I will start with a parts list. You can use your existing ECM but will need to change your chip for one that matches your new engine and trans. You need to get a chip from the same year as your van. Reasons for this are the 92 will have a 700R4 trans. The 93-94-95 has the electronic version, which is the 4L60E. But the 95 chip cannot be used with a 93-94 trans and vice-versa due to changes made to the trans. My van is a 93 with a 4L60E with 3.42 gears. I installed a 95 305 TBI engine so I got a chip for a 93 C1500 with a 305, 4L60E trans and 3.42 gears. I just got lucky with the gear part. I would have used any chip regardless of the gear ratio.
So anyways, you need a chip. From the junkyard I got these parts:
IAC (idle air control) plug and as much wire attached as possible. (the wire part will apply to all connectors I list)
TBI unit, including the IAC, from your year van. It can be from an Astro\Safari or a full size van.
TBI injector connectors.
Cruise control servo, bracket and linkage.
EGR solenoid, connector and wires.
These are the things needed that are different between the CPI and TBI wiring. You will also need the basic stuff you need for a TBI engine. Basically, find a TBI V8 from any truck and get everything on it attached to the intake manifold. I also found that the full size TBI vans have braided stainless steel fuel lines that work perfect for this swap.
You also need to change out your high-pressure fuel pump for a TBI fuel pump.
Get some 14-gauge wire, solder gun and shrink tubing along with a nice length of 10-gauge wire for the coil.
First, the injector wiring. Use the existing pink and blue wires going to the single CPI injector. Splice in one of the TBI connectors to this using the same colors. Also, splice the white wire from the second injector to the pink wire. That is the 12 volts to the injectors. The remaining green wire is a little trickier. I will tell how I did it. It can be done different but mine is the end result of finding out my GM wiring manual was wrong. There is a valve on the CPI engines called the Variable Tuning Control. There is a relay associated with this. On the firewall on the passenger side up top you will see three relays. From right to left: Fuel pump, horn and variable tuning control (VTC). Remove, unplug and throw away. Cut the connector off. Cap off the pink wires. Splice together the dark green and purple wires. Tape it all off and hide it away. Back down by the engine you will find the plug that went to the VTC solenoid. It was on top of the manifold. Cut the connector off, cap off the black wire. What is left is the purple wire that you spliced together at the relay. Splice the purple wire to the remaining green injector wire. Almost done with these. That purple wire was supposed to go back to pin A9 at the ECM. The manual was wrong. It went to E3. Remove the wire\connector from E3, add a bit of wire to it to make it longer, and put it in A9 that has nothing in it. Your manual will tell you the pin outs of the ECM connectors. Done.
EGR solenoid. The original EGR valve is the Linear style. The V8 motors do not use it. Cut off the five-wire connector. Cap off the brown, purple and gray wires that are marked C-B-D on the connector itself. Splice the Pink (E) and Gray (A) to the same color wires on the EGR solenoid connector you got previously.
You will have an Air Intake Temp sensor. Cut and cap the wires. They are tan and purple.
IAC valve. Same wiring. Different connector. Cut off the flat connector and splice in the new square one.
Knock sensor. The V6 used two. The V8 uses one. Cut and cap either one of the original blue wires and just use the one that is left. You will probably need to lengthen it though.
Everything else connects the same though you need to lengthen some wires. I needed to lengthen the AC, water temp, knock sensor and coil power wire. The cruise control wires and hose were able to fit at the rear of the engine by simply moving them from above the master cylinder to below it.
The main harness itself is awkward to position. Most of it originally went to the drivers side of the engine. I put it over the passenger side and with a little work you can get most things to line up. One thing I did was to position the distributor so the connectors faced the passenger side as opposed to the original drivers side.
As a side note, I soldered and shrink wrapped all the splices I made due the fact that these wires go to sensors that are sensitive to voltage changes and felt this is the best way to achieve a good, long lasting connection.
WIRING COMPLETE
VTC RELAY WIRING
SPLICING IN THE INJECTORS WIRING
IAC VALVE SPLICE
