no fuel

[mitsuman]

hello, i was wondering if someone could help me out. i did 4g63 swapp on my 88conquest. and i cant get fuel. i know the one side of my relay is working for spark but the other side for fuel is not. i have no power to the positive fuel feed wire. and i tried an other relay, its not the problem. i am working with a 92ecu that i had recapped because it had no spark first and now no fuel. its really starting to piss me off. but its gonna run one way or an other. could i run pump off of ign. switch? does anyone have a pin out for the relay? cause i really would like to get this thing started. any info would be appriciated. thanks

[Bill Hincher]

Relays are just a way to handle a heavy work load, there are two sides to a relay, the one side ( small wires) will be the on and off signal. when you turn the switch on the voltage will engage a small coil and that coil will engage a small electro magnet that engages the heavy work load side of the relay ( heavy wire side)........most fuel systems have a safty in them, the fuel pump only activates the relay when the engine is running or the key is in the 'start' position.....so the pump dont run when the engine is off and the key is on......its usually connected to the ' tach' side of the ignition coil or the alternater output for the ECU to sense the engine running.

Find the positive small wire going to the relay, use a Digital Volt Meter ( DVM) to see if you have voltage with key 'ON' engine 'OFF'.....should be zero......crank the car over........see if the voltage is present while cranking .......if it does, the relay is receiving power on the signal side........next find the voltage coming ' in' on the heavy gauge wire.it should be 12v BEFORE you crank the engine over........connect the DVM ACROSS the heavy side relay ( plug the test leads into the heavy ' load' side wire and the other test lead into the power output side ( to the fuel pump)........crank the engine.......IF any voltage is present when turning the engine over.........that is how much energy it takes for the relay to work ( voltage drop)..the relay is no good.......no voltage should be present...( .5v is exceptable)........if no voltage is present during the voltage drop test while cranking.......connect the test lead to the output ( heavy wire ) side and the other test lead to ground..crank engine over..if the voltage drops to zero.......it means the fuel pump is receiving voltage and using it...........it dont mean the pump is good....just that it is receiving voltage....if any voltage is present ( and you have a good ground)...the fuel pump has a 'voltage drop' which should be less then .5v.....so now you know you have a complete or incomplete loop from power source to ground............I can help with schematic's if you need it........maybe you might have to by pass the ECU and wire up a stand alone system for the fuel pump

Bill

[mitsuman]

bill, thanks alot for the info. and yes it would really help if you could give me some schamatics of the fuel pump circuits and pinout of relay. im very familur with doing voltage drop test and diagnostics, im a auto technician, but i work on chev and cad. and most mitsubishi stuff is greek to me. i just dont have the schamatics and pinouts. i think if i had them i would be alright. your help is much appriciated. thanks, greg.

[DJpowerHaus]

I used to have all that on the site.. .looks like its in a sad state right now though. I'll try to dig it up tomorrow.