Hi all,

As the title states, i have a 1987 Volvo 740GL. Due to the age of the car, the fuel feed line that goes from the fuel filter (with the banjo bolt), into the fuel rail in the engine, has started to lose its vacuum sealing capability. As a result, on a cold start it is quite hard to start the car first time due to the absence of pressure in the fuel system. My Volvo mechanic has been able to diagnose the hard starting issue to this particular hose, but noted how he was not able to find a part number for it. I would greatly appreciate if anyone would let me know the part number?

This picture is a good representation of what i'm looking for. The hose in the picture is the one titled 'To Engine'. https://www.justanswer.com/uploads/a...5_42365658.gif

Thank you.

 

vacuum sealing?? that main fuel line is under 40 or so PSI of pressure, if its leaking, fuel would be spraying out all over, ka-WHUMP, your car would burn to the ground.

the main fuel line from the filter to the fuel rai is, I believe, 1342033, but I seriously doubt that is available any more, more likely you'll need to fabricate something, perhaps using copper-nickle brake line, and suitable metric banjo fitting at the fuel pump, and a flare fitting at the fuel rail.

lack of fuel pressure at start is more likely to be the 'non-return valve' on the output of the fuel pump, 1326899... thats part #2 on this drawing... (the fuel line above is #18)
https://www.volvopartswebstore.com/s...roduct=1114719

(all of this is for a non-turbo 1987 740).

 

Thanks for that info.

Perhaps i might have worded it incorrectly; the line may not necessarily be losing its vacuum, hence nothing is actually leaking. But this is what my mechanic suggested should be replaced due to the harsh cold start because of lack of fuel pressure when the engine is cold. He has encountered other 740s with the same issue, so his bet is on the main fuel line. In regard to the non-return valve that you mention, could this also be the cause of a very hard cold start? In the morning when i try to start it, starting it first try is almost impossible. The car would crank as usual, then it starts up but idles anywhere from 200 - 400 rpm and fluctuates up and down. Then, proceeds to stall. When i go to start it the 2nd time straight after, it starts up after 2 cranks - no problems. When the engine is warm, it starts up like new. So the issue is always on a cold start. It has a 2 year old distributor, leads, and spark plugs. There are no vacuum leaks, the fuel pump works well, and i just fitted a new fuel filter. This issue has only started to occur to me about 1 month ago. Prior to that, i have never had a single problem with a cold start.

My mechanic managed to narrow the issue down to fuel pressure. The fuel pressure regulator, injectors etc. are all perfectly working too - so that wouldn't be the issue.

Any suggestions?

 

Greetings its Goldenblock here!! The answer is its your main fuel pump check valve!
its the metal piece that attaches to your main fuel pump which connects to the main fuel line to filter piece! It is either lost its ability to hold pressure or the internal component is missing!
not the fuel line its your check valve my friend!!
Osss

 

the check valve is actually between the main fuel pump and the filter, as shown by #2 on the diagram I posted above.

 

the test for this check aka non-return valve is to hook up a fuel pressure gauge to the main fuel rail, and run the pumps, you should see the proper fuel pressure (42-44 PSI minus the manifold vacuum of 0-9 PSI). now switch the fuel pumps off. the pressure should hold for several minutes at least if the check valve is good. if the pressure drops immediately, the check valve is bad.

 

OK thanks for that.

I can get the non-return valve for $30, so i will replace that. Hopefully that fixes the hard cold start.

 

Your welcome im happy to help you diagnose and save you money! See my ad on Atlanta craigslist type in volvo parts or redblock heaven!!!
Osss