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Eddy
I'm writing up a more detailed in depth build thread over on TGO: My build thread But, I'll put a few pics up here of progress as I go along.

Here's the day I brought it home:










Kind of pathetic looking, I know.


Here's how it looks as of today:















I gutted the interior this evening. I found a few small rust holes in the driver rear floor pan but now the rust has been ground out and the holes have been welded up.

Next is lining up the new fender, hood, and nose perfectly.
BigBadLou
I noticed that you're missing the "tard lip", aka rear spoiler. If the original is beyond saving, I got one you could use. Unless, of course, you have some cool fabricating ideas up your sleeve. smile.gif

Oh, and I also have your driver side trim piece - you know, the long one, the longest one, the one from the front wheel to the rear wheel. Not sure what it's called.

Just let me know.
And get her painted! smile.gif

Lou
Eddy
I have the center piece, but the bolts are broken out of it. I came up with some ideas for something different while walking through the junk yard today. I just have to take some measurements. I have the piece that you're referring to but they're both from 91-92. I want the 85-90 style. I have the interior gutted so I can spray the door jambs, but I'm going to get the body straightened up before I even get the paint mixed.
BigBadLou
My side piece is the old style.
It is silver/grey so it would match your current paint.


Let me know if you are interested.
89LS1
Which junk yard did you go to? Briggs? Do they have anything good up there right now? Been wanting to go but I don't want to slosh through the mud.
Eddy
Yeah Lou, I want it. Now I just have to find a match.


I went to the wrench-a-part east of Austin on 71. I went to Briggs around 7-8 months ago. They only had 1 thirdgen and wanted $100 for the tail lights. I love the wrench-a-part yards. Prices are listed and CHEAP. I got my 1LE brake setups for under $40. I got my complete 4th gen disc rear for $120.
BigBadLou
You want grid-style tail lights? I got a few. smile.gif Even one non-grid style. Let me know. (no rush)
Eddy
I bought a set of grid tail lights off of fleabay. But, there are a couple of chips in the edges of one of them that I didn't see in the pics when I bought them. I'm going to mod them somehow, I just don't know what I want to do with them yet. The amber sections have to go though, that's a no brainer.
Eddy
Don't we have some wiring diagrams around here? I can't seem to find them. The wiring on the LT1 swap wasn't the best and I have a few "issues" that I need to hunt down while I have it stripped down.

What doesn't work:

cooling fan

tach (it's stuck around 5500)

any HVAC controls

wipers

tonneau cover release

radio

cruise control


There might be more but that's all that I know of at the moment. I haven't checked fuses yet, but I know there are several wires that aren't hooked up to anything. I'm thinking seriously about ripping the harness out and just completely redo it.

Stephen
Link to the 3rd gen wiring diagrams
89LS1
And if there are any other diagrams you need that are not on the board let me know and I will get it for ya.
Eddy
Thanks!
BigBadLou
QUOTE(Eddy @ Dec 24 2011, 09:04 PM) *
What doesn't work:
cooling fan
tach (it's stuck around 5500)
any HVAC controls
wipers
tonneau cover release
radio
cruise control

Sheeesh, I love redneck engine swaps. "Let's rip it all out, Bubba, we don't need no stinkin' wires!"

Sorry to hear that you are stuck cleaning up the mess. No wonder they sold this thing cheap.

Cooling fan: try checking the green/white trigger wire - it might not be connected to the LT1 ECM. Ground the wire (KOEO). If the fan comes on, the circuit is otherwise functional.

Tach: is it stuck immediately after key-on? That's a tach problem, can be fixed. Does it move at all once the engine starts? No? Probably not even hooked up to the LT1 ECM.

HVAC controls: they have a separate harness coming from the firewall behind the block - might have been cut as well.

Wipers: very common mistake when swapping engines. The wires get cut often because they are in the engine wiring loom. De-de-deeee!

Tonneau cover release: tied into the engine harness for safety (don't want to release the cove while driving) via the P/N switch on the automatic shifter and the starter solenoid. Likely messed up by the swap. It is a pretty straight-forward circuit, though, nothing complicated. We have a blow-up diagram on the diagrams page.

Radio: Power wire? Fuse? Memory wire? Most radios require multiple wires with power to function. The PO might not have known that.

Cruise control - that again goes through the engine wiring harness and since it also needs the VSS signal, that wiring might have been cut as well. If this used to be an RS, did it have 305TBI before or the V6? That matters a lot when it comes to routing the wires for the VSS (good ol' Cheby). That will determine where to look for the original wires (if they still exist).

Let us know what (chewed up or cut off wires) you find. I'll try to help out as much as possible.
You have my number.

Lou
Eddy
I've spent most of the day taking the LT1 harness out of the car and removing unused wires. They did a real hack job of twisting wires and taping them up. I spent a long time re-splicing the connections with heat shrink. I lengthened some of the wires and re-routed others to get the engine bay cleaner and neater looking. I'm planning on trying to find some split loom tomorrow to run the wires in.

The car originally had the 305 TBI. I happen to have a spare 305 TBI harness from a 91 Camaro. Since all of that other stuff is in the engine harness I'm thinking about just doing the whole harness the right way by combining the two. What do you think, Lou? Would it be easier (for everybody but you) to just add in the parts of the TBI harness that are needed or tear them both apart and make one new harness from the two? The stock ECM and wiring is gone from the car.

I have just about everything in place right now but not plugged in.


This is how it looks at the moment.




I still haven't figured out how I want to mount the fuse box just yet. I really don't like it or the ECM (or whatever the technical name for it is) in the engine bay but I really don't have any choice.

Eddy
I did a lot of reading and thinking last night about the issues that I have with the car. I have a few ideas but I don't know how good they will be or if they'll even work.

cooling fan- it's wired into the LT1 PCM but it has never kicked on since I've owned the car. I had to rig it up to run constantly when I drove the car home. Since then I haven't driven it far or long enough to need the fan. If I can't figure it out then I might just have to wire it into the ignition.


tach- can I just run a new signal wire from the coil to the big connector on the fire wall? It's stuck on 5500 and has never moved since I've had the car.


HVAC- There's a plug on wired into the LT1 PCM that connects to the high side line on the A/C. All of the freon lines have been hooked back up and the wiring from the controls in the car to the HVAC box in the engine bay are still there except for one plug coming out of the box. I believe it has 3-4 wires in that plug. Is there any way to make a "stand alone" harness to get it working? Also, the vacuum lines for the controls have been removed completely. If I run new ones, where do I hook them to in the engine bay?


wipers- There was a replacement wiper motor in the trunk of the car. I don't know if the one hooked up is bad or not. It was wired in to the LT1 harness.


tonneau cover release- I'm thinking about just wiring it up hot.


radio- This will be an easy fix. I'll just run 3 new wires for hot, ignition, and ground if I have to.


cruise control- I'm thinking about just removing this completely. I have it in all of my other vehicles and never use it.


Other strange things I found:

I found that only 1 of the 2 O2 sensors was plugged in. The other plug was on the harness, just never connected. I re-routed it to the other side of the engine so I can plug it in. Could this be one of the reasons the car always idles high?

I completely removed all of the wiring for the transmission plug. It was never hooked up and I have a 700R4 with a cable speedo. Eventually, I'm going to convert to manual transmission. It shifts fine for now.

I really would like to get all the electrical fixed and working on the car before I seal up the harness. There aren't any issues with any of the exterior lighting. They're all still hooked up correctly.

As for the gauges, I'm really not sure if the oil pressure or the temp gauge are working correctly. I know the speedo works and the volt gauge do though.
2fast4love
Eddy if your still looking for parts for your camaro there are plenty here in Sa. The yards always have more camaros than firebirds which sucks for me, do know if you will find 1le stuff actually you probably never will. As far as the computer mounting on your car I also hate the engine bay mounting of ecms and msd boxes. Maybe you could try mounting it on the charcoal canister side of the front bumper, maybe make a cover and paint the color of the car make it blend in. Well good luck with your build!
BigBadLou
QUOTE(Eddy @ Dec 25 2011, 07:00 PM) *
The car originally had the 305 TBI. I happen to have a spare 305 TBI harness from a 91 Camaro. Since all of that other stuff is in the engine harness I'm thinking about just doing the whole harness the right way by combining the two. What do you think, Lou? Would it be easier (for everybody but you) to just add in the parts of the TBI harness that are needed or tear them both apart and make one new harness from the two? The stock ECM and wiring is gone from the car.

I think it's just a decision based on style preference. I could go either way.
Depending on why your windshield wipers don't work, you could splice in just a few wires from the other harness or you could replace the whole thing.
If you need to resplice many wires to lenghten them or to clean it up, it would be logical to just do it with the new unmolested harness.
If you need only one or two extra wires hooked up, I'd add onto the existing harness.

So it's your call, based on the work needed to get the thing done.
BigBadLou
Fans: don't wire them into the ignition. They draw too much power and there's a reason they use relays.
You can simply ground the green-white wire and have the fans come on with ignition via the relays.
It's a common misconception that circulates through TGO and it's not good because the fans draw upward of 20 amps from a circuit that is already undersized to run the coil and other accessories.

Tach: if it is pegged and doesn't move, it is very likely that it is dead on its own. You can try a different tach driver board and see if the tach wakes up. For that, you don't need to remove the whole cluster, just the trim. The driver board sits inside the cluster in the right lower corner (just below the tach) and can be pulled out gently. You could test with mine, if you want. Mine's dead on accurate (calibrated it myself on our company's digital equipment lol.gif ).

Wipers: huh, LT1 harness powering those? I frankly don't know whether the motors are interchangeable between the thirdgen and LT1 years and whether they spliced the wires right. The original TBI harness would help out a lot here.

Tonneau cover relase: be careful not to bump the switch on the highway, let's say when rolling windows down. That would prove to be a very costly mistake.

O2 sensors: sure, a disconnected O2 sensor will cause a lot of strange issues. It could be easily responsible for your high idle. Hard to say until it's plugged in.
How come you did not get a CEL? An unplugged O2 sensor should trigger it.

Gauges: the temp and oil pressure gauges require the 3rdgen sensors. If they did not keep those on the engine, you will need to get some and plumb them in. No other way around that. The gauges are incompatible with the LT1 signals from the ECM.

Hope this helps.
Lou
Eddy
As much as I don't want to I think I'm going to have to just pull everything back out and start from scratch by marrying the existing LT1 harness with the TBI harness. The car starts, runs, and drives great. But, I'm pretty anal about everything working. I don't want just another typical "bubba beat" thirdgen that is half assed. I want to get all of this fixed and working while I have the car torn apart....and time to do it.

Question:

Since I have the LT1 PCM to run the engine, do I need to put another TBI ECM back in the car to run the other accessories like wipers, HVAC, etc..? I think I might have an extra one or two in a box somewhere.

Also, I can't find an oil pressure sending unit on this motor. It has an oil level monitor and an oil cooler. And from what I've read, what I thought was a fan switch on the passenger side of the block is actually a second knock sensor.
BigBadLou
QUOTE(Eddy @ Dec 26 2011, 11:50 AM) *
As much as I don't want to I think I'm going to have to just pull everything back out and start from scratch by marrying the existing LT1 harness with the TBI harness. The car starts, runs, and drives great. But, I'm pretty anal about everything working. I don't want just another typical "bubba beat" thirdgen that is half assed. I want to get all of this fixed and working while I have the car torn apart....and time to do it.

Yup, I know your attention to detail so I kind of guessed you'd want to make your own harness, the right way this time. That way, you are in control of what wires are cut and which ones stay.
Jake did that recently, on his own, in just a few nights after work. Ask him, it's well worth the time, to know that it's done right.


QUOTE(Eddy @ Dec 26 2011, 11:50 AM) *
Question:

Since I have the LT1 PCM to run the engine, do I need to put another TBI ECM back in the car to run the other accessories like wipers, HVAC, etc..? I think I might have an extra one or two in a box somewhere.

The ECM in our cars controls only the engine. So no, you don't need it anymore. The wipers are controlled by the multi-function lever on the steering column and the delay timer is on the motor assembly.
HVAC is a stand-alone system as well. It just needs power. Also, the green compressor wire needs to be routed to the new LT1 ECM so that the ECM can command the fans on, IF you're using the ECM for that. If not, just leave it the way it is with the mechanical switches.


QUOTE(Eddy @ Dec 26 2011, 11:50 AM) *
Also, I can't find an oil pressure sending unit on this motor. It has an oil level monitor and an oil cooler. And from what I've read, what I thought was a fan switch on the passenger side of the block is actually a second knock sensor.

I'd ask Jake. He's done this recently and he'll remember where it was. I don't know the LT1 engines, sorry.

Hope this helps a little.
Gotta run.
Lou
89LS1
The oil pressure sending unit is mounted about where a distributor would go on a sbc. Rear top center.
89LS1
Holy crap, just saw your engine harness picture. What a mess. I would personally pull the harness and just fit/make it look nice and run the engine without any other crap. Complete the engine harness and have it looking nice but don't put your split loom stuff on yet. Then wire in everything else (wipers, hvac, etc..) that you want to run that the ECM does not control and have it run along with the engine harness (on top/next to) and once it is complete and nice then sheath both harness together in the same split loom. It will look as its just one harness but you will have two. That should make things much easier for you.
89LS1
Heres a pic of the last 5.3 I did (2 months ago)..If you just yank everything you don't want then redo it how you like its so much easier and you know whats what and its done right...
Just spread it out...Then start putting it back together one sensor at a time. I just start with one side of the engine at a time.

It looks overwhelming but its really quite simple.
Eddy
I have the harness back in the car. It looks great and is hidden very well. I had to give Lou a call because well, I'm an idiot and made a noob mistake. That issue is resolve now.

I'm happy to report that the volt gauge, oil pressure, gas gauge, and wipers are working!!!! I'm even getting some movement out of the tach now.


BUT, the damn thing WONT START! It turns over just fine but it won't run for some reason. I've triple checked all of the connectors and plugs. What could I be missing? Is there something stupid that I've overlooked?
89LS1
Are your injectors and coils getting powe? There is no vats or you have bypassed that correct? Don't mean to ask/say something already said but Lou probably knows more about where your at in the build than I do so I have to get a little caught up to be of much help. Has it run before?
Eddy
I haven't checked the power at the coil or the injectors yet.

Yes, the car runs...well, not right now. But, I drove it 100 miles home after I bought it. It usually cranks before the key is even turned all the way.

As far as the VATS goes, isn't that taken out of the PCM via programming?
89LS1
QUOTE(Eddy @ Dec 26 2011, 07:37 PM) *
As far as the VATS goes, isn't that taken out of the PCM via programming?


Yes, also can be bypassed with a resistor.
Eddy
I am getting power to the injectors. I'm getting power to the pink wire on the coil but not the white /black or the pink/black.
BigBadLou
QUOTE(89LS1 @ Dec 26 2011, 01:35 PM) *
Heres a pic of the last 5.3 I did (2 months ago)..If you just yank everything you don't want then redo it how you like its so much easier and you know whats what and its done right...
Just spread it out...Then start putting it back together one sensor at a time. I just start with one side of the engine at a time.

It looks overwhelming but its really quite simple.

Ivan, do not EVER post pictures like those again! Never EVER! smile.gif
Man, having your wife/girlfriend cut UNMARKED wires in a loom, that's dangerous. I hope you knew what she was doing! lol.gif

Lou
BigBadLou
QUOTE(Eddy @ Dec 26 2011, 07:09 PM) *
BUT, the damn thing WONT START! It turns over just fine but it won't run for some reason.

You said she ran before. So I would rule out VATS.
For an engine to run, you need fuel, spark&timing and air. I'd check for spark and spray some fuel down the intake to see what you're missing.

[in Jeff Foxworthy's voice] If your engine is giving you a lot of trouble and won't start, you might be a .... Chevy owner. lol.gif
Eddy
I hope I didn't fry the opti earlier today. The small wire on the starter was touching the other two and when I tried to connect the battery the car was trying to start.
89LS1
Wht/Blk is a ground so its a good thing you don't have power on that wire. The Pnk/Blk is a reference.
89LS1
BigBadLou
QUOTE(Eddy @ Dec 26 2011, 09:01 PM) *
I hope I didn't fry the opti earlier today. The small wire on the starter was touching the other two and when I tried to connect the battery the car was trying to start.

IMHO, the purple wire having power on it and the engine turning over should not be any cause for alarm or concern. The spark is on a different circuit and was unpowered and there should be no way of the power back-feeding from the purple wire into the ignition circuit.

I'd really try starting her with extra fuel in the intake and checking spark too. Got power to the fuel pump?
Eddy
Yeah, the fuel pump is on a completely different circuit than the engine. When I turn the key on it's singing pretty loud.

There is a plug on the top of the opti-spark. With ignition on I'm not getting 12V to any of the 4 wires in the plug. Could that be the issue? I'm done with it for the evening. I'll go back out and jack with it again tomorrow.
89LS1
Terminal C of your distributor connector should be getting power with the key on. If it is not then you have a cut or unattached wire in the distributor ignition feed circuit.
That would be the RED wire on the connector and it goes to pin 14 ecm connector C2. Your CKP also ties into the line. So if there is not a break in the line I would test the CKP.
BlackBetty
Hey eddy,

Sorry to chime in so late on this one. I'll try to bring my home made "LT1 Wiring Book" with me to work tomorrow. (ask Lou, this thing is invaluable when it comes to sorting out LT1 wiring issues). Feel free to call me and i can attempt to walk you through some of it. I'm with Lou, i wouldn't be so quick to condemn the optispark. everyone likes saying they are crap and points to it at the first sign of any LT1 engine trouble. I'd be sure to check the wiring first.

Like was stated in the previous post. The Opti has 4 pins
A) red/black, low res signal from pcm C2 pin2
cool.gif purple/white, high res signal from pcm C2 pin 20
C) red, ignition feed 12v from pcm C2 pin 14
D) pink/black, distributor low reference signal from pcm C3 (this wire splits off and also connects with the crank sensor, NOT THE RED WIRE)

I lengthened every pcm wire by about 2.5 feet so i could run the harness down through the passenger kick panel like the stock harness does and have my pcm tucked neatly inside the cabin. i don't like the idea of the car's most important electrical computer device sitting in my hot, wet, humid engine compartment. but thats just me. Another thing i did, i repined the factory fuse/relay block so i could run cooling fan relays, ac compressor relay, fuel pump relay, and a main engine harness relay off one spot and have all the engine related fuses in one location. now the under dash fuse block only runs the vehicle body electronics and lighting. and everything else is done with the under hood relay block i have hidden by the battery.

Also, I couldn't help but notice you mention that she idles high? How high? does the rpm's hunt? run smooth off idle? I just finished battling a high idle condition in my LT1 swap after almost 2 months of fighting!

here is a pic of the fuse block when i was in the middle of my wiring project.

here is how the engine compartment sits now. much cleaner smile.gif

Any questions just ask.
~JAKE (425) three5O-9O26
Eddy
Before I completely called it a night I checked for power to the opti. I'm not getting anything on the 4 prong plug that goes to it. I'm going to chase down the wire that's supposed to be hot and see what I can find.
Eddy
Ok, I checked the red wire from the PCM to the opti. It has continuity but no 12v with ignition on. I'm still hunting.
Eddy
I think I've figured something out. I removed several wires that weren't hooked to anything. In that process I screwed up somewhere. Luckily, I just pulled the wires out of the harness and cut them with 3-4" left hanging out of the PCM connectors.

I need to hook up C4 pin 3 and C2 pin 30. They are both PCM ignition positive. Where in the car do I hook those to? The C100?
BigBadLou
QUOTE(Eddy @ Dec 27 2011, 10:33 AM) *
I need to hook up C4 pin 3 and C2 pin 30. They are both PCM ignition positive. Where in the car do I hook those to? The C100?

Yup. Those two need to be powered by the ignition circuit.
Jake went as far as using the key to turn on a relay in his revamped relay block and that relay now supplies power to all the ignition components, without having to go through the car's interior. Just like Ford did it. (and guess who suggested it? wink.gif )
Eddy
One day I might do all of that. Right now I just want the damn car to start again. I can just splice those two wires into the pink wire from the C100 then, right? The pin out for 88 shows it as F4 ignition.
BigBadLou
QUOTE(Eddy @ Dec 27 2011, 11:04 AM) *
One day I might do all of that. Right now I just want the damn car to start again. I can just splice those two wires into the pink wire from the C100 then, right? The pin out for 88 shows it as F4 ignition.

I don't have the pinout for the 1988 C100 but the 1989 diagram shows ignition on F4, yes.
It should be coming out of the C100 on the engine side already. If it's not, you can pull it from the spare TBI harness and plug it in neatly. nod.gif
Eddy
Those are hooked up. I'm getting 12V to the opti plug now but still no start. I should just left the F-ing harness alone.

The fuel pump is singing away. I can actually hear fuel being pumped into the rails. I'm getting power to all of the injectors, power to the coil, power to the opti, power to the MAF, power to everything that is supposed to be getting power.

I'm fixing to just shoot it.
BigBadLou
QUOTE(Eddy @ Dec 27 2011, 11:29 AM) *
I'm fixing to just shoot it.

Some fitting poetry for this occassion:

Here I stand, broken-hearted,
praying that my Chevy started.
It did not and that is it,
I'll just shoot this piece of sh*t!

roflmao.gif
BigBadLou
QUOTE(Eddy @ Dec 27 2011, 11:29 AM) *
The fuel pump is singing away. I can actually hear fuel being pumped into the rails. I'm getting power to all of the injectors

Careful, power to the injectors does not mean that they will fire. The ECM controls the low-side of the injectors, it actuates them by grounding. So you will have power to the injectors with the key on but that doesn't guarantee that the ECM is squirting fuel.

Have you tried spraying brake cleaner or carb cleaner down the intake to start it? That would at least tell you whether the problem is spark or fuel. Also, pulling a plug and checking the spark color will tell you a lot.

Let us know.
And don't give up, she will start eventually.
Eddy
I screwed something up in the wiring somewhere. It started just fine before I opened this can of worms. I have a full 91 TBI harness in my garage and I know of at least two LT1 F-bodies at the wrench a part that I can get the engine harness from. Trying to clean up the mess from the swap is a major PITA. I'm to the point now where I'm almost ready to just go get an F-body harness instead of trying to deal with this Impala crap. All the swap info I can find online deals with F-body harness, not B-body. I have no idea how to hook up relays, or even where and what to put them on. It's all completely foreign to me and honestly, it stresses me the hell out.

I haven't tried spraying anything into the intake yet. I don't have anything here to spray. I'm going to check the PCM grounds that deal with the injectors. I might have screwed something up there. At this point, it wouldn't surprise me.
Eddy
I'm heading out to rip the whole harness out of the car. Then I'm going to tear it completely down and merge it with my extra TBI harness. While I'm at it I'm going to extend the wires to the PCM so I can put it inside the car. The B-body harness that I have puts the ECM right behind the driver side headlights and I don't like it there. It's going to be in the way in the future.

Hopefully, I'll find what is screwed up and it'll start again.
BlackBetty
Be sure to hit up shbox.com for all your lt1 wiring needs. Or if you want some more diagrams let me know. I have an entire book of then now I can scan and email some to you if you want.

-jake
Eddy
Update:

I decided to take the harness back out, break it down, and start from scratch. I'm at the point where I'm starting to put it back together now. I'll work on it a little more tomorrow after work.
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