Mk1 V70 tdi Misfire at operating temp

russ68 · Jul 27th, 2012, 19:57

Hi guys,
I'm looking for inspiration with a misfiring problem I'm having with my '98 V70 tdi.
When cold it runs sweet as a nut, but once it warms up it becomes a violently insane bucking bronco. The problem started a few weeks ago and is getting worse.
The specifics of the symptoms are; it's ok,with occassional hiccups if the revs are kept low and a very small amount of throttle maintained, but open the throttle or let it get over about 1500rpm and it's pretty much undriveable. Pulling away from junctions is achieved by burying the throttle and slipping the clutch through the gears until about 25mph when it can just about run in 5th gear and bimble along up to about 40mph. Sitting in neutral with the throttle held constant at what would be around 3000rpm, the revs go up and down sharply, so sharply I'm now thinking it's an electrical fault rather than fuel. It's like a switch is being flicked at rapid, but random intervals. It's so violent, I'm of the mind it's not just a single cylinder misfiring, but the whole engine.
So far I've changed the fuel filter, the temp sensor to the ecu and the MAF sensor.
Have any of you guys had this problem and if so, how was it resolved ?
Thanks, Russell

outnumbered · Jul 27th, 2012, 20:00

when was the dynamic pump timing last checked. this can cause hot and cold start running issues.
mike

russ68 · Aug 21st, 2012, 16:10

Yep, that's exactly what the problem's been. Resolving it has unmasked a handful of other issues, but you wouldn't expect anything else would you?

Jul 27th, 2012, 19:57	#1
russ68 Junior Member Last Online: Jul 7th, 2019 16:07 Join Date: Sep 2011 Location: newcastle	Mk1 V70 tdi Misfire at operating temp Hi guys, I'm looking for inspiration with a misfiring problem I'm having with my '98 V70 tdi. When cold it runs sweet as a nut, but once it warms up it becomes a violently insane bucking bronco. The problem started a few weeks ago and is getting worse. The specifics of the symptoms are; it's ok,with occassional hiccups if the revs are kept low and a very small amount of throttle maintained, but open the throttle or let it get over about 1500rpm and it's pretty much undriveable. Pulling away from junctions is achieved by burying the throttle and slipping the clutch through the gears until about 25mph when it can just about run in 5th gear and bimble along up to about 40mph. Sitting in neutral with the throttle held constant at what would be around 3000rpm, the revs go up and down sharply, so sharply I'm now thinking it's an electrical fault rather than fuel. It's like a switch is being flicked at rapid, but random intervals. It's so violent, I'm of the mind it's not just a single cylinder misfiring, but the whole engine. So far I've changed the fuel filter, the temp sensor to the ecu and the MAF sensor. Have any of you guys had this problem and if so, how was it resolved ? Thanks, Russell

Jul 27th, 2012, 20:00	#2
outnumbered Lunatic from Wakefield Last Online: Apr 16th, 2023 06:33 Join Date: Dec 2004 Location: wakefield	when was the dynamic pump timing last checked. this can cause hot and cold start running issues. mike __________________ 2012 volvo xc90 Executive Buccaneer Bermuda 2021

Aug 21st, 2012, 16:10	#3
russ68 Junior Member Last Online: Jul 7th, 2019 16:07 Join Date: Sep 2011 Location: newcastle	Yep, that's exactly what the problem's been. Resolving it has unmasked a handful of other issues, but you wouldn't expect anything else would you?

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