Jump to content
peterdinosaur

VR6 Lurching when accelerating

Recommended Posts

Small problem with the Vr6 at the moment and really don't know where to start!

 

When I accelerate off the line the car goes, then bogs down, then it feels like a lurch wobbling the car and off it goes again.

 

Wondering if anyone has any ideas what may be causing this?

 

The car has new plugs, ht leads, coil pack and I have put a second hand ISV on it when another one had a problem.

 

Possible other symptoms could include a strong smell of fuel from the exhaust (possible over-fueling).

 

Any ideas would be great, if you can think why it is causing that smell as well that would be good, give me a task list. Also did run VAGCOM on it and it did not come up with any errors, but that was a few weeks ago before the current symptoms appeared, shall run that again this evening!

Share this post


Link to post
Share on other sites

What coilpack did you put on it, thats usually a sign of coilpack issues. Or the coolant sensors can lead to overfuelling.

Share this post


Link to post
Share on other sites

It is a Bosch/Saab Coilpack with the suitable wiring loom (was going to check that for shorts as well this evening) and I did change the coolant sensor about a month ago, can they go this quickly?!

Share this post


Link to post
Share on other sites

Shouldn't really go that quickly, i think you can look at the sensors in vagcom and check the readings the ecu is getting to determine if they are working correctly (i'm not totally sure how to do it though).

 

Am not sure if lambda sensor can cause similar symptoms. tbh i could just name lots of random sensors or parts which is what usually happens on the internet :lol: I seem to end up renewing everything and buying spares i don't really need.

Share this post


Link to post
Share on other sites

Was the plan I was going to go for, just hopeful someone had had the problem! I have already done some of the sensors and known causes, so Lambda next, could the MAF also be another culprit?

Share this post


Link to post
Share on other sites

So update on progress but not a solution yet:

 

I have fitted:

New MAF

New Camshaft Sensor

 

Also run the car with the lambda disconnected and then reconnected making near enough no difference.

As it still returns a code regarding the Lambda is it good to assume that this may be causing the issue.

 

Another point that has come to light is that it seems that 263 cams have been fitted to the engine, but no mention of a re-map, could this also be part of the equation as it does seem to be running very rich atm.

 

As the engine does sound very rattly I was beginning to contemplate just fitting a 2.8 bottom end and refurbishing the head and see where that lands me.

Share this post


Link to post
Share on other sites

Interestingly I've always had similar behaviour from my VR but only really when it's cold. Very similar to what you describe where you start to accelerate and it just feels as if it's trying to cut out almost, and then splutters back into life a bit again and then it's ok. Only really happens for the first 60 seconds of driving or so. Has done it for the last 4 years or so with no real hint of getting better or worse.

 

I too have the SP263's but an engine rebuild hasn't changed the behaviour so it must be something electrical - a sensor or something.

Share this post


Link to post
Share on other sites

Have you checked the condition of the various plugs on the engine loom?

Share this post


Link to post
Share on other sites

Mine seems to be all the time, but I also suspect the thermostat is broken, so not letting the engine heat up so is always a little cold........another problem I think.

 

I will have a good look round the loom, as some of the plugs look awful. Got some contact spray as well, can't hurt!

Share this post


Link to post
Share on other sites

Well enough of these cars need uprated headlamp looms due to voltage drop, I suspect the engine and ABS looms suffer exactly the same in this respect.

 

If it was mine I'd clear the codes, disconnect the battery for a few hours before a varied drive stopping and starting the engine several times before rescanning without interfering with anything.

 

You'll create a "ghost code" every time you unplug something whilst the engine is running throwing you off the scent. Check for a spark at all 6 plugs and a compression test would be a good move too

Share this post


Link to post
Share on other sites

Thanks for that plan Dox, I shall have a go at that over the next day or so, hopefully getting something a bit more concrete!

 

Shall also buy a compression tester which should get here for after the check, has had new plugs and leads very recently so would hope that is not the problem.....

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...