hesitation when accelerating 1.9d

HalV40 · May 15th, 2018, 21:58

When I accelerate gently I get a bit of lumpiness/hesitation just under 2000RPM, normally I would put this down to the EGR needing a clean but I have unplugged my EGR in the closed state. (I'm guessing it's closed when the engine is off!).
Any ideas what could cause this hesitation?
I've cleaned the MAF, fitted new air filter, and given it a good thrash up the motorway to clear it out, no change.

martin93 · May 15th, 2018, 22:44

Usually when an EGR fails, the oily carbony rubbish causes the valve to stick open slightly, therefore you won't know whether it is actually closed. Best thing to do would be take it off and inspect. From those symptoms it does sound EGRish.

bobthecabbage · May 15th, 2018, 22:47

Check the EGR and if all is well, maybe start to suspect the MAF.

How old is the MAF, has it been replaced? Is it genuine?

It may develop as mine did, in the end it was all smoke and no power and engine management light on.

Baffler · May 17th, 2018, 10:51

Quote:

I've cleaned the MAF, fitted new air filter, and given it a good thrash up the motorway to clear it out, no change.

When was the fuel filter last changed?

baldmosher · May 19th, 2018, 10:33

EGR clean out
MAF (swap it and see, you'll find one for £15 if you're patient)
Fuel filter
Stick some Redex in case it's injector crud

I did all that and it was MAF in the end

HalV40 · May 28th, 2018, 22:16

Thanks Baffler, fuel filter was my next port of call, I thought that would cause high fuel demand starvation but I'll change it anyway, it's well overdue!

Any tips on how to get the EGR valve closed even with carbon build up? I couldn't get the valve out when I tried (hence unplugging it).

Baffler · May 29th, 2018, 00:39

Quote:

Originally Posted by HalV40

Thanks Baffler, fuel filter was my next port of call, I thought that would cause high fuel demand starvation but I'll change it anyway, it's well overdue!

Being common rail I think the fuel filter interval on these is every 20k miles so, if you've no record of it being replaced, no harm to change it. You might also want to take a peek at the pick up in the tank (if you can't view the pics I can send them to you).

Quote:

Originally Posted by HalV40

Any tips on how to get the EGR valve closed even with carbon build up? I couldn't get the valve out when I tried (hence unplugging it).

If I'm not mistaken you can rotate the EGR valve so the apertures are facing away from the inlet. Try a Stiltson (pipe wrench) on the triangular flange.

May 15th, 2018, 21:58	#1
HalV40 Junior Member Last Online: Sep 27th, 2020 17:45 Join Date: May 2017 Location: Lichfield	hesitation when accelerating 1.9d When I accelerate gently I get a bit of lumpiness/hesitation just under 2000RPM, normally I would put this down to the EGR needing a clean but I have unplugged my EGR in the closed state. (I'm guessing it's closed when the engine is off!). Any ideas what could cause this hesitation? I've cleaned the MAF, fitted new air filter, and given it a good thrash up the motorway to clear it out, no change.

May 15th, 2018, 22:44	#2
martin93 Member Last Online: Aug 1st, 2019 19:17 Join Date: Aug 2013 Location: Dorset	Usually when an EGR fails, the oily carbony rubbish causes the valve to stick open slightly, therefore you won't know whether it is actually closed. Best thing to do would be take it off and inspect. From those symptoms it does sound EGRish. __________________ Current: 2003 VW Passat 1.9TDI, 1979 Saab 99 turbo, 1968 MGB GT,

May 15th, 2018, 22:47	#3
bobthecabbage Premier Member Last Online: Aug 12th, 2020 21:26 Join Date: Mar 2014 Location: Plymouth	Check the EGR and if all is well, maybe start to suspect the MAF. How old is the MAF, has it been replaced? Is it genuine? It may develop as mine did, in the end it was all smoke and no power and engine management light on. __________________ '04 V40 1.9D

May 19th, 2018, 10:33	#5
baldmosher moshmobile driver Last Online: Apr 22nd, 2023 16:07 Join Date: Nov 2010 Location: Warrington View Photos By: baldmosher	EGR clean out MAF (swap it and see, you'll find one for £15 if you're patient) Fuel filter Stick some Redex in case it's injector crud I did all that and it was MAF in the end __________________ baldmosher™ Drives: 63 V60 R-Design Lux Nav P* 106K Kill List: 07 S40 SE Sport D5 120K V40 SLux 1.9D 306K V40 S 1.9D 152K VW T4 LDV Pilot Golf GL 1.9TD Saxo 1.1i Fiesta 1.0 Pop

May 28th, 2018, 22:16	#6
HalV40 Junior Member Last Online: Sep 27th, 2020 17:45 Join Date: May 2017 Location: Lichfield	Thanks Baffler, fuel filter was my next port of call, I thought that would cause high fuel demand starvation but I'll change it anyway, it's well overdue! Any tips on how to get the EGR valve closed even with carbon build up? I couldn't get the valve out when I tried (hence unplugging it).

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)