I can not find a fuel pump relay on my father's Volvo 940. According to the followingpicture, it is the left one white relay.I reality there is empty spot on the relay tray. But car ran OK till last week, when it showed problem related to the relay.Can somebody help me find it or provide propperdiagram. Thanks

 

I don't know what else to tell you because that IS where the fuel pump relay is![sm=insomnia.gif]

~jon

 

My point is that the relay could not vanish from that spot, besides the car starts sometime. So, this picture does not relate to Volvo 940 '94 and the ralay should be somewhere else. I found in Related Thread the third entry following phrase 'You should have a small black relay behind the Ashtray. But the main relay for the fuel pump is under the hood. It is a big black relay with 4 wires going to it.' But I did not find 'the main relay for the fuel pump is under the hood'. If somebody knows where it is, please, advise.

 

Unfortunately that picture does relate to the '94 940, most years of the 740 and all of the 940 model years.

That is not strictly correct. The relay mentioned is theRadio Interference Suppression Relay which is mounted on the right side of the engine bay near the shock tower, unless it is a turbo model then it is fitted on the left side of the engine bay near the shock tower. It has four wires to it: red/black; 2 x red and red/green. This was fitted to stop the injectors interfering with the radio. The red/green wire goes to the injectors. If this relay has stopped working you will get no power supply to the injectors causing the fuel system to stop.

What has happened to the relay in the relay/fuse box I do not know, but the position shown on the picture is where it should be.

 

Thanks a lot. I am going to check my father's car this Sat. Will inform about result.

 

I finally checked the relay. It works ok. After checking ignition system and missing sparks found that primary coil's resistance was 0 ohm, input voltage - 0v in the moment of starting up the emgine. A missing 12 v appeared right after disconnecting on of two wires comming to the coil's terminals. Please advise whether I should change the coil and if so, when I can get it (a local Pep Boys shop did not have it even in their computer system). Thanks.

 

Autozonewillhave it.

 

Thanks a lot. They really had the coil.

 

Bought the coil today. First of all checked resistance on it and found exactly the same 0.8 ohm as on my Volvo's coil. But any way checked on the car. Of course, it's doing the same - no sparks. Since input voltage is supposed to be interrupted by transistors circuitry and I have just 0.3 v on the coil's terminals, maybe, that circuitry does not work well? Anybody had something similar? I also started to think about timing belt. But my father replaced it about 3-4 years ago and drove at most 3-4 thousands miles. Any suggestions?

 

Sorry for bringing this thread back from the dead but I just purchased a 1994 Volvo 940 wagon and am having the intermittent starting problems and it died on me the other day. So I checked behind the ash tray and I too am missing the white fuel pump relay. Just an empty spot. The car drove home for an hour on the highway no problems, then died later in the day. Then died again the other day. If this were the fuel pump relay, shouldn't the pump not be working at all, or is it possible the primary pump is working but not the secondary? Any help on this would be very much appreciated.

 

940's flat won't run without that relay, its actually a double relay and powers the fuel injection computer with one half, and the fuel pumps with the other half.

And, its in the same position "E", relay 2/13, on *all* 940s, from the earliest to 1995, the only car thats different is the 1991-only "940SE" which is really a 760/960 turbo.

so... if the car is running without that relay, I can only guess that someone rewired it differently.

 

Thanks, looks like I'll be pulling the fuse panel to trace some wires.

 

Same issue. 1993 Volvo 940. Starts periodically, runs for a bit then doesn't start. Changed fuel filter. Topped up fuel. Went to look for relay switch and it is NOT where it should be. Trying to decide if the pump is fubar.
I've seen this issue in a number of forums and haven't seen a solution.
Thanks for any input.

 

some late 94/95's do NOT have the standard fuel dual relay, instead they redid it, this is described elsewhere.

is your 93 Bosch or Regina?

 

Not sure yet.

 

Bosch EFI cars have a MAF/AMM (Mass Air Flow aka Air Mass Meter) in the intake plumbing, this says BOSCH on top and is pretty distinctive. Regina instead has a much smaller "MAP" (Manifold Air Pressure) sensor stuck in the side of the air pipe.

Bosch ignition systems use a standard 'soda can' style cylindrical ignition coil, while Regina/Rex ignition systems use a square 'transformer' style ignition coil.

I've heard of bastard cars that had Regina injection with Bosch Ignition but thats fairly uncommon (Volvo's can a bit of a 'parts bin' car sometimes).

anyways, there's a whole bunch of possible causes for a car to stall when it warms up and be hard to start again until it gets cold. It can be from fuel injection or ignition (spark) problems, and tracking the actual cause down will require some diagnostic skills, rather than just throwing random parts at it and hoping that fixes things.