Almost stalling at low revs

[markos]

hi, as most of you already know i'm not a mechanic... i just enjoy driving my gti and know very little about the mechanics of it although i'm trying to learn as much as possible to increase the longevity of my car!

it's developed a bit of a fault now where if i'm queuing i need to give it loads of revs to stop it from stalling... is that a timing issue or do these cars not like sitting still!? seemed to be ok a few weeks ago i think but could just be something i've noticed more recently. also, i notice that the engine has a certain "diesel noise" about it when ticking over. is that normal?

any help or suggestions would be much appreciate!

[markos]

also, to add to that which may or may not be connected... since i got the powervalve downpipe and sports cat installed last week i've noticed a bit of backfiring on deceleration. could that be a timing thing too?

and to add to that there's a bit of a rattle coming from the engine bay when sitting idle and revving a bit. i think this might all be linked somehow.

the car just feels a bit.... well fragile i guess. it's almost like something isn't quite right

[th3_f15t]

Right, power issues are normally linked to problems with air delivery to the engine. First port of call, check your air intake system and make sure the flow of air isn't blocked and that the sensors are plugged in and working (fault scans required).

Next, check boost pipes from and to the intercooler, these are prone to failure also.

DV diagnostic is a must if you've not done this already.

With your downpipe, I assume you've had a re-map to help the ECU cope with the much increased rate of gas flow from the engine?

As for rattles and tractor sounding engines, there's possible some wear on your cam chain but replacing it is costly and risky so advise to leave it unless it really does sound like a diesel even with the bonnet closed.

[markos]

Right, power issues are normally linked to problems with air delivery to the engine. First port of call, check your air intake system and make sure the flow of air isn't blocked and that the sensors are plugged in and working (fault scans required).

Next, check boost pipes from and to the intercooler, these are prone to failure also.

DV diagnostic is a must if you've not done this already.

With your downpipe, I assume you've had a re-map to help the ECU cope with the much increased rate of gas flow from the engine?

As for rattles and tractor sounding engines, there's possible some wear on your cam chain but replacing it is costly and risky so advise to leave it unless it really does sound like a diesel even with the bonnet closed.

thanks mate, all good advice there. i'm actually getting a dv+ from gfb fitted this week so that might help out with extra boost.

turns out the rattle was actually from the air intake itself! was really annoying but managed to hunt down the source, it's just not a great fit and it was vibrating at certain revs i guess. might investigate getting that upgraded at some point.

i spoke with r-tech about the new downpipe, they did a stage 1 last year and nick didn't seem to think it would need tweaking since the new downpipe. i'm trying to get it booked in anyway just to be sure!

i heard that the tractor noise is pretty common in the fsi engine so i guess that's just something i'll have to get used to!

thanks again for the help though mate, i painted the calipers this weekend so it's coming along nicely. cosmetically it's almost there, apart from getting the front wing de-keyed!

just the dv+ and the revo torque mount to go and then i think that's it for mods (for now anyway  )

[th3_f15t]

I run a GFB DV+, I love it and the way it changes the characteristics of the engine under acceleration. As for the air intake, if you opt for a full cold air induction (CAI) kit, you'll gain power at the peak of your engine but loose torque at the lower end of the RPM. I personally run an APR carbon scoop (looks good, does nothing to improve flow!) and a K&N panel filter, although I'd recommend a Pipercross (or any dry air filter, not oiled).

I'm pretty sure you need to tweak a map when fitting a downpipe and sports cat (definitely for a de-cat) as the sensors go nuts due to the huge difference from acceptable "stock" values. A stage 2 remap normally always goes hand-on-hand with a new downpipe and cat. I'm not doubting R-Tech as I've read many good things, but I have also read bad things (true of any garage/tuning shop though).

[markos]

spoken with r tech again today, i do still rate them if anyone needs mapping 

they said that the current stage 1 remap will be fine with the new downpipe and won't need tweaking just for that, if i wanted to go to 2 then yes. but it will be fine on it's own.

interesting to find out that they don't rate the gfb dv+ though, in fact nick won't remap with one fitted so not sure what the issue is there. g revision is what they recommend.

i'm probably an idiot for going against them, but after hearing so many good things from loads of other people and also the fact the oem could split at any time i'm still going to get it fitted it this week 

[th3_f15t]

I have ready stories of them suffering boost leak similar to the OEM ones when they split, but GFB did issue a revised part and also exchanged the parts responsible to customers for free. R-Tech can be quite arrogant/stubborn from what I've read over a few forums, but compare that to the many, many happy customers (and considering I've not used them) I can't form an opinion.

[markos]

fitted the gfb dv+ tonight and that's made a difference. just feels a lot sharper now and there's more consistent boost through the gears. very happy with that little mod, good on those aussies