Hello.

Since I've owned it, my V8V 4.7 has occasionally cut-out when accelerating. It only does this for a half second then comes back as normal.

The effect is like jabbing the brakes. My passengers are starting to think I don't know how to drive it!

I've read a few things that suggest reflashing the ECM or changing the fuel tank but before I give it to my dealer, I'd like to do a bit more diagnosing.

Anyone seen this before or got any pointers?

I'm going to see if there are any codes stored now.

Thanks!

 

only while accelerating not while trying to shift right?

 

Yes. Only really in 1st or 2nd, too. Unless it's just less noticeable in higher gears.

It's not necessarily when I'm accelerating hard, either. Can happen when driving "normally".

Haven't had a chance to check for codes yet, but I'm fully expecting there to be nothing recorded.

 

my problem was i couldnt shift at redline. i would have to let my rpms drop before i could shift again. it was a faulty clutch position switch and i replaced my clutch as well.

 

I was wondering if it was a clutch switch related problem. I know on some cars the ECU will pull the revs if you press the clutch, but I didn't think the Vantage was one.

For your shifting problem, it sounds more like a hydraulic actuator problem as the Audi RS4 are prone to suffer from. Did you ever get a 100% satisfying diagnosis on your problem after autopsy?

 

Can you describe this more(guide me through what your doing to make the concern happen)..
Also:
What trans do you have, a normal 6-speed stick shift or ASM?
Has the emissions light ever come on when this concern happens?
Does this always only happen at the same RPM/gears/speed?
Have you past a couple tanks of fuel through, or still on the same fuel fill?

 

It's a stick shift and the emissions light has never come on since I've owned the car.

I only put 98RON in and use various suppliers, so I don't think it's the fuel.

It seems only ever to happen in 1st or 2nd and not generally under WOT (IIRC). Generally it happens after some slowish cruising followed by a slowdown (or stop) and then happens when accelerating away, like at a junction for example. Not ideal. Actually, maybe it only happens in 1st, thinking about it.

It doesn't happen that often. It's happened maybe 10 times in a couple of thousand miles. I am now trying to make an effort to remember the exact circumstances it happens in.

 

Just checked. No DTC stored at all.

 

what became the verdict/outcome?

Was this remedied...

 

Um, no. The dealer couldn't find anything wrong with it, and it happens so infrequently that I kind of forgot all about it. Haven't driven the car for a while, but I will soon and see if it happens again.

Once thing the dealer did say was that it was a good idea to get the ECU to "relearn". Not sure what it's learning, but the procedure is apparently to (IIRC) get up to above 80mph in top gear and then coast down to about 50. 3 times, I think.

I know, sounds implausible, doesn't it? Still, this guy knows his stuff.

I never got round to doing it because when it occurs to me to try, the road conditions are never right for that kind of larking around.

Why, you having the same issue?

 

I just picked up a 2012 V8 Vantage 2 months ago. I noticed on the servicing documents the original owner had complaints of engine hesitation almost like the car went into sudden braking.

after >500 miles of driving I started to notice this hesitation under hard acceleration. Very annoying since its a frightening feeling to get hard hesitation under speed.

After >3000 miles of harddriving (dealership suggested to drive it hard to have the computer learn all possible parameters). The problem went away for good...until the battery died as it was at the shop getting some vinyl work done.

Upon driving away (after the battery was recharged) the hesitations came back...bu this time I was driving under acceleration going into a highway on-ramp and the engine cut out. This has only happened once..but extremely dangerous.

I plan on doing a spirited drive this weekend to get the computer to relearn what I had done..but this is akin to everyone else's complaints/concerns.

 

Need more info. Read through the FAQ sticky to see if anything there is the cause (a few links in there are relevant to your symptoms).

Here's the coast down procedure ref'd above.
https://www.6speedonline.com/forums/...rrections.html

Check the fuel vapor recirc hose (FAQ)

Check the throttle body (might need to be cleaned)

 

Check to make sure the rubber snorkel that connects to the intake manifold is secure. I had a similar problem which was attributed to this. The MAF was triggering limp mode...