Volvo Owners Club Forum - View Single Post - Engine: D5:

Neortic95 · Jun 8th, 2017, 22:58

Hi all, Im new to the forum and new to owning a volvo too. Im hoping someone will be able to shed some light on a problem I have with my V70 D5 185hp 2006.
its covered only 110000 miles with a full history. Ive only had it a few months.

I should also point out that I'm a mechanic of some 25years experience and have access to full diagnostic equipment however this car it giving me somewhat of a headache.

From a day or so after purchase I noticed that it in my opinion was slow to start taking various amounts of cranking to fire, there seemed to be no pattern it was random other than that it ran perfectly loads of power no smoke and returned really good mpg and had no stored faults in the ECM. Then one day it started and ran for a min or two then cut out and wouldn't re-start. I had it recovered to where I work and found that the rail pressure was too low. However after a couple of attempts at starting suddenly it was ok again for a few days then it did it again but this time it would start and idle but if you revved it it would cut out and not restart for at least two hours. So following this I started to go through the usual diag steps. The fuel pressure was slow to rise to its firing pressure of approx 200bar then would be lower than specified at idle it then wouldn't climb fast enough as the revs where increased and eventually cut out. I checked fuel pressure from the tank 6bar and the flow rate is almost 4 litres per min. I did anyway just to eliminate it replace the fuel filter with a genuine volvo one. The fuel pressure out of the HP pump was and instant 1850bar. So I thought the pressure loss must be at the rail as I had also done a leak off test on the injectors and they where fine. I blanked off the injectors from the rail by means of pipe unions and ball bearings and found the pressure was still too low. I first replaced the regulator valve this increased the pressure by 100bar overall but the fault remained so I got a s/h fuel rail and it appeared to fix it but unfortunately the problem has just changed. Now I have good pressure to start and at idle and if driven fairly moderately is fine but when it boosts it will cut out. I stores multiple low fuel pressure faults and won't restart until there are erased. Today I got a known good s/h HP pump mainly out of desperation and although it has improved the starting the fault is still there. Im at a bit of a loss as to why and how the fault has changed and why for such a simple system its proving so difficult to trace the cause. Im hoping someone else has maybe had the same or similar problem. All the other threads Ive read all point to either a filter or tank pump etc but I have eliminated these as the fault. (I have also several times gone back over various steps to recheck my findings)

Any suggestions please ???

Jun 8th, 2017, 22:58	#1
Neortic95 New Member Last Online: Jun 23rd, 2017 21:32 Join Date: Jun 2017 Location: Hastings	fuel pressure issues Hi all, Im new to the forum and new to owning a volvo too. Im hoping someone will be able to shed some light on a problem I have with my V70 D5 185hp 2006. its covered only 110000 miles with a full history. Ive only had it a few months. I should also point out that I'm a mechanic of some 25years experience and have access to full diagnostic equipment however this car it giving me somewhat of a headache. From a day or so after purchase I noticed that it in my opinion was slow to start taking various amounts of cranking to fire, there seemed to be no pattern it was random other than that it ran perfectly loads of power no smoke and returned really good mpg and had no stored faults in the ECM. Then one day it started and ran for a min or two then cut out and wouldn't re-start. I had it recovered to where I work and found that the rail pressure was too low. However after a couple of attempts at starting suddenly it was ok again for a few days then it did it again but this time it would start and idle but if you revved it it would cut out and not restart for at least two hours. So following this I started to go through the usual diag steps. The fuel pressure was slow to rise to its firing pressure of approx 200bar then would be lower than specified at idle it then wouldn't climb fast enough as the revs where increased and eventually cut out. I checked fuel pressure from the tank 6bar and the flow rate is almost 4 litres per min. I did anyway just to eliminate it replace the fuel filter with a genuine volvo one. The fuel pressure out of the HP pump was and instant 1850bar. So I thought the pressure loss must be at the rail as I had also done a leak off test on the injectors and they where fine. I blanked off the injectors from the rail by means of pipe unions and ball bearings and found the pressure was still too low. I first replaced the regulator valve this increased the pressure by 100bar overall but the fault remained so I got a s/h fuel rail and it appeared to fix it but unfortunately the problem has just changed. Now I have good pressure to start and at idle and if driven fairly moderately is fine but when it boosts it will cut out. I stores multiple low fuel pressure faults and won't restart until there are erased. Today I got a known good s/h HP pump mainly out of desperation and although it has improved the starting the fault is still there. Im at a bit of a loss as to why and how the fault has changed and why for such a simple system its proving so difficult to trace the cause. Im hoping someone else has maybe had the same or similar problem. All the other threads Ive read all point to either a filter or tank pump etc but I have eliminated these as the fault. (I have also several times gone back over various steps to recheck my findings) Any suggestions please ???