LS1LT1 Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Ok so I have been fighting with this car for a couple of months now, T o begin with we had a 94 z28. Engine ran just fine and strong but the body was in pretty bad shape. So we purchased a 96 Camaro roller to put the engine and trans down in. It has been a long road of headaches bleeding and cussing and I am almost to the point of just setting the damn thing on fire. I have swapped the engine and trans in. I have swapped the computer on the passenger side firewall. It will crank over but not start. I am not hearing the fuel pump kick on at all. With some research here I saw I could test the pump with the wire on the pcm harness so I did and it works just fine, bring fuel all the way up to the test valve port. I checked the wires running to the coil, module and optispark and they show to have power. I do not have a multi-meter or much knowledge of ohms or any of that. I'm used to the cars of old that if it had hot and ground it worked for the most part. Im at my wits end on this and have no clue what else to check, I ran the fuses they are all good, all my grounds that I have found are in place and tight. I was told the VATS was disabled on the 94 computer so that shouldn't be an issue. If it helps at all the total fool that had the car before us thought he would be a shear genius and cut everything to get the motor and transmission out so that has been fun already, fuel lines, brake lines, old engine harness all of it, even the driver side abs wires were cut. All of that I have replaced from the now donor car. If anyone can give me any insight I would greatly appreciate it.

Thanks in advance!
 

·
Registered
Joined
·
5 Posts
Discussion Starter #2
Out of curiosity does the body control module under the passenger kick panel need to get swapped over as well?
 

·
Global Moderator
Joined
·
12,991 Posts
Welcome to the forum.

First thing you need to do is to download the 94 & 96 service manuals at the following link The service manuals have wiring diagrams, code numbers with troubleshooting. In fact a whole section of the manuals will be dedicated to engine electronics.My Files

The last owner & you have run into a bucket of worms. The 96 is an obd 2 computer system. It also has a body control module. In addition many wires are different between 94 & 96. That is why you need both 94 & 96 manuals. You have a lot of comparing of wires between 96 car & 94 engine. You would have been well served by getting a 95 z28, rather than the 96.

Don't know if you've got this far, but 94 & 96 use a different coil icm connector. The computer for 94 & 96 are completely different. Opti wire pigtail may have different connectors between 94 & 96.
Since you have the 94 computer system, you also need to wire in the 94 dlc connector. Than you need an obd 1 scan tool to read the codes stored in computer. 94 & 96 don't give up the codes by shorting dlc pins together.

Now for the codes. The 4 ignition biggies do not light the check engine light. DTC 16 low resolution opti pulse, disables the fuel pump, & fuel injectors. DTC's 41 & 42, both icm codes disable the fuel injectors.

If your vats security wasn't actually deleted, then starter, & fuel injectors won't work. But with the throw together of 94 & 96 parts, that could be part of your problem also.

Good luck as I don't usually recommend people without a strong auto electrics & electronics back ground. Also auto computer system knowledge is a must. This isn't the old days when hooking up a few wires did the trick.

Yes bcm needs to be in the car & wired correctly. Besides things like lighting, radio, pwr windows & door locks, bcm controls vats security also.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
I appreciate the response. If it helps at all the 94's engine harness is completely intact and was brought over to the 96 as well as the PCM from the 94, I was looking into changing the diagnostic port but had seen in other swap threads all that was required was the pcm as well as the engine from an obd 1 car.
 

·
Global Moderator
Joined
·
12,991 Posts
Having 94 pcm, & engine wiring harness is a good start. But you still have a bcm that's expecting communications with a 96 pcm. Without the bcm, many body functions won't work. And the theft deterrent module ( TDM ) & theft deterrent relay ( TDR ) are inbedded into bcm on 96. While tdm & tdr are separate modules on 94.

Both have to do with vats.

If you decide to eliminate the bcm, you will have to manually wire a bunch of different systems. While looking in 94 & 96 manual, see what difference in wiring that instrument clusters have.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
OK so I have went over all of shoeboxes connection info as well as looked over the manuals you provided, I have no idea what to try to do next. I guess its remove the entire damn harness out of the car and install the harness from the 94? Or I have a butchered harness from the 96 car and pcm that I could try to patch back with the 94 harness. Im at my wits end with this car and ready to just dump gasoline on the damn thing and set it a blaze for my personal; satisfaction. I can tell you this I will never work on or own one of these cars. I mean no offense by it but this is pretty damn ridiculous just for some wiring. How can the pinouts be that damn different?
 

·
Global Moderator
Joined
·
12,991 Posts
If you think these cars are complicated, try a new or nearly new car. They have 10 or more computer systems running things on the car. Wiring harness that makes 4th gen seem easy. And service manuals that have up to 20,000 pages. This is what is called progress.

Don't light your car on fire. Put it up for sale. I'm pretty sure there's someone out there who can get her back on the road.
 

·
Registered
Joined
·
4 Posts
Ok so I have been fighting with this car for a couple of months now, T o begin with we had a 94 z28. Engine ran just fine and strong but the body was in pretty bad shape. So we purchased a 96 Camaro roller to put the engine and trans down in. It has been a long road of headaches bleeding and cussing and I am almost to the point of just setting the damn thing on fire. I have swapped the engine and trans in. I have swapped the computer on the passenger side firewall. It will crank over but not start. I am not hearing the fuel pump kick on at all. With some research here I saw I could test the pump with the wire on the pcm harness so I did and it works just fine, bring fuel all the way up to the test valve port. I checked the wires running to the coil, module and optispark and they show to have power. I do not have a multi-meter or much knowledge of ohms or any of that. I'm used to the cars of old that if it had hot and ground it worked for the most part. Im at my wits end on this and have no clue what else to check, I ran the fuses they are all good, all my grounds that I have found are in place and tight. I was told the VATS was disabled on the 94 computer so that shouldn't be an issue. If it helps at all the total fool that had the car before us thought he would be a shear genius and cut everything to get the motor and transmission out so that has been fun already, fuel lines, brake lines, old engine harness all of it, even the driver side abs wires were cut. All of that I have replaced from the now donor car. If anyone can give me any insight I would greatly appreciate it.

Thanks in advance!
I went through the same problems because someone told me the VATS and vale mode was removed from a prom that I was working with , I would have the computer checked by a reliable source , if thats ok you saved that much time and you know its be taken care of , good luck .
 

·
Registered
Joined
·
14 Posts
Swap the complete harness from the 94 into the 96. Instument cluster and all. Obd1 & obd 2 are completely different. That sh
ould get you running. Then use your wiring diagrams to get everything else working. Or get another 96 harness and use that along with all the sensors and PCM/BCM Modules including the ABS wiring. Problem here is you got to go one way or the other. Or you could go deeper and make a totally new harness. I assume you want the fuel injection & optispark. So for get about your own new harness.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #10
Great news! I found the issue. Connector c210 the 4 prong one. Actually appears to not match the 96 version shoebox has on his website. Instead it matches the 95 version. So I jumpered the pink wire which was a keyed hot and it fired up! So now it runs but it is running way rougher than in the other car. It has new plugs and wires. But they are saying you can pull #8 plug wire and nothing changes about the way it runs. Any ideas?
 

·
Global Moderator
Joined
·
12,991 Posts
If you've pulled the # 8 plug wire off, while running, and nothing changes, here's a list of potential problems.

Spark plug bad, plug wire bad. Or distributor cap is bad on # 8 terminal. Other problems can be # 8 fuel injector not opening, something wrong with cylinder 8 valve train. Ar very low compression on # 8 cylinder.

Start with the easy stuff first.
 
1 - 11 of 11 Posts
Top