XC90 D5 Cranking But Not Running - Injection Pump Issue

[zakmuh]

Hi,

I had to take high pressure diesel pump out of the way for a work in the engine. After putting it back engine cranks but wouldn't start. Called RAC....the guy used Easy Start sprayed through the intake and car started straight away and ran fine. He suspects it is the high pressure Injection pump faulty. I did disconnect the battery before starting the job. Checked all the fuses no luck ( there is no specific fuse for injector pump but for fuel pump), I did prime by loosening hose 4 but no luck again.

Please see attached pics for references:
When I did the priming, when key in position II fuel comes to inlet hose 4 and banjo bolt 3, and return hose 1 and hose 2. I don't know if this is how the pump works but...when key in position II should fuel come out of return line 1 (hose 1) as well? When cranking diesel would just flow a small amount through the outlet 5 - not jetting out as it should for injection.

No fault codes - no fuel pressure in fuel rail but fuel pressure sensor (No 9) or fuel flow control valve (No 13) are not throwing any codes!


Before buying a new pump I just want to see if anyone could help me with this issue.

Thank you very much

Edited by zakmuh on Tuesday 14th December 17:30

Edited by zakmuh on Tuesday 14th December 17:34

Edited by zakmuh on Tuesday 14th December 18:00

[zakmuh]

zakmuh said:

Please see attached pics for references:
When I did the priming, when key in position II fuel comes to inlet hose 4 and banjo bolt 3, and return hose 1 and hose 2.....

Sorry forgot to attach pics earlier...

[zakmuh]

Would it be a bad idea to use like 5 cans of Easy Start and let the engine run on that for a couple of minutes to see if pump builds enough fuel pressure for injectors?

[LordLoveLength]

Are you sure the pump is being driven? You haven’t dropped a coupling inadvertently when you removed it?

[zakmuh]

Yes, I removed and put it back as per VIDA's instruction. So I paid extra attention and care that coupling (connection block) was put back in, to camshaft marking.

Is there a way to check externally if the pump is being driven?

Thanks

[LordLoveLength]

Don’t think so. It should pump fuel. Maybe worth trying a can connected directly to the pump inlet?

[zakmuh]

Thanks

Yup, tries with Easy Start and engine starts straight away but cuts off as soon as spraying stopped. Time to change the high pressure pump, isn't it?

[LordLoveLength]

Seems odd if it worked before. Are you sure all pipes are connected ok? No air leaks?
I’d definitely try a small local container of fuel and a clear pipe to see if it pumps ok then - clamp the original feed to stop it spraying if there’s a lift pump.

[zakmuh]

Yeah I just went and checked it again...all pipes a electrical connections are okay. With ignition key at position II fuel comes to the pump through inlet and return lines, even to the banjo bolt at the top.

But when engine is running with easy start spray, no fuel would leak when I loosen the banjo bolt at top. This tells something or this is how the system works?

[LordLoveLength]

zakmuh said:

Yeah I just went and checked it again...all pipes a electrical connections are okay. With ignition key at position II fuel comes to the pump through inlet and return lines, even to the banjo bolt at the top.

But when engine is running with easy start spray, no fuel would leak when I loosen the banjo bolt at top. This tells something or this is how the system works?

That means the lift pump in the tank is doing its thing.
I’d really suspect a problem with the coupling or drive. Think you need the pump off and check both.
It’s something you did rather than pump failure I’d say. Assuming it worked beforehand.

[zakmuh]

Okay, noted and thanks.

I'll take off the pump again to double check the connection with the inlet camshaft after the school run and update you.

Sorry, out of curiosity asking....shouldn't banjo bolt still get fuel when engine running? It stops and is that why you suspect its the coupling/drive issue there?

[LordLoveLength]

Yes. There should be fuel pressure. Check everything as pumps are expensive

[GreenV8S]

zakmuh said:

Yeah I just went and checked it again...all pipes a electrical connections are okay. With ignition key at position II fuel comes to the pump through inlet and return lines, even to the banjo bolt at the top.

But when engine is running with easy start spray, no fuel would leak when I loosen the banjo bolt at top. This tells something or this is how the system works?

Are you saying you have fuel flowing with the key on that stops when the engine is running?

I think you're referring to the output side of the lift pump. If that's what you see it suggests the lift pump is either being powered off, or is not able to provide adequate flow.

[zakmuh]

GreenV8S said:

Are you saying you have fuel flowing with the key on that stops when the engine is running?

I think you're referring to the output side of the lift pump. If that's what you see it suggests the lift pump is either being powered off, or is not able to provide adequate flow.

Yes the fuel flow stops as soon engine starts to run.

After I read your question, I disconnected fuel inlet pipe from the high pressure pump and connected that to a clear hose then to a container. With key position II fuel flows steadily and as soon as I ran the engine, flow stopped and it wouldn't then flow at all, even after turning off and on back to position II straight away. I then waited for 5 mins and turned key on...fuel flows

Faulty fuel lifter pump? Should change the fuel filter and try again?

Thanks

[LordLoveLength]

As a quick test put the clear pipe on the inlet of the engine fuel pump with the fuel container.
See it it can pull up the fuel direct from the container.

[zakmuh]

Sorry it took awhile to test it

Nope, its not pulling up the fuel from the container. I even raised it to increase the gravity but no.

Could it suspect fuel pressure control valve is not working?

[LordLoveLength]

Really does sound as the pump isn’t being driven.
Suction control valve - doubt it’s the problem. Should suck fuel with it disconnected. Is it physically broken?

If it’s easy enough I think it’s pump off time, check the coupling and make sure the drive turns with the engine

[Penelope Stopit]

Just a thought

Has someone wired an immobiliser and fuel shut-off valve into the system?

[zakmuh]

I didn't do any wiring repair for the car at all. So I don't think immobiliser is stopping fuel as engine is running with easy start?

If its immobiliser then what could have triggered it and how would I check?

I'll remove the pump and put it back tomorrow and see how it'd go.

Thanks

Edited by zakmuh on Wednesday 15th December 19:50

[zakmuh]

No, the valve is not broken physically