I recently purchased a 1984 244 Volvo DL, I believe it has the LH Jet-tronic injection. I don't know a whole lot about the cars past, other than it has new catallytic converter and exhaust/muffler. The car has 210k on it, and has been a gem for three months, all of the sudden I was driving it a short distance 5-6mi (several stop and go lights) to work and I noticed only twice in accelleration a miss or hesitation??? About an hour or so later I drove home and immediately while trying to accellerate the car was hesitating very badly under a load, I nursed it up to speed but had trouble going about 2500 rpms. The car continued to hesitate under a load until I got home. I suspected a fuel filter, pulled the fuses and ran the car out of gas to depressurize. I replaced the fuel filter, tried to restart the car only to have it run very briefly and run out of gas again. I checked fuses, and tested the pumps by jumping the terminals on the fuse center (drivers side kick panel). I also tested the pumps by jumping the terminals on the relays, I suspected the relays to be bad, replaced both the system relay and fuel pump relay, I still turn on key and do not hear pumps running, I can only run the pumps by jumping the terminals. Does anybody have any ideas? Thank you in advance for any advice

Listening for the fuel pumps when you first turn on the ignition is not a fool proof test of pump performance. The pump relay requires a negative signal (ground) from the ignition control unit to actuate and run the pumps. You may ot may not get this signal every time you turn on the switch. The ICU receives a signal from the distributor (as it rotates) which allows it to provide a ground signal to the fuel pump relay. I suppose that this is a safety feature to prevent the pumps from running if there is no ignition. The ICU sometimes receives a false signal when you turn the switch on depending upon distributor position and other stored voltage in the ICU, hence the pumps will run momentarily. The best test is to remove the cover to the relay and see if it actuates when you are cranking the car. Place a test light on the yellow/red terminal, this is the output to the pumps. If the light comes on, you have power to the pumps.

Is it possible to bypass the green/blue wire from the pump relay and ground it to the firewall and not damage the control unit? I'm trying to determine why I don't have power going to the pumps through the relay, have new relay, when I jump the terminals the pumps run. When the test light is applied to the green/blue wire at the relay the pumps run w/key on, I showing no power at the yellow/red wire when key is on or off.

Thanks HB, I placed the test light on the yellow/red terminal, with key on and have nothing. However, I also put the test light on the blue/green wire with key on and the pumps started running, the test light was dim. I noticed on the schematic in the Haynes manual for 2.0 LH Jetronic system it says this wire is a ground that goes to the control unit? I'm not sure what that's telling me (if anything), bad control unit? Thanks again for your help

If your car is like my 93, that wire is the ground signal to the ECU. The ECU completes the ground signal to the relay when it gets a tach signal from the coil, telling it the engine is cranking/running. A common problem w/ the 561 ECU is a failure in this circuit. A common solution (although not one I'd do) is to splice into this wire and ground it to the firewall. The pump will then run whenever the key is on. If you get into a head-on, however, the pump will continue to run. Not a good thing if the fuel line is cut. I do not know if this is the same circuit that activates the fuel pump (at least in my car) for a few seconds every time the key is turned on. Look at a schematic and trace all the wires from the relay to the ECU.

Thanks again for all the info, another question I have, I started the car with the jumper wire in place (enable the pump to run), the car runs fine at an idle however it is sputtering still at the higher speed, it was sputtering when I started all this and I originally suspected in tank pump, but then it wouldn't run at all and the main pump wasn't running when I turned on the key.....etc. So now I'm wondering, does anyone know, if that JET-TRONIC controller goes south, does it send power seperately to the in-tank pump and the main pump? Perhaps my in-tank pump is bad? I was under the impression that when the key is turned to on that I should hear the main pump, but I've heard otherwise also?

On your 83 the Ignition control module sends the ground signal to the fuel pump relay. The ICU must receive a signal from the hall sensor in the distributor before it will power up the relay. Since you jumpered the relay and the pumps run (although the engine won't run properly) the problem must be in the distributor or the ICU. The only source of power to the fuel pumps travels thru the relay. You may want to check the wiring from the distributor to the ICU. Also clean the connector at the ICU.

Thanks again HB, I took the car to a local service place last Thursday, today they are telling me that both fuel pumps are toast, I asked about the ICU and the distributor and they assured me that they checked out ok. The car basically ran fine, then one afternoon running an errand it hiccupped a couple times, initially I figured just a miss something I could diagnose later. On my way home from the errand the car is acting like it's starving of fuel and barely runs at 2500 rpms the rest of the way home (6 mi), I replaced the fuel filter first, I started the car back up and it only ran for 30 seconds and then died, when I jumped the relay I got it started although had no acceleration. I never could pick up the in-tank pump running when I jumped the relay. Is it possible the in tank pump went south first, and then over taxed the main pump?
I think I need to talk to the mechanic personally and explain the tests I've done.