DaddyRunner

So I bought an 89' runner from a guy for cheap not running. The guy said he thought it needed a fuel pump so the first thing I did was pull the pump and test it sure enough it was dead. When I installed the new pump I tried it and it was a no go. At this point I get out my volt meter and check the plug and only get 2 volts so I back track to the COR I pull the relay and start testing pins.

So where I stand right now is I get 2 volts to the +B pin with the key in the on position and about 7 volts to the fp pin with the key in the start position.. Does anyone know what might cause low voltages to 2 pins? Or what I could check next?

Oh yeah its a 3.0 with an automatic.

rworegon

Not sure of engine:
https://www.yotatech.com/forums/f116...please-127934/

Similar issue, but on a 22re...there may be something useful though:
https://www.yotatech.com/forums/f116...ge-cor-235993/

The FSM may help you out too....
pg 58, item 9:
http://www.ncttora.com/fsm/1990-1995...emci/eng3r.pdf
http://www.ncttora.com/fsm/1990-1995...u/powersou.pdf
http://www.ncttora.com/fsm/1990-1995...e/troubles.pdf
http://www.ncttora.com/fsm/1990-1995...e/fuelpump.pdf

ThatGuy1295

Just a thought.

In some cases If a fuel pump burns up it can sometimes burn up the wiring between pump and relay. Not completely but just enough to wear theres loads of resistance. You could try testing the resistance from the fuel pump relay to the fuel pump. This only tests the resistance of the wiring between fuel pump and relay.

DaddyRunner

Thanks guys! So it turned out to be water in the fuse block behind the efi relay and a burnt out Cor. I have fuel now but no spark lol!! This rig had an msd ignition that I think may be the culprit because there is no power to the coil. I would like to just get rid of the msd butt am at a loss as to how to go about it doors the msd replace something out is outs' add on? If anyone knows about msd please give me a hand and thanks again for the links they helped alot.

vital22re

iTrader: (2)

Take a picture of your engine bay and lets see what you're missing.

mt_goat

While changing my fuel pump I noticed the factory wiring was very small gauge and showed signs of corrosion. I had read that fuel pumps are very sensitive to voltage drops so I ran all new wiring straight from the battery to the pump through a new Bosch style relay and triggered the relay with the old wiring. By triggering the relay with the old wiring you keep the ECU in control of the pump but when on it has the full power it needs.