Fuel starvation 1.6 JX

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Rdav1s
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Fuel starvation 1.6 JX

Post by Rdav1s »

Fuel feed issue with Syncro 1.6 JX

Afternoon everyone,

I have a bit of an issue, well my bus does !!

I recently changed the corroded fuel tank straps and fuel filter and now have fuel issues. Here’s what I did and the results.

1. Disconnected the fuel line at the tank end to drain the tank as I was going to remove it.
2. Removed the corroded straps. In order to do this I lowered the tank 4 inches and 4 inch forwards.
3. Installed new straps.
4. Reconnected fuel line.
5. Changed the fuel filter. 
6. Put 2 gallons of fresh diesel into the tank.

Initially all seemed well for a 200 metre test drive. Now when I start it, it fires straight up but if I try and rev it, she cuts out. I have noticed loads of air in the feed and return pipes when it’s roughly ticking over.  As part of my trouble shooting I filled the fuel filter up with diesel and it runs great..... until the fuel in the filter runs out. That says to me that the issue is between the tank and the filter, or could it be the breather system. Also, the Bentley manual shows a fuel pump, if it has one, where is it located :-s
i have checked that the feed and return pipes are free and not trapped when I refitted the tank as well so hopefully that’s ruled out.

any help would be massively appreciated as always.

thanks, Rob
 

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Titus A Duxass
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Re: Fuel starvation 1.6 JX

Post by Titus A Duxass »

Dirt in the bottom of the tank probably.
It could have been stirred up and is blocking the tank outlet.
You should drop the tank completely and flush it out.

There is no other fuel pump.
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davidoft1
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Re: Fuel starvation 1.6 JX

Post by davidoft1 »

How long have you had it running ?

Rdav1s
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Re: Fuel starvation 1.6 JX

Post by Rdav1s »

Titus A Duxass wrote:Dirt in the bottom of the tank probably.
It could have been stirred up and is blocking the tank outlet.
You should drop the tank completely and flush it out.

There is no other fuel pump.
I guess I should remove the pipe from the tank end first and see what the flow rate is like as it comes out maybe?

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Last edited by Rdav1s on 03 Oct 2020, 13:07, edited 2 times in total.

Rdav1s
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Re: Fuel starvation 1.6 JX

Post by Rdav1s »

davidoft1 wrote:How long have you had it running ?
It will run for a couple of minutes and "hunt" like crazy anywhere between 500 and 1500 rpm. If I try and feather the accelerator, it protests and cuts out

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davidoft1
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Re: Fuel starvation 1.6 JX

Post by davidoft1 »

Rdav1s wrote: 03 Oct 2020, 13:09
davidoft1 wrote:How long have you had it running ?
It will run for a couple of minutes and "hunt" like crazy anywhere between 500 and 1500 rpm. If I try and feather the accelerator, it protests and cuts out

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That’s exactly what it will do when you’ve had the fuel lines off, but how long have you run it for? A couple of minutes or half an hour ?

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silverbullet
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Re: Fuel starvation 1.6 JX

Post by silverbullet »

If it will start and idle, open the air bleed on the fuel filter to vent any air, then crack off the injector pipe nuts one at a time to bleed the air out.
That usually clears mosts IDI diesel problems, they are simple things.
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Rdav1s
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Re: Fuel starvation 1.6 JX

Post by Rdav1s »

davidoft1 wrote:
Rdav1s wrote: 03 Oct 2020, 13:09
davidoft1 wrote:How long have you had it running ?
It will run for a couple of minutes and "hunt" like crazy anywhere between 500 and 1500 rpm. If I try and feather the accelerator, it protests and cuts out

Sent from my SM-G390F using Tapatalk


That’s exactly what it will do when you’ve had the fuel lines off, but how long have you run it for? A couple of minutes or half an hour ?
I run it for as long as it decides (normally a couple of mins) I then restart immediately after it cuts out and it may run rough again for a couple of mins before cutting out. If I try and accelerate too much, it cuts out
The thing is, I refilled the fuel filter and can drive it, till that filter full runs out. Cheers

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Rdav1s
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Re: Fuel starvation 1.6 JX

Post by Rdav1s »

silverbullet wrote:If it will start and idle, open the air bleed on the fuel filter to vent any air, then crack off the injector pipe nuts one at a time to bleed the air out.
That usually clears mosts IDI diesel problems, they are simple things.
Cheers, I will try that. Where is the bleed valve on the filter? Is it the drain tap on the bottom?Image

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Timburrows
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Re: Fuel starvation 1.6 JX

Post by Timburrows »

the white thing on the filter has an o ring that can leak causing air to get in,worth checking

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silverbullet
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Re: Fuel starvation 1.6 JX

Post by silverbullet »

Rdav1s wrote: 03 Oct 2020, 16:21
silverbullet wrote:If it will start and idle, open the air bleed on the fuel filter to vent any air, then crack off the injector pipe nuts one at a time to bleed the air out.
That usually clears mosts IDI diesel problems, they are simple things.
Cheers, I will try that. Where is the bleed valve on the filter? Is it the drain tap on the bottom?Image

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Some filters have a top bleed screw, some dont. The bottom fitting is a water drain.
+1 on checking the o-ring on the return valve (?)
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Cecil
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Re: Fuel starvation 1.6 JX

Post by Cecil »

possible cause,
Perished or loose fitting fuel pipes(or the previously mentioned thermo valve on the filter) may not leak fuel but may allow air to enter so that the the injection pump draws air in instead of fuel from the tank.

Rdav1s
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Re: Fuel starvation 1.6 JX

Post by Rdav1s »

SUCCESS  :D

I usually change one thing and see the result so that I can identify the cause, it was too cold and wet the morning so I just went for it. I carried out all of the following.

1. Disconnected all pipes to the filter and removed filter and bracket. The bracket is a home made solution and was ill fitted and causing the majority of the weight to be taken by the thermo value.
2. Confirmed that all pipes were free and not caught. A tug on the feed pipe at the filter end resulted in a freeing up of the pipe give slight play!!!
3.  The feed pipe at the filter connection was shortened by 1/4' in order to remake the end. I did the same for the filter to injection pump pipe.
4. Inspected and cleaned the thermo valve and 'O' ring. I noticed an arrow on the thermo valve and it was fitted pointing towards the injection pump. As this is the return pipe I have swapped it around so that the arrow faces the tank.

After 5 mins of rough running it has smoother out and is back to normal tickover and revving. I've still to take it on a road test and see what its like under load. Any comments on the thermo valve direction arrow would be appreciated.
A massive thank you to everyone for their suggestions, 80-90s to the rescue again.

:ok :ok :ok :ok :ok
 

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