Why does main relay buzz and gets no fuel? - Cars & Trucks

Find another relay with an identical part number(maybe the fuel pump relay)& swap it in place of the suspect EEC relay.See if the buzzing quits.If it does,the EEC relay is bad.There might be a ac WOT cutout relay or fan relay with an identical part number that you can use instead of the fuel pump relay.The fuel pump relay & EEC relay will both have to be in place in order for the engine to start.A relay should click when you turn the key on,but it shouldn't make a buzzing noise.BTW-the EEC relay is energized when you turn the key on and then it supplies ignition on power to the computer,injectors,solenoids and fuel pump relay.Therefore, if the EEC relay is defective, these components are Not going to work.If you don't hear the fuel pump prime when the key is first turned on,that's a sign the EEC relay is bad.One of the injector wires should have battery voltage, if the EEC relay is powering up.If your vehicle doesn't have a matching relay to the EEC relay(except for the fuel pump relay)just pull the FP relay out and slide it into place of the suspect EEC relay for testing purposes.If the buzzing noise stops,then replace the relay because there's no way to test if the car will start without having both relays in place.

swap your fuel pump relay with something like your horn relay but the relay is almost never the problem to check the fuel pump turn the key on and listen near the filler cap if the fuel pump buzzes the fuel pump will only buzz for 3 to 5 seconds check for fuel pressure at the fuel rail it could also be fuel filter stopped up or pressure regulator

Replace relay,if not it,you can take back and get a pump and some elbow grease.

Hi

it could be the fuel pump but with the cost involved I would look at other cheaper options before replacing the pump.

the fuel cut off was reset but have you checked the fuel pump relay, the relay is a small electromagnet type switch inside a small black or green box on the main fuse box. if this is working correctly then when you turn the ignition on you should here a slight buzzing noise or a click normally from the dash area. I do not have schematics for this vehicle so you will need to locate the fuel relay to rule that out. if there is no noise then the relay is not working, if there is a buzzing noise then the pump is functioning, it is difficult sometimes as one needs the other to work or at least give some indication of the fault.

Try the relay first and then go from there, you may be able to test the pump by fitting 2 wires from the fuse box, again it will make a buzzing sound if its working. Lastly try and remove the battery overnight that will reset the ECU or cars computer to factory settings in most cases.

Hope this helps, have a good new year.
Regards
Dan

Main engine relay is defective or possible fuel pump relay.
After a hot run turn vehicle off then turn it right back on and listed for fuel pump to buzz, If you can't hear it then go to schrater valve on fule rail. Put a rag around it , wear eye protection and with ascrew driver push the valve in and see if fuel comes flying out. If not you need a new pump.
Main relay is a little tricky to test. You basically have to bypass it to see if problem recurs . Or just buy one swap them out and see what happens.

There is a fuse and a relay , they are mounted in the fuse box up under the dash on the driver side.

it all depends on if the wire does or doesnt have power when u shut the key off, if it does the pump will run non stop even with the key out,i would suggest getting the relay working properly,also depending how u hook it up u dont want too much voltage runnin through the relay...u could melt it,hope this helps

This is going to sound stupid, but before you change the fuel pump relay, go back to the tank and give it a few good raps(rubber malet works great) if your pump comes on-the buzz, you need a new pump. also if after replacing the relay- if thats what you determine to be the cause and it still won't run- get your ignition module tested-it needs to send a sig to turn on the relay as a safety. oh and sorry can't tell you were the relay is.

sounds like the fuel pump relay is stuck on. find the relay and replace it. hope this helps mike

My volvo v70 has three places for fuses and relays, one under the bonnet, one on the end of the dash board on the drivers side, and one the boot on the left hand side you may find what your looking for in one of these places