In Tank Fuel Pump

G

Graham2704

Member
Hi,

After going all out this year to getting my little car working better I am Looking at getting a new In tank fuel pump.

I have so far this year done the following:

New timing belt kit & water pump.
New Tappets.
New Genuine Injectors.
New Genuine Throttle.
New EGR.
Full service with Genuine parts.

But still have a bit of hesitation like fuel starvation when I take my foot off the accelerator it just seems to Die like no fuel there.

I have seen this but the start is 6U where ours are 8Z the rest of the numbers match when I cross ref does the 6U matter or not ?.

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Thanks for any advice Graham.
 
Ah, Most of my experience is with diesels which will run quite happily without the in tank lift pump working at all. Can't really vouch for petrol. Is it possible to disconnect the fuel supply from the injectors and put it in a jar, then turn on the ignition and see if you get any fuel flow. Surely it is better to test the pump that just replace it?

Trevor
 
Hi,

on the petrol the in tank electric pump generates all the fuel pressure for the injectors.
There are easier and cheaper things to look at before replacing the fuel pump when suspecting fuel starvation such as the fuel filter and the fuel pressure regulator (the round shiny thing on the fuel rail) and its controlling vacuum hose. The vacuum supply to the fuel pressure regulator causes it to increase the pressure and so amount of fuel available at higher engine revs (when there is more vacuum).

A sign of fuel starvation I would expect to be hesitation on hard acceleration (foot on the floor) as the supply of fuel from the pump is insufficient to run the engine on load (rather than when you lift off).

Have you run the Throttle body and EGR adaption after replacement? The EGR in particular is important as without adaption after a change of part, the new part can be damaged and also cause running issues such as the engine dying when lifting off the throttle.

To test the fuel system you will need to run the pump manually and record how much fuel is supplied. This should be done from the fuel pump output hose rather than the injectors. You can't test the injectors as you need to run the engine to get the injectors to produce fuel, but if you measure the output from the injectors, they will need to be out of the engine so it won't run!

To test, remove fuse 18. This is the fuel pump fuse. You can then connect a +ve supply wire to the left fuse pin to activate the pump.
To measure the fuel, use a large jug, e.g. 1 liter. Remove the fuel return pipe from the fuel rail in the engine bay and then connect another pipe on the fuel rail in its place. Run this pipe into the jug.
When the pump is run, fuel will flow into the jug. Run the pump for 15 seconds and measure the supply voltage while the pump is running. Note if you measure the voltage at the battery, subtract 2 to get the voltage at the pump.
Once run, look up the voltage and volume of fuel on this chart:

1576970020836.png


If the volume and voltage plotted fall below the line you have a fuel supply problem.
This may be caused by a defective pump, blocked fuel filter or faulty fuel pressure regulator as this tests the whole system and fuel available at the injectors.

Remember that Petrol is very flammable so be safe!

regards

Andrew
 
ajsellors said:
Hi,

on the petrol the in tank electric pump generates all the fuel pressure for the injectors.
There are easier and cheaper things to look at before replacing the fuel pump when suspecting fuel starvation such as the fuel filter and the fuel pressure regulator (the round shiny thing on the fuel rail) and its controlling vacuum hose. The vacuum supply to the fuel pressure regulator causes it to increase the pressure and so amount of fuel available at higher engine revs (when there is more vacuum).

A sign of fuel starvation I would expect to be hesitation on hard acceleration (foot on the floor) as the supply of fuel from the pump is insufficient to run the engine on load (rather than when you lift off).

Have you run the Throttle body and EGR adaption after replacement? The EGR in particular is important as without adaption after a change of part, the new part can be damaged and also cause running issues such as the engine dying when lifting off the throttle.

To test the fuel system you will need to run the pump manually and record how much fuel is supplied. This should be done from the fuel pump output hose rather than the injectors. You can't test the injectors as you need to run the engine to get the injectors to produce fuel, but if you measure the output from the injectors, they will need to be out of the engine so it won't run!

To test, remove fuse 18. This is the fuel pump fuse. You can then connect a +ve supply wire to the left fuse pin to activate the pump.
To measure the fuel, use a large jug, e.g. 1 liter. Remove the fuel return pipe from the fuel rail in the engine bay and then connect another pipe on the fuel rail in its place. Run this pipe into the jug.
When the pump is run, fuel will flow into the jug. Run the pump for 15 seconds and measure the supply voltage while the pump is running. Note if you measure the voltage at the battery, subtract 2 to get the voltage at the pump.
Once run, look up the voltage and volume of fuel on this chart:

View attachment 59942

If the volume and voltage plotted fall below the line you have a fuel supply problem.
This may be caused by a defective pump, blocked fuel filter or faulty fuel pressure regulator as this tests the whole system and fuel available at the injectors.

Remember that Petrol is very flammable so be safe!

regards

Andrew
Click to expand...
@Doodsea ...I've just read about getting the egr valve adapted on here, maybe @ajsellors could help you with how to do this?
 
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