Volvo 740 failing to start

Hi, I'm new to this forum.

We are living in England and have a petrol Volvo 740 Estate automatic.

Recently it's been reluctant to start on cold days. Our initial thought was ice in the fuel so we added something to dry out any water in the fuel. The engine was turning over fine but failing to start.

This week the problem has begun happening when the car is warm as well as cold.

We were able to drive into town 2 days ago, parked for 10 minutes, then the car failed to start with a warm engine. The breakdown chap said it wasn't an ignition problem as it was turning over fine. However he gave us a boost that did enable the car to start. He said everything pointed to fuel pump relay.

We later changed the fuel pump relay on Monday as this is apparently a common fault in Volvos. It then began starting intermidently and would start on the second attempt. This morning again it failed to start. Each time we try to start it we hear the in-tank fuel pump doing its thing so I don't think it's that. Incidentally we took the case off the old relay and couldn't see any cracks.

It feels very much like a problem to do with not enough fuel getting through to initially start the car.

I have to stress that once we finally get the thing started it runs very nicely and doesn't stall or misfire at all. This must surely rule out lots of common problems.

Any advice, or anyone had anything similar? We have 6 children (one of whom is a baby) and really rely on the car on a day to day basis for transport.

Yvonne

We are living in England and have a petrol Volvo 740 Estate automatic.

Recently it's been reluctant to start on cold days. Our initial thought was ice in the fuel so we added something to dry out any water in the fuel. The engine was turning over fine but failing to start.

This week the problem has begun happening when the car is warm as well as cold.

We were able to drive into town 2 days ago, parked for 10 minutes, then the car failed to start with a warm engine. The breakdown chap said it wasn't an ignition problem as it was turning over fine. However he gave us a boost that did enable the car to start. He said everything pointed to fuel pump relay.

We later changed the fuel pump relay on Monday as this is apparently a common fault in Volvos. It then began starting intermidently and would start on the second attempt. This morning again it failed to start. Each time we try to start it we hear the in-tank fuel pump doing its thing so I don't think it's that. Incidentally we took the case off the old relay and couldn't see any cracks.

It feels very much like a problem to do with not enough fuel getting through to initially start the car.

I have to stress that once we finally get the thing started it runs very nicely and doesn't stall or misfire at all. This must surely rule out lots of common problems.

Any advice, or anyone had anything similar? We have 6 children (one of whom is a baby) and really rely on the car on a day to day basis for transport.

Yvonne

I agree that the original problem has all the characteristics of a bad fuel pump relay. Glad you changed it.

The starting on the second try raises the likelihood that the fuel pressure in the injector rail is bleeding off. The usual way to diagnose that (other than putting a fuel pressure guage on the rail) is to use a different starting technique. Try this: "bump" the starter (crank for a fraction of a second), let the key back into the "run" position for a couple seconds, then try starting. If it starts reliably that way, the pressure is probably bleeding off... usually back through the check valve on the output of the main fuel pump under the car beneath the left front seat. Mine has been doing that for years and I just use the bump/start method. That's how lazy I've become.

There is a related possibility. One of the fuel injectors may be dripping into the intake, which floods one cylinder and causes the others to have the symptoms above.

In either case, a bottle of fuel injector cleaner (as opposed to the fuel drying additive) is cheap, easy, and can't hurt. It may fix either problem by the time the tank of fuel is used up. If not, you're out a couple of pounds.

I have no idea why it is so hard to start an engine that has lost pressure in the fuel rail, but maybe the injection computer gets confused and tries a leaner mixture about the time the pressure comes up.

Mike

Hi, I'm new to this forum.

We are living in England and have a petrol Volvo 740 Estate automatic.

Recently it's been reluctant to start on cold days. Our initial thought was ice in the fuel so we added something to dry out any water in the fuel. The engine was turning over fine but failing to start.

This week the problem has begun happening when the car is warm as well as cold.

We were able to drive into town 2 days ago, parked for 10 minutes, then the car failed to start with a warm engine. The breakdown chap said it wasn't an ignition problem as it was turning over fine. However he gave us a boost that did enable the car to start. He said everything pointed to fuel pump relay.

We later changed the fuel pump relay on Monday as this is apparently a common fault in Volvos. It then began starting intermidently and would start on the second attempt. This morning again it failed to start. Each time we try to start it we hear the in-tank fuel pump doing its thing so I don't think it's that. Incidentally we took the case off the old relay and couldn't see any cracks.

It feels very much like a problem to do with not enough fuel getting through to initially start the car.

I have to stress that once we finally get the thing started it runs very nicely and doesn't stall or misfire at all. This must surely rule out lots of common problems.

Any advice, or anyone had anything similar? We have 6 children (one of whom is a baby) and really rely on the car on a day to day basis for transport.

Yvonne

Thanks very much for your helpful posting, and the other two people who posted too.

The problem turned out being water in the fuel which on cold days had turned to ice. The local garage removed a lot of water from the bottom of the tank and from the fuel injector rail.

Having had a couple of cold days where the car has started we're now fairly convinced that was the problem.

Looks like we could do with new spark plugs and distributor cap anyhow.

Thanks again for your reply to my original.

Yvonne

Aha water in the fuel good it turned out well Regards Nightmare "Yvonne and Dan" skrev i meddelandet news:Y%Qlf.24458$ snipped-for-privacy@newsfe6-win.ntli.net...