96 850 tdi cutting out help

nottsgreent5 · Sep 9th, 2012, 14:48

hi all have a few problems with a 850 tdi runs perfect then randomley cuts out only code i had was air flow meter changed that for a known working 1 and its still the same done the filters and no difgerence any idears lol. ?

BillB · Sep 11th, 2012, 22:33

I've just had this very problem with my 00 V70 Tdi (your engine). I was getting ECM0029 which relates to fuel quantity when warm so I suspected a pump issue. Took it to a Bosch injection specialist (a Volvo indi or main dealer would only have changed the pump which is expensive) who knows injection pumps inside out and has some very impressive test equipment. He ended up re-soldering the connector to the e-lab valve (fuel shut-off valve) which seems to have cured it i.e. it seemed to have an intermittent dry joint.

The simple checks are the fuel pump electrical connections, the fuel pump relay (in the main fuses compartment) and, possibly in your case, the MAF connector. I realise that you had an air flow fault code but there are various reasons that might cause it to cut out. The ECU is making thousands of calculations all the time and if some parameter goes out of range then it might shut down the fuel flow,air flow being one of them. Basically, the Tdi has a mechanical fuel pump i.e. the fuel pressure is produced mechanically and the ECU has no controlof this. The electrical part of the pump controls fuel flow and this is adjusted according to air flow, accelerator position and ECU decisions. Regards.

antalpt · Sep 14th, 2012, 15:02

Suggestion,

Check the electric injector connector.

Sep 9th, 2012, 14:48	#1
nottsgreent5 Member Last Online: Jan 31st, 2024 21:07 Join Date: Nov 2010 Location: nottingham	96 850 tdi cutting out help hi all have a few problems with a 850 tdi runs perfect then randomley cuts out only code i had was air flow meter changed that for a known working 1 and its still the same done the filters and no difgerence any idears lol. ?

Sep 11th, 2012, 22:33	#2
BillB VOC Member Last Online: Apr 24th, 2024 13:58 Join Date: Dec 2002 Location: Bristol	I've just had this very problem with my 00 V70 Tdi (your engine). I was getting ECM0029 which relates to fuel quantity when warm so I suspected a pump issue. Took it to a Bosch injection specialist (a Volvo indi or main dealer would only have changed the pump which is expensive) who knows injection pumps inside out and has some very impressive test equipment. He ended up re-soldering the connector to the e-lab valve (fuel shut-off valve) which seems to have cured it i.e. it seemed to have an intermittent dry joint. The simple checks are the fuel pump electrical connections, the fuel pump relay (in the main fuses compartment) and, possibly in your case, the MAF connector. I realise that you had an air flow fault code but there are various reasons that might cause it to cut out. The ECU is making thousands of calculations all the time and if some parameter goes out of range then it might shut down the fuel flow,air flow being one of them. Basically, the Tdi has a mechanical fuel pump i.e. the fuel pressure is produced mechanically and the ECU has no controlof this. The electrical part of the pump controls fuel flow and this is adjusted according to air flow, accelerator position and ECU decisions. Regards.

Sep 14th, 2012, 15:02	#3
antalpt Junior Member Last Online: Jan 20th, 2021 15:41 Join Date: May 2010 Location: Europe	Suggestion, Check the electric injector connector.

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