Hi Everyone.. this is my first post.. so thanks in advance for any and all advice. I own a 1991 Volvo 740 wagon with 125k miles that I bought used with 120k on it.

Recently I've experience the following problem.

My fuel pump doesn't always work so my car doesn't always start. Sometimes it starts and sometimes it doesn't and I haven't identified a pattern. When it doesn't start.. I just wait a while.. and then it does. It can be running fine and then I turn it off and it doesn't restart. I can be driving down the road and lose engine power.

When I hear the fuel pump (in the gas tank) the car starts. When I don't hear the fuel pump turn on the car doesn't start. (surprise surprise)

When I hold the Fuel pump relay (located behind the lighter socket) with my finger I always feel it click whether it starts or not. The date on the fuel pump relay switch indicates it's four years old.

My current thought is
A) either the pump is bad and turning on and off intermittently, or
B) I have a electrical problem.. either power or ground.

I've completely cleaned my battery terminals thinking that was the problem but that didn't help. I've also tried jiggling he electrical wires on the battery terminal but that doesn't seem to help.

so.. my questions..
1) how is the pump powered.. via the battery?
2) Can pumps fail intermittently? i.e. sometimes they run and other times they don't?
3) do Fuel relay pump switches fail intermittently? A fuel relay pump switch is a $41 part which I'd hate to replace if it's not broken particular if I have to budget for a fuel pump replacement
4) has anyone scene replacing a fuel pump in this model documented anywhere as a DIY job?
5) any other things I might consider checking.. either electrical or otherwise in terms of figuring out why the pump works sometimes and other times not.

Sure seems like a pain to get to the actual Fuel Pump.

Again.. thanks for the read and any suggestions in advance.

Anthony

hi, ive just had the same problem with my 940 turbo
1 check your fuel pump relay
2 could be a faulty ecu unit,its a common fault with this model this could be expensive so look on e bay , see part no this is on the unit make sure this matches
3 to by pass the ecu ive wired my fuel pump direct to the fuse box, i checked with Volvo and they say this is ok for a temp fix however the pump will be permanently running , the pump has an outlet for unwanted fuel to an overflow reseviour so you cannot flood

Hi, I had a similar problem with the fuel relay in France last year,on inspection of the relay after removing it's green plastic cover,I noticed that the printed circuit board was overheating on one of the pins, the solder had melted giving a dry joint and subsequent intermitant fault,cured mine in minutes with a soldering iron,I tend to carry a spare,must be quite common as this has happened on two previous occasions,worth a look,could save you loads of the hard earned cash,good luck :57:

i had the same problem on my 87-740.....first i replaced the fuel pump relay........it turns out that i needed a new fuel pump..car has been running like a chap ever since...be prepared to spend $500..there are 2 fuel pumps...the in tank one is about $150, the in line fuel pump is about $350


good luck!

Thanks folks - I replaced my fuel pump relay.. $40 at Napa (though If I'd know I could have gotten a 7% AAA discount. Napa refused to offer me the discount retroactively when I went to return the relay because that wasn't the problem. I think its the in tank pump. (it seems to be under duress when I listen to it. I actually banged on the tank with a rock and it seemed to sound better (and start)). Anyone have a handy link to a repair procedure to replace the in tank fuel pump on a 1991 volvo 740?

Thanks everyone for the replies. Regards, Anthony

I think I read somewhere that the in-tank fuel pump is crucial for fuel level in the tank below half; when the tank is full, it's malfunction should cause no special problems. Is this correct?

some 740's have only in- tank fuel pump.
Removal is hassle. Any help appreciated. URGENT!!

1991 740 Turbo

Sometimes when driving around town or on freeway, I experience a brief loss of power. Occurs every couple of weeks or so, not a constant issue. Sound more like a fuel filter, fuel pump relay, or fuel pump problem ?

740 in tank fuel pump removal - this is from my memory as i got bored one time and was interested in what a random metal plate was covering :)

Open the boot
open the bonnet - disconnect negative terminal.
lift carpet at the back fo the boot, and you will find a rectangular plate secured by 4 bolts
remove the bolts and the plate

you will see a round unit with a few wires and pipes, this is where the level sender and pump is located.

around this unit is a big screw cap, i think this undoes if you turn it clockwise ... not sure on that

thats how you remove it

be careful when you replace it though and dont knock the sender either as if it goes back in at a funny angle you get all sorts of funny fueling problems when you start to get near half way point in the tank and yout fuel tank meter will be way off!!

Matt

PS - this is the fuel tank your dealing with so please DO NOT smoke or do this with battery terminals connected or anything cos you will blow yourself up or something and i would hate to know that by not putting this warning and you did do it i could be atrributed to causing your immediate death.