Super mud
NAXJA Forum User
- Location
- Bel Air Maryland
After doing a crap load of troubleshooting and electrical diagnoses, I've come to one last idea which I would like to check.
First of all, the indivisual wire which runs from the computer to the coil in the relay is not being grounded by the computer which is causing the relay to not switch on and run the pump. After checking the wire at the computer (note its labled orange/black for 87-90 cherokee) I determined the computer was not opening the ground. So i assumed the computer was bad and replaced. After replacing it still no luck and now I had no idea what could be causing it. Now I relized it must be something telling the computer not to switch on the fuel pump relay but I don't know what this would be because from what I've understood the fuel pump stays on the whole running time but after the 1st few seconds the Ballast Resistor drops the voltage and then the EGR (evaporatic canister soilenoid) controls the amount of gas return to the tank from the fuel rail.
I still have to check some more random stuff but as of now I'm stumped still. Theres not much else in the schematic that is helping.
Also whatever is controlling this will reset its self over time so the relay will flicker on and off for a few seconds and then not do it again till turning the key off for a while and then turning it back on. Any help would be nice, i'm trying to provide as much info as possible, If you'd like to see the schematic I might be able to scan it also. thanks
First of all, the indivisual wire which runs from the computer to the coil in the relay is not being grounded by the computer which is causing the relay to not switch on and run the pump. After checking the wire at the computer (note its labled orange/black for 87-90 cherokee) I determined the computer was not opening the ground. So i assumed the computer was bad and replaced. After replacing it still no luck and now I had no idea what could be causing it. Now I relized it must be something telling the computer not to switch on the fuel pump relay but I don't know what this would be because from what I've understood the fuel pump stays on the whole running time but after the 1st few seconds the Ballast Resistor drops the voltage and then the EGR (evaporatic canister soilenoid) controls the amount of gas return to the tank from the fuel rail.
I still have to check some more random stuff but as of now I'm stumped still. Theres not much else in the schematic that is helping.
Also whatever is controlling this will reset its self over time so the relay will flicker on and off for a few seconds and then not do it again till turning the key off for a while and then turning it back on. Any help would be nice, i'm trying to provide as much info as possible, If you'd like to see the schematic I might be able to scan it also. thanks