Judder after foot off foot on accerator

Post by **syncrodude** » 10 Aug 2008, 15:58

Hi

I have a Syncro with 1.9 petrol waterboxer i'm getting a judder after taking my foot off the accerator, then accerating from around 2200 rpm I get a slight judder, most of the time is ok , runs normal on motorway.
appears to be worst when coming up hill under load after a down hill.
I'm happy with the slight judder , but my other half is very nervious
got to get this done, need a holiday before I go nuts

Post by **Aidan** » 10 Aug 2008, 17:31

how's the vc and tyres ? Where's the clutch bite ?
TBH this could be any number of things, engine, transmission, mounts, prop, VC, clutch ? Going to have to narrow it down a bit.
How long have you ha dthe van, is this a new phenomena or longstanding ?

Post by **syncrodude** » 10 Aug 2008, 19:30

the judder is engine related like a misfire but at low revs high gear, i'm sure of that, suddenly started to do it. Did replace the plugs initially , but discovering the judder , put the older ones back in had improved but not completely. have sprayed the leads with WD, thinking of replacing the leads but they don't look very old.
Would a failing petrol pump do this?, Iv'e had this beast for a year now done about 120k miles , has a Pierburg carb.

Post by **KarlT** » 10 Aug 2008, 19:55

Sounds normal. You're just lugging the engine. Change down & get the revs up.

Post by **syncrodude** » 10 Aug 2008, 20:26

more after going down hill then judders a bit going uphill I still give it enough welly. I'm wondering why it used to cope with this load , but not now ?

Post by **Mick & Tracey** » 10 Aug 2008, 22:46

Sounds like clutch

Post by **syncrodude** » 11 Aug 2008, 08:14

Maybe I'm mislead ya all, saying it's judder , I think its engine misfire under load , gearbox and clutch renewed in the last 2 years. Tried spark plugs , going for new leads today.

Post by **Aidan** » 11 Aug 2008, 08:25

before buying new leads check the resistance of the old ones for balaence and in specness

Post by **syncrodude** » 18 Aug 2008, 15:46

I've just come back from hols. I found it was a loose air intake to the carb

Post by **Boltze** » 18 Aug 2008, 21:01

Be sure that your impact-heft is already on your cardan shaft and your cardan joints are okay.

On my 1985 I lost my impact-heft and my joints were broken, so I had heavy vibrations on different speed frequencys.

pictures of the old cardan shaft (298.278km):

[img:640:480]http://boltze.dyndns.org/pictures/vwbus ... 140015.JPG[/img]

[img:640:480]http://boltze.dyndns.org/pictures/vwbus ... 140016.JPG[/img]

By the way, the 1,9l carb engine is the best engine ever

Post by **syncrodude** » 19 Aug 2008, 09:40

That looks nasty , I've taken my prop off , don't always want the 4wd.

Post by **HarryMann** » 23 Aug 2008, 12:39

The whole engine transmission unit does have a natural vibe at a round those speeds, mostly experienced in top gear when pulling hard... also check your engine mounts individually for delamination/softness and front transaxle ones.

The inlet to the carb itself is not that critical I would have thought, but if thats fixed it, so be it... is the air filter clean?

Post by **syncrodude** » 23 Aug 2008, 13:07

Yes I had recently replaced the air filter , I assume the leak had made the mixture a bit leaner than it should be

Post by **HarryMann** » 23 Aug 2008, 13:14

Yes, the point being that with a new air filter in shouldn't make it much weaker at all, so you now know its a bit marginal firing that mixture