I'm in the middle, well actually pretty much finished my swap from carb to TPI but i've got some issues.

The three wires that goto the fuel pump. Purple, black, and orangish. what is each one? I've traced them up to a set of connectors under the dash on the driver side but have been unable to find them going over to the computer side and i'm sure they have to get there. I'm just not sure which is signal, power, ground etc.

I'll probably have some more questions but i need this answered first and foremost. Thanks for any input.

 

What was the car originally? As in, from the factory?

Take another look at the orangish wire and make sure it isn't tan, as the power wire to the pump, at least on my car, was tan/white.

 

When I did my swap on my 87 LG4 to TPI, all the wires were there for the sending unit in the tank because it came with a Fuel Pump for the carb. BUT because the Dash wires were all different I swapped the dash over too, which made the install really clean, I did not need to splice a single wire

I am not sure this really helps you tho

John

 

You will have three wires going to the tank. +/- for pump and - for pickup. The pickup will go towards the gauge cluster. Pump will go to the ECM. try following it from the ECM back or tank forward. There is a connector that goes inside the cabin and snakes towards the front.

 

If I am not mistaken, the sender wire is a pink up under the dash (may look purpleish) Orange should be pump + and black should be Ground.

When I wired up my TPI setup on my 86 LG4, I ran a new wire from the pump to the relay and ran the main power for the pump from the battery to the relay.
At the tank, I just used the chassis as the ground for the negative wire from the pump.

 

thanks guys, i've got this figured out now i believe and i'm out to splice a few wires. If it fires up, you'll hear from me again in this thread and you'll deffinately have something to help with if it doesn't work as well lol

 

OK, fuel pump is going. Turns on for 2 seconds to pressurize the lines just like its supposed to....but still no go. Far as I can tell, the injectors aren't firing. They do not have power.

I checked the injector ground wires in the ECM, those are fine.

Problem comes back to my underdash connector again. the IP connector under the passenger dash. Is power for the injectors supposed to come through this? According to this wiring diagram pins G and B are supposed to carry a ignition activated 12 volts to the injectors...however i have another piece of information off TGO that says pin G is "from guage fuse; feeds air seclect valve, canister purged, air diverter, EGR" and that pin B is "ALDL pin G and fuel pump relay pin D".

I can verify that Pin B is wired like the quote above as i've given it power and turned on the fuel pump.

Please help me out. How do i get power to those injectors or how can i best test that they're getting it or not? As of right now, Pins G and B of the passenger side IP connector are missing from my car's wiring. I added the wires for them and, going by the diagram, hotwired them to the battery (through a fuse) for test purposes. I got no change.

damn thing starts up and runs for a second or two on starter fluid, but i would really like it to run on gas now heh.

Thanks guys.

 

anyone?

I just need to know where the 12v ignition source is that powers the injectors so that the ecm can ground them...

I'll buy a Noid light tomorrow and hopefully be able to sort out more info but i have no idea if its even wired slightly correctly.