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1990 Volvo 240 No Fuel Problem

staceyz

New member
Joined
Sep 29, 2012
My 1990 wagon will run when I use an alligator clip from fuse #4 to #6. I can hear the main pump run and the car will fire up and run. I'm in the process of replacing the in tank pump as it is dead. But I don't think that is the problem, if it runs on the main pump with the jump at the fuse panel. I also read you can pull the Fuel pump relay, and insert a wire made with 2 blade terminals into the socket from Red #30 to the Yellow/Red wire. This also makes the main pump run, but the car won't start in this position. I've bought 2 new $25 Fuel Pump Relays, and wonder if they are a bad batch, as when I open up the relay, I can see cracked solder joints! I reflowed them. I also ordered a new Volvo fuel pump relay for $75 so we'll see... any ideas?
 
Joined
Dec 1, 2021
fuse 4 get supply from Relay and passes it to in tank.
Fuse 6 gets supply from main battery and sends to relay which allows flow to Main pump and in tank (via fuse 4).

So jumpering with car on provides power to pin 87 on the relay and that feeds main pump, and also gets power to in tank.

Pin 30 and Y/R (87) does run the pumps, but skips pin 87b which provides supply to control pressure regulator and aux air valve (these may also be partially fed by the right side of relay 4), but if those aren't getting supplied properly (like fuse 4 removed at time of testing) then those may not perform properly.
-->Try doing #30 to 87 (Y/R) and 87b (BL).

Doesn't directly explain why fuse jumper works since you'd still be skipping 87b, unless on the relay 87b works but 87 doesn't. Try sticking a multimeter probe into the back of the connector for 87 and 87b and key on, see what voltages you get. (also compare to key off)
 

cleanflametrap

Active member
Joined
Sep 3, 2009
Location
near baltimore
Does your fuel control unit (behind right side kickpanel in North America) look like this?

lh24_1813.jpg


If so, find one with the updated hardware and a white label like this:

lh24_1945.jpg


Or even this:

lh24_2011.jpg


A cheap test lamp to 86/2 terminal of the relay socket will confirm it is the ECU at fault. Be very careful putting jumpers in the relay socket; some folks have destroyed their good white label ECUs with one mistake.

There are other safe alternatives too. Google "volvo pink label" or search this forum for same.
 

staceyz

New member
Joined
Sep 29, 2012
Thank you for the replys, I will check with a multimeter at the plug for the Fuel Pump Relay. Good tips...

I also got rid of the pink ECU as soon as I got the car, even though it worked fine, and got a white label one. I just heard bad things about the pink ones..

One question about testing the 86/2 Socket on the Fuel Pump Relay for ECU.., should I turn the key on to test..?
 

cleanflametrap

Active member
Joined
Sep 3, 2009
Location
near baltimore
One question about testing the 86/2 Socket on the Fuel Pump Relay for ECU.., should I turn the key on to test..?

If you probe 86/2 (the one with the blue/green wire) as you turn the key on, expect a one-second low voltage and then remain near battery. While cranking, expect it to go low again, when a working ECU detects the ignition pulses and engages the fuel pump relay.

If, while you are running the engine with the fuse 4-to-6 cheater in place, you see battery voltage on 86/2, suspect the ECU or the wiring to its pin 20 is damaged.

lh2.4relay.jpg
 

staceyz

New member
Joined
Sep 29, 2012
Thanks so much for the very precise answer. I am awaiting a couple parts in the mail to finish the in tank pump assembly, as everything is apart...then will do the tests.
 

apachechef

Burnt Sierra Madre
Joined
Jan 26, 2009
Location
An obscure body in the SK system
Thanks so much for the very precise answer. I am awaiting a couple parts in the mail to finish the in tank pump assembly, as everything is apart...then will do the tests.

NOTE WELL

the in tank pumps can be wired backwards, VERIFY that pump is correct before reinstalling, see Art's awesome site for more info, Cleanflametrap.com
 

staceyz

New member
Joined
Sep 29, 2012
OK, I have both pumps working fine (in tank, and main pump) I put in a new Factory Volvo Fuel Pump Relay. Still doesn't run. I tested for power at #30 at pump relay and have 12.11 Volts. Car runs and starts with the fuse jumped from #4 to #6. While the car was running, I tested the Volts at the Fuel Pump Relay 86/2 (blue/green wire) and have bouncing volts from 2 to 12 to 8... etc. It may be my ECU..? One more check I will do, and let me know if this is correct, is to put a wire to Fuel Pump Relay 86/2 and then ground the other end, and see if the car starts. (this is should replicate what the ECU is supposed to do when it activates the relay.?)
 

staceyz

New member
Joined
Sep 29, 2012
I also double checked... and I do have a PINK Label ECU!!... I guess it was the previous car I replaced!!!! I'll see if anyone still have a good white label ECU!!!
 

dl242gt

The world of the smiling Dogo
Joined
Jun 21, 2002
Location
S NJ, a suburb of Phila.
Seems like it is the ECU not grounding the fuel pump relay to give you fuel. I'd try to get a 951 since they are a bit more developed than the 561 ECU. My cars have always run a bit better with the 951 installed.
 

staceyz

New member
Joined
Sep 29, 2012
Thanks everyone, I went and bought a used 951 ECU (Everyone around Vancouver BC wants $275 Cdn) I installed it and....... RUNS GREAT!!! I was just thinking, my 1990 Volvo 240 got 32 years with the PINK ECU, not too bad for a bad part!! All the best, and thanks again for the help!

Stacey (Vancouver, BC)
 

dl242gt

The world of the smiling Dogo
Joined
Jun 21, 2002
Location
S NJ, a suburb of Phila.
Glad you are rolling. Enjoy your ride. When the pink ecu failed in my mothers 1990 245. It just kept setting a 232 code over and over. It actually still ran the car fine. We put a 951 in that car as well. :cool:
 
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