OK guys, I am not a Volvo Owner. However, my neighbor has a 1986 Volvo 740 he bought new from the factory when he was stationed over there. I know the car has been sitting for 3 years. He said prior to that, he had th in tank fuel pump replaced. Drove home fine, came out to start it later and it would not start. He said he tried a few more times and it started once. After that it would not start.

Yesterday I messed with it. It will turn over with no problems, but will not start. I checked all the plugs and coil and they all have spark. I also sprayed a little WD40 to see if I could get it to fire, but nothing. I plan on trying some starter fluid today. While checking this forum, it appears that there is a fuel pump fuse under the hood by the coil? Also, I am thinking fuel pump relay? Last thing, I was looking under the car and noticed by that there are 2 canisters tht the fuel line runs to from the fuel rail. I assume one is a filter, what is the other? They are under the drivers seat.

 

Also, is there a way to check the fuel pressure?

 

Not sure about how to check the fuel pressure but that bracket under the car has the fuel filter and the main fuel pump. Maybe it's out. I'm pretty sure the fuel pump relay is under the dash behind the glove box.

 

Your car has 2 pumps,one below and one in the tank as has been mentioned.The one below is the main pump while the in tank one is the help pump and is secondary. But I think your problem is the fuelpump relay. Almost sure its burnt off because the previous owner had fuelpump problems. Its usually found behind the radio if you take out the ashtray you will see it.Its big and white in colour but in some older car models of the 740 they were green I think.

 

Thank you for the replies. It is definately fuel related as it started with some starting fluid (just a little spray) I will look behind the ashtray with the fuses as I didnt see it under the dash behind the glove box.

 

Ok, found the big white relay....cant miss it once you know where to look. Anyways, tested the relay and it checks out fine....So I am moving on to the fuel pump and filter...

 

on a 740, the fuel pump/fuel injection relay shoudl be in the main relay panel, its only under the glovebox on a 240.

to test the fuel pressure, you need a fuel pressure gauge, with euro specific adapters, you disconnect the main fuel line where it attaches to the fuel rail, and install the fuel pressure gauge inline (the adapters are like a T), then you have to turn the engine over or manually jumper the fuel pump relay as the pump only runs about 1 second when the key is turned on, then shuts off til the car turns over.... fuel pressure should be between 42 and 44 PSI with no manifold vacuum (its 42-44 PSI above manifold vacuum, so if the vacuum is -7 or so at idle, it would be 37psi or so...)

 

If the intank was new and replaced then the one below is out. Try filling upp the car with gas so its a full tank and if it starts now then the pump below is out.Thats the easiest way to check. Car can start with more than half full tank but less than half then it does not start.

 

the bit about starting with a full tank applies if the in-tank pump is dead, but if the main pump (under the car) is dead, it won't run at all any which way.

jack up the back right side of the car, stick your head under there while a friend turns the key on/off without trying to start. each time he turns it on, you should hear the pump run for about a second, a soft 'whirr' sound. if the gas tank is half or more empty, take off the gas cap, put your ear near it, and same thing, key on (wait a coulpe seconds) key off, repeat, and you should hear the in tank pump whirr.

 

btw, if that car has been sitting for years, whatever is in the gas tank is only useful as paint cleaner.

I'd siphon out most of it and put in at least 5 gallons of fresh gas. you can burn off what you removed a couple gallons at a time in a full tank of fresh gas after you get stuff sorted out.

 

Ok, got it running.. The fuel pump and filter were both bad and the wiring was shot. Now, when it runs, the RPMs are at 3k and wont idle down. It looks to have an electric choke mounted on the rear of the throttle body, but nothing plugged in and I can not find the plug. So, what do you think is going on with it? Maybe the MAF is bad?

 

only thing plugged into the throttle body is the idle switch, that tells the ECU the throttle is closed so the ECU can regulate the idle