Hello, My 240 Died on the freeway the other day, acting like it was out of gas. I did some troubleshooting and the fuel pump will not turn on without bypassing the relay at the fuse panel. I have since replaced the relay with a BWD replacement, but it still will not turn on.

I have probed the wire on the relay leading to the pump with a voltameter, and it does not register any power whatsoever. Any thoughts on what to check next?

Any help is appreciated,
Thanks

 

I think it's my ECU. Grounded the Fuel Pump Relay as described in another thread, and the fuel pump started right up like it's supposed to. The car, however, still will not start. Going to pick up a used ECU tomorrow and see if that fixes it.

 

Are you saying that you jumpered the fuses, the pump started to run, but the car wouldn't start with the pump running? Then I would check for spark next, and make sure the cam turns while cranking by looking through the oil fill cap (timing belt check).

 

Yes exactly. It has spark though... i squirted a little starting fluid in it and it fired right up... for a second or two... which makes me believe that it's part of the fuel injection system, right?

Done so far:
Replaced New Fuel Pump Relay
Replaced ECU with one from a wrecking yard
Checked Fuel Pump (good)
Checked Air Mass Meter (Bad - have tried starting both plugged in and out)

Not Checked:
Oxygen Sensor
Coolant Temperature Sensor
Injectors

Also, The fuel pump does not come on when i turn the ignition on, unless i ground the ground wire.

 

Have since checked the Coolant Temperature Sensor and compared the reading to a chart i found on autozone. Ambient Temperature is 95 deg. and it tested at 1510 ohms. According to the chart, it's in the right area...

 

Test the continuity of your wiring, especially the circuit you grounded when you got the car to start. I'm assuming you got the advice to ground the fuel pump relay from a reply in a thread I made about my car when it was having a similar problem. I turned out to be my ECU. I'm guessing since you replaced the ECU and the relay that it's your wiring harness.

 

Are you grounding the blue-green wire on the FP relay?

Attached is the LH2.2 diagram. With the key on make sure ECU has battery voltage on pin #18, red-black.

Pin #1 should have some voltage on it while cranking.

It would be nice to know if the injectors are opening, using a noid light or by measuring the voltage to one of the injector plugs.

 

I Tested the continuity of pins 5, 11, 19, and 25 for grounds, and all tested good. Yea i think it was your thread. I did replace the computer, but it was a used one from a wrecking yard, so i'm not sure if it's good or not. It's doing the same exact thing the old one was though.

Yes i did ground the blue green wire on the FPR, and the pump runs like a champ when it's grounded, or bypassed... but not at all any other time.

I tested pins #1 and #18 for voltage as described, and they both had power.

I was going to test the injectors with a test light by rolling back the rubber boot and hooking it up, however, i cannot find my test light... i tested it with my multimeter though, and at no point during cranking did the tester show any signs of getting power. It stayed at 0.00v the entire time.

Out of curiousity, what does pin #1 control?

 

Yeah I guess thats right, you would need the jumper installed to see any voltage on the injectors because they are tied to the pumps.

Pin #1 is the ignition pulses from the ignition ECU - the pumps won't turn on until the pulses are present.

My guess is the ECU is still bad ....

 

Swap a known good distributor into the car. It sounds like your hall effect sensor went bad. It's in the distributor. Mine went bad and but I could jump the fuel pumps and hear them run, but it still wouldn't start. The ignition computer isn't telling the Fuel injection computer to wake up. So the FI computer acts like it's dead. You may also want to check if you got a newer or aftermarket wiring harness on the car. Pre-88 models have a tendency for the engine wiring harness to degrade. Check this page out for more info on that http://www.davebarton.com/volvoharnesses.html. Good luck!

 

Just replaced the distributor as joe suggested, and it started right up and runs great. It even fixed the hesitation problem i've been having the last couple months. Thanks a lot for all of your guys help, i really appreciate it!