TDi fuel pump comms failure?

[SilverSwede]

Hi,

My '98 TDi has just had a replacement fuel pump fitted and all is not going well just yet.

The engine is back up and running but the the ECU appears not to be communicating and ODB port appears dead and has no data (although it is powered up).
The pump has been set up with a dial gauge and should be spot on but it is not on the sweet spot yet with some smoke still present and difficult cold starting.
Any ideas most welcome. Thank you.

[Baffler]

Seeing as the pump multiplug was disturbed during replacement I would be checking this fellow first just in case the multiplug tabs aren't fully engaged and, whilst in there, try and have a look up with a mirror to ensure no pins have gone askew.

[SilverSwede]

No joy with the multi-pin plug. Looks ok.
It's running the same as before ie. quite harsh sounding but reliable. Uses no oil and very good shape for it's 240K miles. I have a very long run to do in May and don't want to risk pounding the hell out of the bottom end if she's a tad too advanced.
Need to locate an old-school Volvo technician or any good diesel technician who is able to diagnose and repair in the Cornwall/Devon area. Any suggestions much appreciated.

[Iceonfire]

I think there is a fuse under the dash somewhere for the OBD port. Might be worth checking.

[Baffler]

Originally Posted by SilverSwede

The pump has been set up with a dial gauge and should be spot on but it is not on the sweet spot yet with some smoke still present and difficult cold starting.

Originally Posted by SilverSwede

It's running the same as before ie. quite harsh sounding but reliable. Uses no oil and very good shape for it's 240K miles. I have a very long run to do in May and don't want to risk pounding the hell out of the bottom end if she's a tad too advanced.

Smoke and slow starting would indicate it's a degree or two, possibly more, retarded. If it was too advanced it would start on half a revolution. You could try bring the pump camshaft pulley forward a mill or two.

Originally Posted by SilverSwede

Need to locate an old-school Volvo technician or any good diesel technician who is able to diagnose and repair in the Cornwall/Devon area. Any suggestions much appreciated.

Or perhaps make contact with Rudi_Dudi on here.


Also test each of the fuses in the engine bay fusebox for continuity. I think there is one in there for the MAF meter and could be related.

[Slevin]

Hi,


i dont want to open another topic so I just write it here.

I have a 99 V70 with MSA15.8. It feels powerless for me( I also have a MK2 2.5T with Shemtek tune though).
It picks up slowly, there is some power above 2000rpm and above 3000 it feels like the boost is spiking. It pulls unevenly. The engine starts right up when cold/hot, fuel comsumption is OK, there is a normal amount of smoke at WOT but i think it should be quicker. Ohh yes, forgot to mention, it has a Vdash tune on it as well.

Engine has just been "semi-rebuilt" due to a aux belt failure. Rebuild head, rebuilt injectors, new piston rings etc; but the weakness problem existed before rebuild,too.

I tried another MAF and TCV from another car, no change. There are no DTCs stored, actual timing is 0.5-1 degree off compared to the desired value. Reading was made with VIDA.
Is there a known common fault in the injection pump's control module like there is in the VP44's?

[Baffler]

Originally Posted by Slevin

Hi,


i dont want to open another topic so I just write it here.

I have a 99 V70 with MSA15.8. It feels powerless for me( I also have a MK2 2.5T with Shemtek tune though).
It picks up slowly, there is some power above 2000rpm and above 3000 it feels like the boost is spiking. It pulls unevenly. The engine starts right up when cold/hot, fuel comsumption is OK, there is a normal amount of smoke at WOT but i think it should be quicker. Ohh yes, forgot to mention, it has a Vdash tune on it as well.

Engine has just been "semi-rebuilt" due to a aux belt failure. Rebuild head, rebuilt injectors, new piston rings etc; but the weakness problem existed before rebuild,too.

I tried another MAF and TCV from another car, no change. There are no DTCs stored, actual timing is 0.5-1 degree off compared to the desired value. Reading was made with VIDA.
Is there a known common fault in the injection pump's control module like there is in the VP44's?

These 2.5D's can suffer "poor performance" due to a failing MAF meter but, seeing as you have tried a known good one, check the condition of the rubber hose going from the inlet manifold to the MAP sensor located on the strut tower. Also make sure the nipple on the inlet manifold is clear of crud using a suitable drill bit.

And pressure test the intercooler just in case it's damaged or cracked.

[Baffler]

Any luck with yours, SilverSwede?

[Slevin]

MAP's hose was replaced earlier, the nipple is clean the whole inlet manifold was cleaned and burnt out during the rebuild. Replaced the TCV again for another one which isn't listed for 2.5D and it feels OK now.