Wiring needed to run a Camarobird 3.4 fuel injection in a MJ

[coheed]

 

There’s very little info on what wiring is needed from the CamaroBird platform to run the 3.4 fuel injection in another vehicle using the stock PCM. These swaps are also very popular for MG’s, to the point that there’s one company that will make you a harness from scratch, but I could never find a list of what needed to be kept, so I made one. All of this applies to the wiring associated with 86 trucks and 94-95 automatic Camaros, as later trucks may have different colors and pin locations for the wires and the 93 Camaro has a transmission that isn't electronically controlled (though most of this info is similar if not the same).

 

Below are the connectors, how to identify them, and what wiring you need to keep from each one:

 

C100 black 10 pin, located in the top pass side of engine bay near the PCM

Cavities:

A: pink- power feed for injectors

B: dark green w/ white tracer- A/C relay control *

C: dark green- A/C clutch solenoid feed *

F: brown- power feed from coolant fan fuse

G: pink- power feed for ignition

H: dark blue- coolant fan relay control

K: pink- power feed for injectors

 

You can eliminate the C200 connector but keep the following wires. Located behind dash in the firewall (this looks like a bulkhead connector, but it isn’t, it's just epoxied into the firewall opening)

 

A1: dark green w/ white tracer- VSS input to cruise control module **

Any wire that feeds the under-hood fuse block and interior fuse #5 when the ignition is in the run position.

 

C210 black 4 pin, located behind pass kick panel

A: purple- theft deterrent relay to starter solenoid

B: black w/ white tracer- ground for ALDL port

C: orange- PCM 12v constant

D: gray- fuel pump prime connector

 

C215 black 11 pin, located on steering column

J: gray- w/ black tracer cruise resume/accel **

K: dark- blue cruise set/coast **

L: gray- cruise on **

 

C220 white 10 pin, located behind pass kick panel

A: red- power feed from cluster to alternator exciter (hot in run only)

G: dark green w/ white tracer- VSS for cruise **

J: dark green w/ white tracer- fuel pump relay control

 

C230 blue 10 pin, located behind pass kick panel

B: brown w/ white tracer- check engine light (switched ground from the PCM)

C: white w/ black tracer- diagnostic request signal for ALDL port

D: white tachometer- signal to gauges ****

E: dark blue- VATS 55mhz signal wire (wire bypass to this if not tuning VATS out of the PCM)

F: dark green w/ white tracer- A/C request signal *

G: pink- power feed from PCM ignition fuse

H: light blue w/ black tracer- brake signal input to TCC ***

 

And obviously any wiring attached to the engine, transmission, and fuel pump needs to be kept.

 

If you connect the 10ga yellow wire feeding into the theft deterrent relay (the relay that stops power going to the starter due to VATS behind the passenger kick panel) to the purple in that same relay connector going to C210 connector, you can bypass the theft deterrent relay. You can then pull that relay and all associated wiring. The yellow comes from the crank position in the ignition switch that will replace the factory green wire that goes to the starter relay on the MJ.

 

I extend the wire for the #5 interior fuse for the fuel pump relay into a slot that is powered with ignition in run/start in the engine bay fuse block from the Camaro. I also extended the wire for the #4 interior fuse for the PCM constant power and shortened the feed from the fusible link into the engine bay fuse block. Doing this completely eliminated the interior fuse panel. No other interior fuses need to be kept.

 

I chose to connect the dark green with a white tracer for the A/C request signal on the 3.4 harness to the light green with a black tracer from the truck harness. This is the wire the Comanche uses to send 12v to the low-pressure switch on the truck system and can trigger the Camaro PCM to turn the A/C compressor clutch on.

 

With a little trimming a PT Cruiser electric fan fits the 2.5/2.8 radiators pretty well. They have 2 speeds and you have to wire both power feeds together to get the high speed. Some of the OE style replacements are advertised as pulling over 2000 cfm, so a good one should keep the truck plenty cool. Also, if you use a program such as TunerCat you can lower the fan turn on/turn off temps. The stock fans come on at 228° and that seems like asking for issues given the cooling issues these trucks can face. Also, if you get a upper radiator hose for a 2.8 with A/C you can trim it to fit perfectly from the 3.4 t-stat hosing to the 2.8/2.5 radiator.

 

 

J, K, and L from the Camaro C215 will get plugged into yellow, red, and green on the MJ C215 connector respectively for cruise control commands. 

 

 The NP207 shifter is a different shape than later shifters, so I chose to get a later shifter from a junkyard and found a Novak cable kit used on FB as it was way easier than figuring out the math on a linkage since I was ditching the 207 for a 242.

 

The A904 shifter is a linkage style shifter, so I also decided to get a later style auto shifter and cable from a junkyard and use it instead of doing math. The shift distance is almost the same between the 87-95 MJ/XJ and the Camaro, however you’ll need to trim some on the backstop of the shifter to be able to reach the first gear position of the 4l60e throw. And because the 84-86 auto shifters are linkage based, the firewalls don’t have a hole for cable shifters. You will also need to cut and weld the cable brackets from both the AW4 and 4L60e to attach the cable to the case.

 

 

My truck was not wired from the factory to have a functional check engine light in the cluster, but I know some 86s were. As such, I just spliced a power tap for the 12v feed to that bulb and plugged it into the fuse panel and spliced the switched ground from the Camaro PCM to the other contact.

 

I have not figured out how to turn the reverse lights on the truck on with the new shifter. The previous AX5 had an internal switch, and the Camaro uses the PRNDL switch attached to the shifter. Still trying to figure that one out.

 

*: not needed if using MJ wiring for A/C

**: not needed if not keeping cruise control

***: not needed if using a manual transmission

****: only needed if using a tachometer

 

[89 MJ]

Great work!

[Greenjeans]

Great job, Thanks for the info!  If you had done this a few years ago, I may not have stripped all the FI parts, brackets etc off the Camaro 3.4 and left in the yard 😁.  I went with a carb mainly because I already had bought a new Weber…. Side note: I used a 700R4 and 241C.  I did also have to modify a ‘99 XJ shifter and cut the hole in the firewall for the cable.  Mine was a 2wd so I also snagged the ‘99 transfer case shifter and made my own linkage for it.  

[coheed]

1 hour ago, Greenjeans said:

Great job, Thanks for the info!  If you had done this a few years ago, I may not have stripped all the FI parts, brackets etc off the Camaro 3.4 and left in the yard 😁.  I went with a carb mainly because I already had bought a new Weber…. Side note: I used a 700R4 and 241C.  I did also have to modify a ‘99 XJ shifter and cut the hole in the firewall for the cable.  Mine was a 2wd so I also snagged the ‘99 transfer case shifter and made my own linkage for it.  

A 700r4 would've made my swap easier for sure. I went with the 4L60e that came in the Camaro and used a Novak adapter to run a NP242 on the back of it. Unsurprisingly that adapter was the most expensive part in the whole swap lol.

 

You never know, you may end up finding a 3.4 in a yard and could yank the injection system off of it. Idk what the actual power difference between a well tuned Weber 38/38 or a Holley vs the FI is, but one of the reasons I wanted it was going camping in the mountains and driving across the country the big elevation differences always killed what little power the 2.8 put out. Climbing up pikes peak a few years ago made the truck feel like it had 25hp, and obviously I'll have less of that with the FI.

[Greenjeans]

I could have taken the FI parts, harness etc with the 3.4 engine along with all the serpentine accessory drive etc for the $250 price at picknpull. But I removed it all and left it.   I hogged out my 2.8 intake primary hole and it runs strong with the Weber.  It was about a day to get all the timing and carb adjusting where it needed to be.  One day maybe I’ll get it dynoed…. I’m curious about the HP.   I did use the Camaro exhaust manifolds and just plugged the O2 sensor holes.   Other than that it’s all 2.8 crossed over parts.