Hi folks,

I've got an 89 240 sedan. A few years ago, my brother was pulling out of a parking spot and it sputtered and died and hasn't started since. I've finally gotten around to working on it. I went ahead and replaced both pumps, the tank itself (had a pretty big rust spot on the top where gas was leaking out), the fuel send unit, and the fuel pump relay on the passenger side.

When I try to start it, it turns over but won't start. It's sparking, so no fuel to the engine. I can short fuse 4 to fuse 6 and I can hear the in-line fuel pump run, but when I turn it over, it still won't start. I'm not sure how to diagnose any further. Anyone have any ideas?

 

Check the radio suppression relay. It provides power to the fuel injectors.
Dave's Volvo Page - Volvo Relays

 

No radio suppression relay on the 240. General list of things to check:

1) Is the cam shaft turning? Open the oil cap and shine a light in there while a buddy cranks the engine. If the cam shaft doesn't turn then you have a broken timing belt.

2) Check the 25 amp blade fuse on the driver's side inner fender near the battery. It provides the power to the fuel injection system. The position of this fuse makes it a good spot for moisture to penetrate and cause corrosion.

3) You replaced the fuel pumps but are they running properly? Check out procedure for the fuel pump system is here:

In the Tank - 240 Volvo Tank Pump and Sender

4) Check your crank position sensor. It provides the timing information for both the fuel injection and the ignition system. It is located on the top of the bell housing where the engine and transmission meet. It has a black coax cable that runs to a connector on the firewall. If the insulation is cracked and flaking, then it needs replacement.

 

first thing I'd do is try starter fluid... shoot a healthy shot into the throttle body and crank it over. if it fires up and runs for a second, then yes, you have good spark on time, and no fuel delivery, so its time to further investigate the fuel system.

note, that CPS provides not only the fuel injection timing but also the spark timing, so no CPS == no spark.

 

Camshaft is turning.

Checked the resistance between the connectors with the fuse in, and it was well under a fraction of an Ohm.

Shorted the left side of fuse #4 to the left side of fuse #6 (12 V from the battery) and heard the in-line pump run. Shorted the right ride of fuse #4 and heard the tank pump run. Solid indicator that they should be working (although there is a chance I wired them incorrectly, although I don't hear them run at all when I crank the engine over).

I can see the sensor, the cable is in pretty good condition, but I might as well and replace the sensor itself to be sure. Is there a way I can test the sensor itself with a multimeter? Or would I need an oscilloscope for that?

I've heard some things about the possibility of it being an ECU issue (specifically with the so-called "pink label" ECUs, which I have on this car). Would those be valid concerns or just wild speculation?

 

Well, I definitely have a spark. I pulled out a plug and turned the engine over and I could definitely see it sparking. Although I don't know if that's a definitive test on whether the timing of the spark is correct. I will try the starter fluid method in a little bit.

 

Okay, just tested the CPS. I was reading between 0.1 and 0.2 volts when I was cranking it over, so seems like the sensor is okay (tested as per instructions in this thread).

 

Pink label ECU could very well be the culprit. The failure on these ECUs is with the fuel circuit. When you performed the jumper test, did you try starting the engine with them jumpered? If it runs with the pumps jumpered, then it is either the ECU or the fuel pump relay.

When you turn the key to the II position, do you hear the pumps run for a second and then shut off? If you can hear them run but it still won't start, then it is doubtful that the problem is with the ECU or the fuel pump relay.

If you don't hear the pumps when you turn the key to the II position, then first check the fuel pump relay. Typically they develop cracks in the solder joints on the little circuit board in the relay. You can re-flow the solder on them rejuvenate the relay. Try that first. If that still fails to get the pump running when the key is in the II position, then more than likely it is the ECU.

 

I didn't even think to do that. I'll give that a shot and see what happens.

The pumps do not run when I turn the key to the II position.

The fuel pump relay was replaced by a Swedish Pro Parts unit not long after the car stopped working, so likely the ECU? Are there connections to the ECU I can jump to potentially bypass it for the fuel system?

Thanks for all the help.

 

doing the fuse jumper thing with the fuse left in place (so both pumps run) effectively bypasses the ECU and fuel pump relay. if it starts and runs this way, you either got a bum fuel pump relay, or a bad ECU.

 

 

If it doesn't start with both pumps running, I wouldn't jump on the ECU. A failed ECU would keep the pumps from running.

You say the car sat for a while. When you replaced the main pump, did you replace the filter? Any gunk from the tank will get caught in the filter and may clog it.

If it were me, I would do some diagnosis first. Check to see if you are getting pulses at the injectors. I have in the past used an LED with a 680 ohm resistor across the injector to see pulses. You need to make sure that the polarity is correct for the LED to light. Just try it one way and then the other. If you don't get pulses at the injector then it won't start and I would diagnose from there.

If you are getting pulses, you might want to verify the fuel pressure at the rail. You need a tester for this and may have to adapt some fittings. The tester can be borrowed from and Autozone or Oreillys.

 

That is what is happening right now. The fuel pumps do not run unless I jump them, so something is preventing them from running. But even when they are running, the car still does not start, so perhaps I had wired them backwards with the polarity reversed or something. Who knows lol.

Yes, I replaced the filter too.

I will try those both out and see what happens. I will need to find out where I can buy a resistor. I don't happen to have any around the house, and now that RadioShack is essentially a goner, not sure anywhere else that would carry them.

Thanks for the help!

 

Okay, I tried jumping the fuel pumps with the fuel line disconnected (so the pumps just pump right out into the open, into a small tupperware I had underneath). I tried both pumps separately, and gasoline poured out of the line, so I definitely wired them up correctly.

I'm going to move onto the injectors next. Is there a way I could test the injectors without an LED, like perhaps with a small 12 Volt light bulb?

Update:
Okay, fuel is definitely making it to the rail. I haven't tested with a gauge, but I can definitely hear the fuel moving through the fuel pressure regulator to the return line.

I tried taking the connectors off the injectors and measuring the voltage across them while having a buddy turn the engine over. But I didn't see anything on the multimeter. But I'm not so sure that's a definite test, since the sample rate of my ****ty harbor freight multimeter is pretty low.

I'm going to hedge my bets that it's the ECU that crapped out, unless anyone has any other ideas. I popped the interior panel near the passenger side feet, and got the part number of the ECU. Its a 0280000561 pink label ECU, which I have heard craps out frequently. I tried performing the on board diagnostics test with that little LED-and-a-button-thing in the engine bay near the driver side upper strut mount. I plugged the little probe in port 6 (ignition) and held the button down for a second, and got 1-1-1. Tried the same thing in port 2 (fuel) and got no code at all, just a dimly lit LED (but not as dimly lit as port 6).

 

there's a test accessory called a 'noid light' (no idea why they call them that), you unplug an injector, plug in the noid light, then plug the injector wire into the noid light, then crank the car and the noid light should pulse with the cranking.

 

One test you can perform with your multi-meter is to take the black lead and connect it to a good ground source (negative post on the battery would be best). Turn the key to the II position and using the red lead of your multi-meter, check the voltage at both sides of the injector connector. One should be at or close to 12v. If that is the case, then the injection system has power. The ECU grounds the other side of the injector to make it fire.

If the pumps don't run for a second when the key is moved to the II position, then it may be your ECU or it could be a failed fuel pump relay. A failure on either one of these two items could cause the pumps not to run and the relay is a common point of failure on these cars. For me, I try to verify the most likely items first. I have a pink label ECU from my old wagon that lasted 20+ years without a failure yet I had to fix the fuel pump relay twice in that timeframe. If you have a soldering iron - the relay is an easy thing to eliminate in your troubleshooting just by resoldering the solder joints in the relay.

Getting fuel to the rail may not be enough as the pressure has to be correct for the injectors to deliver the right amount of fuel. Definitive test is to use the pressure gauge.

 

 

 

 

Okay, new issue has manifested over the weekend that I think is fuel related. The car has a great difficulty starting now. When I turn the key, the engine turns over and I have to give it a little gas for it to start. Otherwise, it will just crank and crank and crank and never start. When I turn the key to position II, I hear the fuel relay click and the pumps prime the engine for a second. When I am on the highway, I can't go any faster than 60-65, because when I push the pedal any further in, the engine won't put out any power and the car begins to decelerate. I'm thinking that either the fuel pressure is too low (I suspect the main pump, as it was a rather cheap aftermarket unit), or perhaps part of the air intake or something has come loose. Any ideas?