My fuel pump wont turn on. We had voltage to the pump so i replaced it. Nothing. We hard wired the pump with a switch in the connector for the fuel pump relay. Pump turned on. I bought a new relay pump still wont turn on. Pulled the relay back out and put the switch in and it would turn on and again nothing with the new relay. What did i miss? What do i need to check next? Could this have been a bunk relay that i bought?

 

What kind of relay did you get? If not OEM it may be bad; even an OEM may be bad for that matter. I have several relays I swap around to make sure. Does relay "click" with the key ON?

 

I got one from autozone. It says volvo and made in hungary. The relay doesn't click when the key is on. I had another one in my spare parts box but i didn't know if it was good or not. Is there a way to test the relay itself besides what i did with a toggle switch. I know im getting fuel when the switch is on because i forgot one of the copper o-rings on my fuel filter so i had gas coming out of it so i know the line isn't blocked. That realy controls both pumps the fuel pressure regulator and the idle valve so i couldn't get it to start with just the toggle switch otherwise i wouold have drove it like that lol

 

Is this a viable fix

 

can we back up? what car model/year is this on? older 240s had 2 seperate relays, one for the ECU, and the other for the fuel pump. newer 240s, 740s, and 940s have a single relay module that has 2 relays inside, and the last year or two of non-turbo 940's use a plain single relay for fuel pump, and use the 'radio suppression relay' under the hood for the ECU power.

 

Its my 82 244 turbo. I know its not the ignition because i have power to the relay but none coming out of it apparently

 

a standard relay has 4 pins. power to the switch, output of the switch to the load you're powering. power to the coil, control signal to the coil thats grounded when you want the relay to turn the load on.

on the later LH cars, there is a relay to power the ECU, this is turned on when the ignition is switched on, and another relay for the fuel pump which the ECU turns on when it sees the motor is turning over via the ignition timing pulses (hall sensor or crank position sensor). as I said, on most of these later cars both of those relays are in one module. Unluckily, I don't have 1982 240 wiring diagrams so I dunno how your car's relays are wired.

 

All right. Well im lost lol. All i did was drive to the gas station and put gas in and then it wouldn't start. At first it would start and it would idle at around 150-250 RPM's. When i would give it gas it wouldn't go beyond 1000 RPM's.

IDK if that helps come up with a solution or what to check next. I know that power makes it to the back so i don't have a broken wire. I know the pump works because i now have fuel to the filter and i could hear it turn on with the toggle switch. When i put the relay in nothing. Is there a way to test the relay to confirm that it's the relay besides just using my toggle switch

 

Also with having power to the relay wouldn't that mean if there is an ECU relay that "turns on" my fuel pump relay, then that relay should be good correct? According to my little diagram thing that i posted the fuel pressure regulator and idle control valve are powered by this same green relay for the fuel pump

 

withoutt he primary fuel pump, the car can' trun at all. CIS needs around 60 PSI fuel pressure to operate.

maybe you got some bad gas in your tank?

you can test a relay with some clip leads and a source of 12V for the coil and a multimeter.

standard 4-5 pin auto relay looks like...

(4 pin doesn't have 87A)

so, 12V power clipped to pins 85 and 86 (polarity doesn't matter), the relay turns on, so you'd read 0 ohms from pin 30 to 87. unclip the power to the coil, and pins 30 to 87 should be open circuit.

now, if you have the later style dual relay, its abit more complicated, as I said there's two relays inside those. there's a wiring diagram on the side of most of them,

 

Those arent the right relays mine has 6 pins and its big and green like this

 

messed up the first time

 

ok, that shows an 'amplifier' (or really, some sort of electronic circuit) and a relay. pin 30 is always-on power, direct off the battery, pin 15 is from the ignition switch (on in 'II' (run) and 'III' (start). circuit 31 is ground. 31b is 'grounded through switch' per DIN 72552, but I don't know what this is connected to on your car.

when the relay is switched on, both 87 and 87B are powered.

my guess is, the relay will switch on when both 15 is 'hot' (eg, ignition on) and 31B is grounded (some sensor or switch in the car, can't say what since I don't have the wiring diagrams).

 

31b goes to coil negative
We are going to go test it now ill let you know what we come up with

 

ignition coil terminal 1? ok, then that 'amplifier' block is looking for timing pulses, so it shuts off the fuel pump when the engine isn't turning over. thats so the fuel pump is shut off when the engine stalls, even if you leave the ignition on. mostly its a safety feature so in a crash, the fuel pumps not squirting fuel onto a fire...

 

So after chasing problems and waiting for parts to come in for 5 days it ended up just being an old car problem. When it first died at the gas station i immediately swapped out the fuel pump relay with an extra one i had in the car. When i did that it popped the neg wire out of the harness connector. When i was swapping in the relay i bought i saw the black wire sitting there and just figured well its an old car and sometimes with old cars you get wires that dangle so i didn't think anything of it. Last night when we started testing things we saw that the ground wire was not in the plug we pushed it back in cranked it a few time and it started to cough and then fired up.

Thanks for the info pierce you were a big help and i appreciate it a ton. Now i have that extra info to stick inside my volvo manual once i find it. I have a feeling i left it in my 87 wagon when i sold it lol. Thanks again