[While I am new to El Camino Central I am on my third El Camino. I have an 85 with 305. Have an 89 Firebird with 305 tbi and OD auto trans. for a donor car which is complete. I'd like to use as many parts from the firebird as possible to keep costs down. Has anyone tried seperating the fuel injection wiring out and using rather than buying an aftermarket harness? Is it worth the effort? What about the fuel tank, pump, transmitter assy? The car has VATS-what about by-passing it? Any and all comments or suggestions will be appreciated.

You can seperate the wiring and rework the factory harness. I have never done a TBI harness though, just LSx harnesses. I know the wiring for the el camino side, but I don`t know the TBI side. You might find directions for that on www.montecarloss.comI know that in the technical section they have instructions for wiring in a TPI harness but I`m not sure if they have directions for TBI too. For the fuel system the easiest way is to get a fuel tank for an EFI 4.3L V6 El Camino, and the sending unit for that tank. The sending units are difficult to find used and kinda expensive from the dealer. Then just put the fuel pump from you donor camaro onto the EFI sending unit for the El Camino tank. For the VATS you might be able to delete it from the computer with the proper software, or just run a VATS bypass box, there are a few companies that sell them or you can find plans to build one on the internet.

Thanks for the reply G-body. Checked that site but no tbi info. Still interested in this as I also have an 86 Monte Carlo SS that will be a candidate for conversion once I get a good basic plan figured out. Plan is to do the El Camino first as a test run as it is a little rough around the edges anyway.

Since you are interested in TBI, the attached URL is a pretty good read onthe subject.

TBI INFO (http://www.goingfaster.com/spo/tbi.html)

Enjoy

Good info. Thanks darbysan.

And VATS bypass modules are commonly available on ebay.

You can also build a VATS bypass if you are electronically inclined
http://fp.enter.net/~rockcrawl/passkey.html

I believe that the TBI systems are PASSKEY systems. So I think you would want the 30kHz signal.

Thanks G-body. I think I can handle the wiring harness but electronics are not realy my thing. Guess I will have to buy ready-made.

An alternative solution to the pass key system (if that's the one with the chip located in the key) is to measure the resistance of chip in the key with an ohm meter. Then go to the local Radio Shack and purchase a resistor with the same resistance value as the key. The last package of four resistors cost me $1.27. Then find the two wires coming out of the steering column from the ignition key switch, cut the wires, and solder the resistor between them on the dash side of the wires. ( I belive one wire was black and the other white) This was a permanent fix to my wife's old 91 Buick that wouldn't start because the switch was wore out.

The resistor solution would work, but I think you would also have to keep the body control module too then. I know that on the newer (LT1, LS1 etc.) engines have the anti theft signal controlled by the BCM. I think that even the TBI motors have a seperate BCM.

I did a little digging around, and I don`t think you even have VATS on your system, I think that only the TPI systems had it in 89. But I am not 100% sure. Do you have wiring diagrams for it yet? If you do, I would be able to tell you for sure if I looked at them.

The resistor trick would be an easy fix. It measures 6K ohms. Is this the right range? What is the" body control module"? I don't have a wire diagram for this car. I only say it has VATS because the key has a resistor in it.

Somebody correct me if I'm wrong, but I don't believe the 89 cars had the body control module in them yet, so you shouldn't have to worry about that.

A 6 ohm resistor should do the trick for you if that's what your key chip read. Just go to your local electronics store and purchase a package of them. (usually packaged in fours) It's a quick and simple fix to something that is quite frustrating....

Have you checked the # on the ECM?

Based on the year (89) if it is 1227747 you may not have that much trouble with simply swapping out the ECM and changing a few wiring entry positions. It is easy to pull the wires at the ECM and switch positions.

I am not sure if the 89`s used BCM`s, I never really looked into TBI stuff too much. Does anyone have wiring diagrams for an 89 TBI?

Pulled the engine and trans. out of the Firebird today. After looking at the wiring harness in more detail I think that although using it would be possible and might save a few bucks an aftermarket harness from someone like Painless would end up as a much better finished product. I'm saving all the sensors hoping that I can use some of them with the aftermarket harness. If anyone has experience with harnesses from any manufacturer I'd like to hear your opinion.