'89-740 (8 valve) No Start

[Laird Scooby]

Originally Posted by TonyS9

1 or other of the 2 pumps should be working. Gravity feed would be enough to get main pump working but-

1. A small bore hose might cause the hose to collapse or the pump to cavitate, gravity feed in my 360 injection is 12mm (has a bottom outlet tank), 340 modifiers trying to pull fuel out the top of a tank from the 6mm outlet often have problems.
2. You need to prime the feed hose so it symphons the fuel from the jerry can, a pressure pump won't suck enough air to pull the fuel up out of the can.
3. If the pump is whining, it is usually working. It stops working because the brushes have worn out usually.

It seems to me your pressure pump test maybe flawed, and the lift pump in the tank is faulty. Disconnect the pressure pump power and listen for the lift pump working, and check it is definately getting power.

What Tony said ^^^^^ and more eloquently than i could have managed this morning!

[Volvoaus]

Originally Posted by TonyS9

1 or other of the 2 pumps should be working. Gravity feed would be enough to get main pump working but-

1. A small bore hose might cause the hose to collapse or the pump to cavitate, gravity feed in my 360 injection is 12mm (has a bottom outlet tank), 340 modifiers trying to pull fuel out the top of a tank from the 6mm outlet often have problems.
2. You need to prime the feed hose so it symphons the fuel from the jerry can, a pressure pump won't suck enough air to pull the fuel up out of the can.
3. If the pump is whining, it is usually working. It stops working because the brushes have worn out usually.

It seems to me your pressure pump test maybe flawed, and the lift pump in the tank is faulty. Disconnect the pressure pump power and listen for the lift pump working, and check it is definately getting power.

Thanks for reply TonyS9
1. & 2. - Also tried priming the main pump by jerry can 12mm hose connected to feed hose at fuel sender end (not blocked – you can blow air through it). Maybe hand held pump from jerry can I was using caused cavitation? Still no start

3. Main pump seems to work (whirring)
Have tried listening to in-tank pump working (I have tinnitus so hard to tell). I think my in-tank pump test was flawed (I tested max-min sender travel which was within spec). Will pursue this along with power to the unit
With gravity feed, will also disconnect outlet from main fuel pump see if any action there (have already tried inlet side with no success).

Getting a tow truck organised to get the 740 off the street and to my place

Process of elimination, after all this may proceed to fuel rail area. Is there a technique of cracking those two big nuts on fuel rail inlet if I need to go there?

[TonyS9]

It should come undone with an adjustable and a spanner, but check for a scrader valve on the manifold. 940 have this (also underneath), but 360s of the era as the 760 don't.

[Volvoaus]

Problem solved – thanks for all the input.

Turned out to be a dead in-tank fuel pump. A litany of errors along the way including:
1. Fuel tank only had about 10lt (about 2 gallons for all you imperial folk) which meant the main pump couldn’t draw enough juice
2. The Youtube inspired multimeter test I did on the ‘wreck’ (breaker) in-tank pump was flawed. Its better to connect 12v battery to the sample and test. Apparently the fuel pumps need petrol because it lubricates (I used diesel to test so there were no sudden explosions)

As an aside, the 740 is my son’s car. He is a carpentry apprentice and not in a position to stuff around. He has now purchased an Aussie tradie ute. Now to decide what to do with the car? It has absolutely no rust (credit to Volvo). It is beautiful to drive and as a Citroen GS man, I am very impressed with this Swedish beauty
I did manage to track and clean around 10 earths along the way. Including all the fuses

[Ian21401]

After all that work keep the Volvo especially as it’s rust free.

[Laird Scooby]

Originally Posted by Ian21401

After all that work keep the Volvo especially as it’s rust free.

It will be handy to have something reliable capable of swallowing huge loads when the ute goes belly-up or it starts snowing again.