TDi fuel pump comms failure?
 

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.

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.

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.

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

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.

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.

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.

Any luck with yours, SilverSwede?

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.

Pump timing update..
 

Hi and thanks for asking Baffler,

In short, no real progress although the replacement pump seems to have settled in and is returning better mpg than the old pump - (mostly rural back roads driving here and getting 43-45mpg rather than 35-40 before.) Crept up to 50mpg on the 30 mile run up the A30 to Exeter recently - so can't be that far out?
Engine now starts in a revolution (a bit too briskly?) and pulls well but still black smokes when pushed hard.

All fuses ok but I've not tried altering the pump timing myself this time as I've lost heart a bit since I can no longer get any feedback from the dongle/obd port.

This is my third V70 and I remember the previous two seemed silky smooth from the cabin compared to this one but I am confident it will convey me and Mrs to Scotland in a couple of weeks time without major issue. I would be happy to make a detour if there are any timing guru's on or near the route from Cornwall to Scotland!? (I'd have to bribe my navigator of course!)