vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing

Honest John Back Room » Technical matters
View Threaded
Sun 25 Sep 2011 00:40
vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing - cookvale

Hello all

I have a 2001 y reg passat estate tdi avb engine with 264000 miles on the clock wich has just had its first clutch & turbo replacement , since i got it back it has developed a missfire while idleing and it doesnt pull like i thought it would considering it has a new turbo. I took it back to the garage and they tested the turbo , they say it is "spooling up "perfectly and they cannot find any leaks on the pipes , they have put it on the computer & it shows no faults. the garage says it could be a faulty injector or the wiring loom or the pressure boost valve or even a dirty fuel filter but its only done 1000 miles since the last service

has anybody suffered this problem or maybe know how to solve it , i cant afford to keep throwing money at it but i cant afford to change it either . any help would be greatly appreciated

Reply | Report as offensive | Link
Sun 25 Sep 2011 20:44
vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing - Big John

Turbo and/or leaks should have any affect on idle. As you have just had a new clutch and turbo fitted my money is on the injector wiring loom. They are prone to failure as they degrade in time due to oil contact – particularly when disturbed!!

P.S. What happened to the previous turbo, can I presume no debris got into the engine causing valve damage? – probably not via intercooler – just have to ask the question.

Reply | Report as offensive | Link
Mon 26 Sep 2011 09:06
vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing - Big John

Slight typo - The turbo and associated air leaks should NOT have any affect on idle.

Edited by Big John on 26/09/2011 at 09:07

Reply | Report as offensive | Link
Thu 21 Jun 2012 22:45
vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing - ADAMKHAN
I had a vw passat with an AVB engine and it developed a misfire, at around 60,000 miles, i changed the injectors but no luck, changed the fuel filter, again no luck.

The problem was with the fuel pump in the tank, it was feeding the fuel forward far to slowly and this was causing the misfire, and when i started the car up at any point i would have to wait about ten seconds before moving off or otherwise it would cut out, and i would have to sit there trying to get it to turn over for about 30 seconds before it started.

the rear fule pump isnt too pricey, it cost me £210 and took about 10mins to fit. easy way to test if this is the problem is to connect a standard vacum break bleeder and to the fuel feed pipe before the fuel pump and see what happens, the instant you press the plunger the fuel should fill the pipe instantly and completely, if it fills slowly then thats the problem.

any garage can check this for you.
Reply | Report as offensive | Link
Thu 21 Jun 2012 23:22
vw passat 1.9 tdi ( 100bhp avb engine ) - no power & missfires while idleing - Big John

After things have been disturbed my money is still on the injector wiring loom! The wiring goes brittle in time and breaks if disturbed in any way.

Edited by Big John on 21/06/2012 at 23:24

Reply | Report as offensive | Link

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....