Howdy to anyone. Looking for some insight here. I am a '78 245 DL and the other day I decided not to start for my dumb human forcing his lazy *** to ride his bike to the store. He is slightly perplexed to the issue and was hoping for some constructive input. As I am my human's first Volvo, this is a touch and go relationship and he isn't a wicked idiot and will usually stop before getting in over his head. He's fairly handy and mechanically savoy, but in some case (such as current) if it's not entirely obvious he'll do his diligence and research. So here we are.

My issue seems fuel related. I really want to to start, key turned over, all systems go... And no start. Chug-a-lug. Pump? Relay? Filter? To my understanding of my Chilton and Haynes my fuel pump is located in my tank? Accessible through the back, under the panel in front of the rear storage trunk? If this is the case, would it be possible to conduct a process of elimination as to avoid tearing into the tank, i.e. relay or something more simple? Or should we be proactive, and replace the pump, relay and filter ect. knowing this **** is likely OG or at least old enough to need replacing? What might be something to look/listen for to better pinpoint the problem? Suggestion and tips welcomed!

with love from a busted *** driveway
Mr.Pink

 

Your car has 2 fuel pumps. A feeder pump in the tank and the main fuel pump mounted under the car, under where the driver sits. The car will run with a bad feeder pump until the main pump dies from stress, but will not run with a good feeder pump and a bad main pump. The system needs about 65 psi fuel pressure to run properly. When running if the main pump is noisier than normal you probably have a bad feeder pump.

You should be able to hear the main fuel pump buzz when you first turn the key on or bump the starter. Both pumps come on to build pressure - then turn off if there is no spark present. So - open the door, if the key bell still works - push and turn the door switch to make it quiet. Bump the starter with the key and return key to on position - you should hear from under the car Buzzzzzz for about 1 second. You may have to get your ear closer than sitting upright in the drivers seat to hear it. That's your main pump. If not - could be bad or poor connection at the fuel pump fuse, bad or poor connection at the relay (green? 6 prong relay above drivers knees.

 

Oh, also Hoonk. Would you be suggesting that the feeder pump in the tank should be my last line of defense after eliminating main pump and electrical?

 

Update. It appears that the pump is working as you can hear it. Also checked the filter and there is gas w/pressure leaving the filter. Any suggestions from here?

 

basics:
Compression, spark, spark at the right time, condition of ignition cap/rotor/spark plugs/plug wires/, fuel pressure, control pressure, and rest pressure. Control and rest pressure is difficult to measure on that car without specialized fittings but you might be able to read fuel pressure by t-ing into the fuel line after the pump and before the fuel distributor. Quality and quantity of fuel (feeder pump hoses break - that's a short hose that connects the pump to the sending unit - if that breaks and the fuel level is 1/4 or below - the pump will suck air. )

 

Fuel distributor perhaps, but obviously not the easiest component to get to just to inspect. I did replace plugs (cause I had a set and it took like 5 minutes) You might be on to something with the feeder hose and sender unit. But that does put us back into the tank... I guess I could test that with a fill up. We are sitting pretty low. Does it mean anything if I mention the level gauge is seems to be not very reliable? It'll go from half to empty and back from up and down a hill. I understand how the mechanism works, but is it really that sensitive? Thank you for your input regardless