Lurches in first gear....no idea as to why!!

[sirivor70]

Hi there. Have a query about my 87Westy 2.1l.

When I am in slow moving traffic, in first gear with my foot off the accelator, the van seems to lurch forward, slows and the lurches forward again. Not smooth movement if you know what I mean.

Bringing up the revs solves this, but should not have to. The engine is great, pulls like a train and idles lovely.

Any ideas?

Many thanks.

[dugcati]

hmm odd one that here's a few things off the top of my head...

How long have you had the van - if new to it/these could it be driving style (unlikely but it has happened in the past to others!)
air in clutch line?
clutch on way out?
engine/carb setup - does it run drive OK once moving or when not in gear (ie rev smoothly etc)

[Aidan]

Idle stab not kicking in or working properly engine should be able to hold 850rpm regardless of load in idle though heavy van/uphill/wear on clutch/tired box would all contribute to slightly lumpy running in circs described
take a look at wiki for idle stabiliser etc.
also how serviced is it ? good clean air filter, plugs, leads, cap, arm etc ?

[HarryMann]

Running rich at idle (for reasons Aidan has mentioned above ^)

Check T2 temp sensor and wiring as well..
Throttle stop adjustment can be critical
Is throttle cable smooth (or sticky)

Maybe exacerbated by broken or soft engine or g/box mounts

[sirivor70]

Thanks for the comments guys.

Have had the van three years now. At idle, engine is fine at 850....had to replace the idle control module unit a while back, as she was revving way to high, that that fixed it.

Service her regularly. Lots of new parts in there...Will sit happily at 65 all day long.

Only happens when I take my foot of the clutch and let her roll. No accelerator applied...Moves forward, but as I said, lurches.

Will look into what you have commented on and see what I can come up with.

[HarryMann]

A bit rich just off idle, creates a rhythmic go/not go cycle... is the exhaust black or the plugs dark or is it become juicy..

But it does sound very much like an engine or g/box mount has broken or delammed too.... lever them all about, and use Mk 1 eyeball > acutely!