Fuel pump problems

[DamienW]

I'very just dropped a new engine in my 05 Clio 182 and am having problems getting it started. I think it's down to the fuel pump but what do you make of these symptoms? When the fuel pipe is disconnected from the fuel rail it will only pump for a couple of seconds before stopping. Likewise when it is all connected up. Any ideas why it's stopping? Is there a fuel cut off switch somewhere that has been activated? Any thoughts appreciated.

 

[robzracing]

Check all your earths are connected up. I had this after an engine swap and that was the problem for me.


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[DamienW]

I'very just dropped a new engine in my 05 Clio 182 and am having problems getting it started. I think it's down to the fuel pump but what do you make of these symptoms? When the fuel pipe is disconnected from the fuel rail it will only pump for a couple of seconds before stopping. Likewise when it is all connected up. Any ideas why it's stopping? Is there a fuel cut off switch somewhere that has been activated? Any thoughts appreciated.

Oh, and once it's stopped it won'the start again until the ignition is switched off and back on. Then it just pumps for another couple of seconds. Doesn't pump as the car is cranked over

Check all your earths are connected up. I had this after an engine swap and that was the problem for me.


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Check all your earths are connected up. I had this after an engine swap and that was the problem for me.


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[DamienW]

Checked all earths particularly the one from the gearbox - all good
Correct me if I'm wrong - when the ignition is on the pump should pump continuously with the pressure at the injectors controlled by the pressure regulator in the fuel pump assembly? If the pipe is disconnected from the fuel rail, the pump will keep pumping when the ignition is switched on? Just trying to get things clear in my mind as I try to sort it.

 

[robzracing]

To some extent you are right, but what you are experiencing is the pump priming. The ecu controls this so if pressure doesn’t build in the system it cuts the pump rather than continuously pumping. (Which makes emptying the tank after a race tiresome!)

I discovered an earth behind the passenger headlight was not connected and traced that back to one of the ecu earths.


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[JamesBryan]

The immobiliser will be stopping it.

 

[DamienW]

The immobiliser will be stopping it.

If that is the case (the immobiliser light goes out on the dash when the ignition is turned on), what can I do about it?

 

[DamienW]

To some extent you are right, but what you are experiencing is the pump priming. The ecu controls this so if pressure doesn’t build in the system it cuts the pump rather than continuously pumping. (Which makes emptying the tank after a race tiresome!)

I discovered an earth behind the passenger headlight was not connected and traced that back to one of the ecu earths.


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I'll check that out tomorrow

 

[JamesBryan]

If that is the case (the immobiliser light goes out on the dash when the ignition is turned on), what can I do about it?

If it's not the immobiliser then it could be the TDC sensor.

 

[DamienW]

I'll check that out tomorrow

Checked and cleaned the earth as you suggested and the pump is now running. Still problems though! After much cranking it eventually fires on a couple of cylinders and chugs then dies. Every now and then though it'll chug for a bit and then fire up on all four and sounds good - but it'll only run at 3000rpm or so. Last time it did this the dash pinged after a bit and the stop light came up. Couple of DTCs for manifold pressure and air temp sensor circuits though both the sensors are new. Crank position sensor is new too. Any ideas?

 

[robzracing]

Checked and cleaned the earth as you suggested and the pump is now running. Still problems though! After much cranking it eventually fires on a couple of cylinders and chugs then dies. Every now and then though it'll chug for a bit and then fire up on all four and sounds good - but it'll only run at 3000rpm or so. Last time it did this the dash pinged after a bit and the stop light came up. Couple of DTCs for manifold pressure and air temp sensor circuits though both the sensors are new. Crank position sensor is new too. Any ideas?

Both O2 sensors plugged in? And check for air leaks on the inlet assembly. Other than that you may have dirt in the fuel rail or loose connection on injectors. At least you know it has potential to run properly. Just needs to be a process of elimination.
I'm sure others will have suggestions too but if cleaning the earths up has helped I'd suggest your problem is probably electrical.

 

[DamienW]

Both O2 sensors plugged in? And check for air leaks on the inlet assembly. Other than that you may have dirt in the fuel rail or loose connection on injectors. At least you know it has potential to run properly. Just needs to be a process of elimination.
I'm sure others will have suggestions too but if cleaning the earths up has helped I'd suggest your problem is probably electrical.

Thanks Mate. I'll continue the search though i'm feeling like putting the old girl on the scrap heap!