Kangarooing when I put my foot down

[Rojo Habe]

OK, maybe "kangarooing" is too strong a word but that's how I can best describe what's happening. If I open the throttle more than about halfway, instead of a nice smooth acceleration the car starts to lurch slightly and I can hear the turbo cutting in and out. It's a not really a flutter, more of a regular on/off rythm about one-and-a-half times a second. Could this be a dodgy MAF sensor? In all other sircumstances it runs as smooth as you like, including a rock-solid idle at about 800rpm.

I'm not in the habit of flooring the throttle when the engine is stone cold but I tried it this morning and and it was fine. As soon as the engine starts to warm up (say after about half a mile), the problem appears, in any gear at any revs. It's also far less noticeable in cold weather (but still there).

'05 Mk1 Leon FR, no mods.

 

[blue51]

vagcom diagnosis (specialist rac london good, or people on here) + throttle body clean and reset

maf (in case any1 reading didne ken) - if confident then can disconnect maf drive for a short while and if prob goes away - hey presto!

last service? had air filter? clutch pedal switch can do this, again common and will be picked up on vagcom

some people on here find that using high ron (99) tesco or v-power : smoother, perkier, louder, more popping and it lasts longer and is less wearing internally!

anyone know if fully synthetic engine oil is worth an extra tenner?

ldubl

 

[Rojo Habe]

At this point I should state that I stopped understanding cars round about when plastic engine covers and Torx bolts started cropping up everywhere, but I'm willing to have a go, or at least learn enough that I'll know when my dealer is lying to me. So to deal with your points in order:


I'd gladly buy the vag-com software if I had the slightest clue where to plug my laptop in; my only other sensible option is to take it to a garage and get this checked so I thought I'd see what else could be checked by me first.

I'm not even 100% sure where the throttle is! My last car had a throttle cable, which was a bit of a giveaway. I'm assuming the big silver thing at the front is the inlet manifold, in which case I'd expect the throttle to be in there somewhere. Is it the flat round-topped bit near the big fat hose on the left (looked at from the front of the car). Sorry for the baby talk but I don't want to make assumptions. If I've got this right, is the that the MAF next to it, held in with a single Torx bolt and with a squarish connector on it?

Last service was last June; fourth annual in accordance with the service book. It's always been serviced by the same Seat dealer from new, so I assume they'll have changed the air filter last year (although that's the one invoice I can't find to verify it. Typical!). When I say fourth annual I mean 40,000 but it had only done 14,500, if that makes sense.

I've always run it exclusively on VPower.

Maybe I'll replace the air filter anyway, in the absence of last year's invoice, since it's listed in the service book as "additional work".Is it worth shelling out for a K&N instead of the standard Bosch?