanted my plug, and I definitely left too much slack.. I have an extra loop of loom at the firewall that looks like POOP in my opinion, some day I'll have to re-wire. The simple things are the most overlooked it seems! I'll keep that one in mind if I ever go insane and decide to do another swap...
------------------ Bob Williams Multi-colored '86 Mutt, a work in progress! (3800SC installation almost done... I drove it!!!! AAAAAAAAAAAGGGGHHH!!! This sucker is FUUUUUUUUUUUN!!! :) )
Ok, This is the latest on the wiring and my last swap.....
My wiring harness was done and I could not get my injectors to fire. I thought my wiring was bad so I sent it to PBJ to rewire. Well when it cam back it still didn't run. I tapped on the injectors and now the car runs fine. Anyone can do there own wiring, make sure your injectors fire. Use a test light and or tap them... This set me back 4 weeks. My next swap is in the works.
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10:03 AM
PBJ Member
Posts: 4167 From: London, On., Canada Registered: Jan 2001
Hey, good to see you got it running, nothing like a little hammer to tap those injectors back free again. Also nice to hear your harness has worked out for you in the long run even though it has had a bit of a trip on its own
Another note if your car starts running rough again shortly after you get some miles on it I would have those injectors sent out and rebuilt or replaced.
Another note if your car starts running rough again shortly after you get some miles on it I would have those injectors sent out and rebuilt or replaced. Pete
Yeah like Pete was saying, On any used engine that a swap is about to happen with the injectors should be cleaned if nothing else. that gas can make a injector cloged or worst. At the same time check the O-rings for wear or brittleness!
------------------ 98 3800SC, Getrag 5sp. only one in Austin Texas and surrounding areas
Hey, good to see you got it running, nothing like a little hammer to tap those injectors back free again. Also nice to hear your harness has worked out for you in the long run even though it has had a bit of a trip on its own
Another note if your car starts running rough again shortly after you get some miles on it I would have those injectors sent out and rebuilt or replaced.
Pete
Thanks pete. Good work on the wiring.
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10:21 AM
turbo86se Member
Posts: 2098 From: Carroll Valley, PA Registered: Oct 1999
