2.5 tdi injection pump swapping

[Steve-greek]

Im hoping there will be someone on here that can help me answer this question.

I bought a 2.5tdi audi convertiable non runner for a bit of summer fun. Main fuel pump is the faulst, i had sent the fuel pump ecu for repair but its dead.

so, One of the grand plans i had for the car was some more BHP once i got it up and running. Now i know i need to get a recon fuel pump can i / am i best to source one from a 180 quattro. They have the same ecu number but different part number on the mechanical pump.

The car is corrently 163 bhp. but i wanted to get a turbo from the 3.0tdi as i have read and bigger injection nozzles. Im just not sure which pump will be best for BHP gains.

 

[Steve-greek]

Anyone able to help me out of this one?

 

[abyrne153]

Chris Adams (adamss24) is the man for this.

 

[Steve-greek]

I have read a lot of Chris Adams post. I was hoping he would help but I think he's gone dark since may.

Anyway I bit the bully and bought and fitted the 180 bhp all road pump. Car is still not running. Had the pump coded into the car with vag com. Used a 12v fuel pump plumbed into the fuel filter to force the diesel straight into the vp44. It just refuses to go. Only fault code showing is the needle lift sensor. I know it needs to be sorted but waiting to hear it run before a throw more cash at it.

The only thing I find strange is there is a buzzing noise coming from the fuel pump with the ignition on. I read it could be the quantity adjuster?

Any help would be much appreciated. This 'little' summer project is really fighting me.

 

[abyrne153]

Should still start even with needle lift sensor fault. Are you getting diesel at the injectors? These are a pig to bleed at times. Bleed the filter by sickening the small bleed screw and turn the key and just hit the starter for a second. That starts the lift pump in the tank for a few seconds and you should get a spurt of fuel or air from the bleeder. If not I'd suspect the the lift pump is faulty. If the filter bleeds ok then remove the feed pipe to the pump at the filter and carefully fill with fuel and try to get it fitted without letting air in. Then slacken maybe 4 out of 6 injectors and turn the engine over. Use plenty of rags to catch the spray. If and when the engine starts or tries to start then switch off and tighten all up and see will it run. If not then I would check static timing and make sure all is good before trying again. You will usually get code if the injection pump is faulty. Quantity adjuster is within the pump and if faulty usually throws a code and requires a pump rebuild. Another thing is that the car won't start if the tank is empty. It is a safety mechanism to prevent the vp44 running dry.

 

[Steve-greek]

Should still start even with needle lift sensor fault. Are you getting diesel at the injectors? These are a pig to bleed at times. Bleed the filter by sickening the small bleed screw and turn the key and just hit the starter for a second. That starts the lift pump in the tank for a few seconds and you should get a spurt of fuel or air from the bleeder. If not I'd suspect the the lift pump is faulty. If the filter bleeds ok then remove the feed pipe to the pump at the filter and carefully fill with fuel and try to get it fitted without letting air in. Then slacken maybe 4 out of 6 injectors and turn the engine over. Use plenty of rags to catch the spray. If and when the engine starts or tries to start then switch off and tighten all up and see will it run. If not then I would check static timing and make sure all is good before trying again. You will usually get code if the injection pump is faulty. Quantity adjuster is within the pump and if faulty usually throws a code and requires a pump rebuild. Another thing is that the car won't start if the tank is empty. It is a safety mechanism to prevent the vp44 running dry.

Thanks for your help, im hoping you might be able to help a little more as the problem continues.

I had an electrician with vag com come back up and plug in the car, this time i ended up with fault code showing no communication with the pump. Scanned the live data and it was showing signal voltage to the vp44 ecu but nothing coming out. So we thought the second hand pump was at fault.
So whipped of the ECU and sent to Actronics. Tested and come back as no faults.

More than half a tank of fuel. Am i correct in thinking its only the quattros that have a lift pump? As i read they have a funny shape fuel tank due to prop shaft and diff.

What code would a quantity adjuster throw up? as i still have the old pump and would be quite tempted to have a go and strip the pair of the pumps down to try and make one. The first pump had ecu issues.

 

[abyrne153]

01268 Quantity Adjuster (N146) Defect. But the this is all within the pump so a QA fault means a pump fault. Just bear in mind you have only tested the ECU on this pump and not the pump itself. I'm not a fan of fixing the ecu as a standalone thing. These pumps are precision built and the ecu is set up to match the pump on a test bench. Any messing with the ECU at all can cause all sorts of running problems. The pump mechanics could be faulty - maybe the advance solenoid is seized for example. The only way to be sure is to get the whole pump to a specialist Bosch agent and test it properly. However before that, are you definitely sure the pump is coded properly ? Also are you similarly sure that the static timing is good? Is there any diesel getting to the injectors at all ? There are threads on here somewhere by Chris Adams that give diagnostic information on the VP44 pump in relation to the correct voltage at various pins on the pump ecu. Check these out also and see how that matches to yours. Is the EGR valve on your car still connected? If so try blanking it off as there was a similar starting problem on here before and it turned out the EGR valve was stuck open.

 

[donsajid]

Alright mate I think you should get in touch with shark performance at www.sharkperformance.co.uk

I had my injection pump replaced on my 2.5 tdi and they were the only ones who were able to sort it aside from dealer who wanted silly money + tow fees.
These guys came out to me and sorted it.