So long story short i have a fabia vrs with 120k on it, recently the turbo failed on the motorway, it was found the sump was full of diesel leading to me getting the injectors, turbo and cylinder head changed but its keeps cutting out just as its cranked over. the fuel pump relay, high pressure fuel pump and the fuel pump in the tank have been changed but for some reason the mechanic is saying the pressure coming from the pump is way too high sending diesel at quiet high pressure which may have been the cause of all this to begin with, now does anyone have ideas what might be causing this ?

 

 

Dude, it's a PD, fuel delivery pressure is controlled by the unit injectors and the ECU, not the pump.

 

Fuel in the sump is indicative of piston ring blowby, have compression and leakdown tests done before anything else.

so an update according to my mechanic whoever did the last service which was not long before all this happened put the fuel return valve back on the wrong way on the fuel filter and said thats what has caused all the problems, now me not being very car savvy this is flabbergasting and infuriating, is this possible ? 

so an update according to my mechanic whoever did the last service which was not long before all this happened put the fuel return valve back on the wrong way on the fuel filter and said thats what has caused all the problems, now me not being very car savvy this is flabbergasting and infuriating, is this possible ? 

 

It's possible to connect the pipes up the wrong way round so fuel doesn't return to the tank properly, this might cause lift-pump failure.

It's possible to connect the pipes up the wrong way round so fuel doesn't return to the tank properly, this might cause lift-pump failure.

 

could it lead to all the problems i had? 

could it lead to all the problems i had? 

 

No, your original turbo failure is completely unrelated, it's the mess made since then that's deeply worrying.

 

Generally, you simply replace the blown turbo, clean out the pipework, replace the intercooler if full of shrapnel then turn the key and drive off into the sunset.

Diesel in the fuel is usually the injector seals leaking. There is no non return valve as standard that could be fitted the wrong way around. Has your mechanic actually checked the tandem pump pressure and compared the flow to what it should be?. It sounds like possibly the seal has gone in the tandem pump and it's allowing fuel past and air in. The diesel in the oil is probably what killed the turbo due to thinning the oil so much. I would also double check the cam timing is spot on as they will not start if it's out by much.

Edited 17 September, 20169 yr by felicia16v