Re: Shudder and Hesitation
As you say 25 k on the filter is pretty far, best change it first.
Re: Shudder and Hesitation
After filter,the next possibility could be a failing injector harness.
Re: Shudder and Hesitation
Have you checked the lift pump is working correctly? You should be able to hear it prime when you turn on the ignition (it's under the rear seat).
Re: Shudder and Hesitation
changing Air & Diesel filter is a must
Diesels are fairly basic engines and just need these changed every 20,000 miles in my humble opinion
I would let the Fault develop, is the cheapest option; annoying as it is.
I suspect the EGR valve, but without a fault code your goosed, just don't go swapping parts until you find out. However checking the wiring harness is free
Re: Shudder and Hesitation
I should also have mentioned the intake throttle / antishudder flap, I've had to replace two of these on 1.9 pd engines, the first engine had symptoms similar to yours, the second one threw an EML light and code. They seem to be fairly common failures, first I had was around 100k, next one was on 70 odd k engines.
Re: Shudder and Hesitation
Thanks for your replies. I can hear the lift pump prime. Took the rear seat out and I can hear it.
Had a mechanic out today to change the fuel filter. Pretty black. He checked for fault codes - none. The same problem on the way home. As usual it takes up to 1/4 mile for it to first happen.
I suppose it could be an intermittent or weak lift pump. Is there any filtering on the tank pick up?
Would a clogged EGR not show a fault code? Are there any checks I can do?
I have been trying to pay attention to what is going on when it happens. It's fine at idle. It hasn't cut out yet. Wider throttle openings seem to be ok. It's seems to be low throttle openings when it happens. With the new filter I can floor the throttle when the problem happens and it clears. Although this isn't practical in a line of traffic.
Could be a faulty TPS ? But wouldn't that show a fault code?
Cheers
Paul
Re: Shudder and Hesitation
If you have access to VCDS you could take logs (as you're driving, to replicate the fault conditions) of the various fuel/injector measuring blocks and possibly their respective control systems (my VCDS knowledge is limited), which might help in the fault finding process.
Re: Shudder and Hesitation
Quote:
Originally Posted by
tditaff
If you have access to VCDS you could take logs (as you're driving, to replicate the fault conditions) of the various fuel/injector measuring blocks and possibly their respective control systems (my VCDS knowledge is limited), which might help in the fault finding process.
A suggestion as to what diagnostic kit to try would be gratefully received. Don't want to pay a fortune for something that I use once or won't see and log the live data. Willing to pay for the time to any one who has the the right kit that could help. Bit of a loss at the moment and it's getting challenging to drive.
Thanks
Paul
Re: Shudder and Hesitation
Found a local VW specialist. They were pretty sure it was a failing injector harness. They replaced it today and the fault is still there. Bugger! They are now scratching their heads. They describe it as sudden and quite dramatic.
They have driven it with a reader plugged in. No fault codes. They see like it's a total shut off. Very intermittent. Like something is turning off and back on but not affecting idle.
They are going to replace the ECU relay next as it's the next least cost option. If that doesn't work it's a relay in the vacuum unit (which means replacing the whole unit -not cheap). This is getting expensive! Could be a dying ECU!
Paul.