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Re: Engine revs slow to drop down

Posted: 14 Aug 2014, 09:46
by killerme
I thought this might have been the clutch but it definitely isn't the clutch. When I put it out of gear it still races when it is really bad. I'm working in Iraq at the moment and one of the mechanics here thought that it could be the waste gate valve of the turbo. If this was occasionally sticking in the closed position it might give these symptoms? Can anyone add to this or reject it as a possible diagnosis? is it possible that this would only stick when the engine heats up, and would be worse after traveling high speeds (well 70) along a motorway for an hour or so.

Re: Engine revs slow to drop down

Posted: 14 Aug 2014, 11:51
by kenkelso
I had a similar problem once and did a lot of head scratching before I found that the whole injector pump was loose and vibrating. Check that all the bolts are tight, one of mine was missing!

KenK

Re: Engine revs slow to drop down

Posted: 15 Aug 2014, 08:09
by killerme
thanks kenkelso - I'll definitely have a go at that

Re: Engine revs slow to drop down

Posted: 19 Oct 2014, 06:36
by killerme
An american friend at work has suggested that the wastegate might be sticking and not allowing the pressure to drop. If it is sooted up it could stick in the closed position when the engine heats up. This would explain why it is worse when travelling on the motorway. After about 15-20 minutes it is really bad because it is in the closed position for a while - but when I travel along country roads - it is opening and closing all the time and therefore doesn't stick. Any diesel specialists out there agree?

Second question - where the hell is the wastegate - somewhere on the turbo, yes?

Re: Engine revs slow to drop down

Posted: 16 Feb 2015, 20:59
by nordberg
I'm having this problem (revs not dropping when changing gear). Not the throttle cable. Any help here would be much appreciated.... :)

Re: Engine revs slow to drop down

Posted: 25 Feb 2015, 22:43
by manxblade
I had this problem after replacing injectors what I did was turn the fuel enrichment screw back a quarter of a turn and it now works fine

Re: Engine revs slow to drop down

Posted: 26 Feb 2015, 06:24
by killerme
this sounds interesting - is there any chance you could point me to the fuel enrichment screw? Even a vague pointer would be enough "its on the ...." cheers manxblade (apologies for my ignorance - I still haven't got to terms with a diesel engine yet)

Re: Engine revs slow to drop down

Posted: 26 Feb 2015, 09:42
by nordberg
killerme wrote:this sounds interesting - is there any chance you could point me to the fuel enrichment screw? Even a vague pointer would be enough "its on the ...." cheers manxblade (apologies for my ignorance - I still haven't got to terms with a diesel engine yet)
Can I assume that your still having problems then killerme ? :roll:

Re: Engine revs slow to drop down

Posted: 27 Feb 2015, 21:44
by manxblade
killerme wrote:this sounds interesting - is there any chance you could point me to the fuel enrichment screw? Even a vague pointer would be enough "its on the ...." cheers manxblade (apologies for my ignorance - I still haven't got to terms with a diesel engine yet)

Video here hope it works for you turn it anti clockwise for less fuel and only do a quarter of a turn at a time
https://www.google.co.uk/url?sa=t&sourc ... odCWilaTZQ" onclick="window.open(this.href);return false;

Re: Engine revs slow to drop down

Posted: 03 Mar 2015, 11:20
by HarryMann
a facebook thread on this subject active.

Re: Engine revs slow to drop down

Posted: 03 Mar 2015, 11:22
by HarryMann
on VW T25 club. Andy Burrows

Re: Engine revs slow to drop down

Posted: 03 Mar 2015, 12:06
by nordberg
I think you will find that's my thread :D . Although I understand the confusion with my username on here :?

Re: Engine revs slow to drop down

Posted: 03 Mar 2015, 13:18
by HarryMann
Ah! thought that a possibility :)

Re: Engine revs slow to drop down

Posted: 08 Mar 2015, 15:29
by killerme
Yes Manx - still a problem though not as bad. Still keeping my options open. Been working abroad but home now for all summer so can concentrate on the REAL issues!

Re: Engine revs slow to drop down

Posted: 07 Apr 2015, 09:50
by nordberg
Hi there,
Just been away for a couple of days in the van and it may be a little early to jump to any conclusions about weather or not my issue is no longer an issue any more but it seemed to be behaving itself now. I know this isn't my thread but the only thing I have done is replaced the high pressure injector lines. Bizarre :roll: