Engine revs slow to drop down

Big lumps of metals and spanners. Including servicing and fluids.

Moderators: User administrators, Moderators

killerme
Registered user
Posts: 145
Joined: 04 Mar 2012, 13:17
80-90 Mem No: 10772
Location: Holywood Northern Ireland

Re: Engine revs slow to drop down

Post 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.

kenkelso
Registered user
Posts: 41
Joined: 22 Mar 2011, 11:29
80-90 Mem No: 9404
Location: Cambridgeshire

Re: Engine revs slow to drop down

Post 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
1990 Westy Atlantic Pop Top 1.6TD JX

killerme
Registered user
Posts: 145
Joined: 04 Mar 2012, 13:17
80-90 Mem No: 10772
Location: Holywood Northern Ireland

Re: Engine revs slow to drop down

Post by killerme »

thanks kenkelso - I'll definitely have a go at that

killerme
Registered user
Posts: 145
Joined: 04 Mar 2012, 13:17
80-90 Mem No: 10772
Location: Holywood Northern Ireland

Re: Engine revs slow to drop down

Post 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?

User avatar
nordberg
Registered user
Posts: 471
Joined: 14 Sep 2014, 12:32
80-90 Mem No: 14064
Location: Derby

Re: Engine revs slow to drop down

Post by nordberg »

I'm having this problem (revs not dropping when changing gear). Not the throttle cable. Any help here would be much appreciated.... :)
Red Atlantic pop top (1.9AAZ engine)http://www.daswolfgang.com

User avatar
manxblade
Registered user
Posts: 118
Joined: 11 Aug 2013, 06:41
80-90 Mem No: 12707
Location: Cheshire

Re: Engine revs slow to drop down

Post 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

killerme
Registered user
Posts: 145
Joined: 04 Mar 2012, 13:17
80-90 Mem No: 10772
Location: Holywood Northern Ireland

Re: Engine revs slow to drop down

Post 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)

User avatar
nordberg
Registered user
Posts: 471
Joined: 14 Sep 2014, 12:32
80-90 Mem No: 14064
Location: Derby

Re: Engine revs slow to drop down

Post 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:
Red Atlantic pop top (1.9AAZ engine)http://www.daswolfgang.com

User avatar
manxblade
Registered user
Posts: 118
Joined: 11 Aug 2013, 06:41
80-90 Mem No: 12707
Location: Cheshire

Re: Engine revs slow to drop down

Post 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;

User avatar
HarryMann
Admin/Mod
Posts: 9609
Joined: 30 Sep 2005, 11:40
80-90 Mem No: 379
Location: Herts, UK

Re: Engine revs slow to drop down

Post by HarryMann »

a facebook thread on this subject active.

The 80-90 Tech Wikipedia Your 1st port of call :idea

1.9TD Syncro Doka / Syncro Kastenwagen / 16" Kombi Camper
Syncronaut No. 1

User avatar
HarryMann
Admin/Mod
Posts: 9609
Joined: 30 Sep 2005, 11:40
80-90 Mem No: 379
Location: Herts, UK

Re: Engine revs slow to drop down

Post by HarryMann »

on VW T25 club. Andy Burrows

The 80-90 Tech Wikipedia Your 1st port of call :idea

1.9TD Syncro Doka / Syncro Kastenwagen / 16" Kombi Camper
Syncronaut No. 1

User avatar
nordberg
Registered user
Posts: 471
Joined: 14 Sep 2014, 12:32
80-90 Mem No: 14064
Location: Derby

Re: Engine revs slow to drop down

Post by nordberg »

I think you will find that's my thread :D . Although I understand the confusion with my username on here :?
Red Atlantic pop top (1.9AAZ engine)http://www.daswolfgang.com

User avatar
HarryMann
Admin/Mod
Posts: 9609
Joined: 30 Sep 2005, 11:40
80-90 Mem No: 379
Location: Herts, UK

Re: Engine revs slow to drop down

Post by HarryMann »

Ah! thought that a possibility :)

The 80-90 Tech Wikipedia Your 1st port of call :idea

1.9TD Syncro Doka / Syncro Kastenwagen / 16" Kombi Camper
Syncronaut No. 1

killerme
Registered user
Posts: 145
Joined: 04 Mar 2012, 13:17
80-90 Mem No: 10772
Location: Holywood Northern Ireland

Re: Engine revs slow to drop down

Post 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!

User avatar
nordberg
Registered user
Posts: 471
Joined: 14 Sep 2014, 12:32
80-90 Mem No: 14064
Location: Derby

Re: Engine revs slow to drop down

Post 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:
Red Atlantic pop top (1.9AAZ engine)http://www.daswolfgang.com

Post Reply