On that note, why is this TB half price? http://www.ebay.com/itm/BRAND-NEW-GE...ddc4c2&vxp=mtr

 

Just sharing personal experience but my car was doing this and I bought a cheap maf on ebay. Did not fix the issue so I was stumped. Finally got car to dealer to check out and they recommended a new Porsche maf. I know I know they wanted like over 700 bucks for this thing and they seem to be around for like 150-275 BUT new Porsche maf DID fix the car. Have driven it several times since and no problems at all. Just sharing my experience. Some have used the cheap mafs with no problem. The one I first bought did not work for me and the only thing the dealer did after checking everything out was to replace the maf with an original Porsche one. Good luck!

 

I'm interested to see what you find out on this. My car seems to 'lug' at low speeds. And I suspect things are very tight in the throttle area.

 

The MAFs I've tried have been Porsche ones. I've also checked the plugs, the were fine, replaced the Beru coilpacks with Bosch ones. Checked all hoses around the turbos and intercoolers, everything looked fine, but the hesitation remains.

Any other ideas?

 

Pre turbo intake leak , header or exhaust leak , se ideas.
Did u do a high boost pressure test ?

 

Subscribed.

 

Checked for leaks at high pressure, nothing major, held pressure for almost a minute. Pre-turbo intake is difficult to check as most piping is well hidden. Also, are you sure it's related?

Let me repeat something from the first post:
The problem is a slight hesitation when getting back on the throttle at low rpms that's been getting progressively worse. Most noticeable in 1st and 2nd gear. I apply a bit more throttle to accelerate but the car seems to cut for half a second before pulling its **** together and giving me some power. It happens at low rpms, so I guess it's not boost related.

It always happen between idle and 2000 rpm. Everything is fine above 2000. Also, I've noticed that when I get back on the throttle the oil pressure dips for half a second. Is that normal or perhaps related to this?

 

Fuel pressure/ bad injector? Sounds like MAF or throttle body but I see these have already been discussed.

 

I've got a 5 bar FPR, rest of fuel system stock.
But shouldn't a pressure or injector problem show itself at higher RPMs, this occurs at very low revs with low load. Pretty sure MAF is excluded, throttle body is another story. It's a bit of play in the gears but it has been cleaned and I think I might have noticed a slight improvement, but that might just be in my mind. Not sure how much play is acceptable, but it costs 700 usd+ to make sure. Does Durametric log fuel pressure? I've got Dura6 so I can log whatever you guys need to eliminate things.

 

I have cured many idle problems with a good injector/fuel cleaner. I know I will hear arguments but have helped many a friend cars with that advice. My buddy spent a small fortune having his 928s4 diagnosed and was dirty injectors throttled body.

 

Have you checked Vario Cam solenoid bracket?

 

Yes. When I replaced the coilpacks I also checked and replaced both brackets. The old ones were fine.

To recap:
Did pressure test - ok
Replaced MAF three times, got new plugs, new coilpacks, new throttle body, new plenum, new variocam solenoid brackets, tried with both tune (EPL) and stock setup. Tried enganging the various variocam features while idling, responds as it should.

Seems to be getting progressively worse, noticeably more the last few months. No fault codes.

Still wonder about the dip in oil pressure as I re-apply throttle after coasting in gear at low rpms. Is that normal or indicative of a problem, possibly with variocam?

 

How is your idle?? Did you test your variocam solenoids via the durametric cable?

You can have a solenoid stuck in high, instead of it dropping back to low for idle. You would see this on partial throttle without a doubt. Run like a beast at WOT since its stuck in HIGH but ****ty partial throttle because of changing from idle to load since its not dropping back to low. I would test those solenoids.

 

My idle is normal as always, actuating the variocam solenoids with Durametric results in a variation in RPM so I guess they're working. If there is a more scientific way to check if it works correctly, I'd be happy to try it.

 

You can check the solenoids individually by running 12volts to each while the car is running to throw them into high vs low.

Considering you did coils and plugs it starts to make it seem like a fuel issue possibly also. Have you ever ran e85? or strictly just pump gas?

Did you run any misfire diagnostic on the car at all? Did all the plugs look good when u pulled them? Sorry to hear about your troubles. trust me you are not alone.

What are your O2's reading at idle and partial throttle and wot?