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View Full Version : Please Help Hesitation? What else could it be?



awilkir
17-08-2010, 10:06 AM
Hi All,

I am having a problem where the car hesitates (sometimes fairy violently) when the engine is under load accelerating up a hill/on motorway etc. It is most apparent between about 2000-3000 rpm. I first thought it was the MAF/Air flow sensor but I have changed it and no difference. There are no warning lights or messages on the dash.

It seems the problem only occurs when the engine is fully warmed up.

I am about to buy some cleaning stuff for the injectors, but other than that I'm out of ideas?

Its a 2005 A3 2.0 Tdi BKD engine, no mods.

Thanks
Ryan

Update

Injector cleaner in and fuel filter changer - fuel filter seems to have improved the situation but not cured completely, any help appreciated.

Thanks
Ryan

awilkir
23-08-2010, 04:22 PM
Looks like I'm off to vwrescue in the next week or so unless anyone has any ideas?

S1MON A3
23-08-2010, 04:35 PM
try give it a full clean out, change the oil, oil filter, fuel filter and air filter. Run the injector clean in there for a while, you could always clean your egr valve as well I did this today on mine and throttle felt slightly more responsive.

awilkir
27-08-2010, 12:23 PM
Cheers for the advice, time to stop changing everything i can identify! So its booked in next week. nothing seems to have made any difference to the problem.

Thanks
Ryan

mlockhart
04-09-2010, 06:14 PM
Hi Ryan - did you have any luck? I am having similar problems!!!

Malcolm

awilkir
06-09-2010, 02:19 PM
Hi
Still no luck unfortunately apparently there is an actuator/valve on the back of the turbo which you can stick some wd40 on to make sure its moving freely but I tried that (well someone who knows what they're doing) and its the same. The turbo is coming off for a look and maybe replacement.

baylissboy
06-09-2010, 09:52 PM
Have you checked the fuel pressure, sounds like the tandam pump to me!

awilkir
06-09-2010, 10:18 PM
It's had the diagnostics run and nothing came up but we suspected the fuel pump earlier when I changed the fuel filter the fuel in there was really black. Any way to check the pressure?

Cheers
Ryan

baylissboy
07-09-2010, 08:56 PM
There's an Allen headed bung on the back of the tandam pump, connect your pressure guage there, you should see 4ish bar at idle rising to 10+ bar at 3000rpm, bet yours doesn't make 6-7 bar!

awilkir
21-09-2010, 12:11 PM
Anyone have a Haynes manual pdf or know where I can get one? I have a tandem pump arriving Friday so I hope that this is going to sort it.

Also booked in for a service at Audi for £99 including a loan car for the day which I think is very good, anyone used this service?

Cheers
Ryan

awilkir
20-10-2010, 02:46 PM
Hi,

OK tandem pump changed, no difference (except I have less money!) also a couple of seals replaced around the intercooler pipes somewhere, Service was great but still no idea what is causing the problem? EGR valve is next target I think.

Ryan

roundwoodgarage
21-10-2010, 08:11 PM
you could do with finding someone who can go for a road test and record the live data, then analise it and see where the problem lies, fitting new parts one after another could cure the problem but at what cost. MAF sensor, fuel pump. service + filters etc!!

awilkir
22-10-2010, 11:40 AM
Hi does anyone know of a place to get this done? I'm near Wolverhampton.

Regards
Ryan

awilkir
04-01-2011, 11:20 PM
Hi All,

I still have this problem on the car, I had a fault code for the EGR valve which was replaced and the fault is gone but the hesitation remains. it only happens when the car is warm, one garage has had a look but couldn't pin it down. I think I need the real time data reading as suggested above. Any places in the west midlands that could do it?

Thanks again
Ryan

awilkir
14-02-2011, 11:13 AM
I believe I have sorted the problem. Finally! It was the injector loom harness, diagnosed with the help of this article -

http://www.vagoc.co.uk/vb/showthread.php?t=238

The car is a lot better, has more power and the mpg is back! No more hesitation or misfire.

Took a while to figure out but thanks to anyone that posted any help.

Cheers
Ryan