Hi everyone, Pretty hard to describe. But on my VLT under acceleration at times, usually from standstill or lower speeds, power delivery seems to be laggy or nothing there. Only happens for about 5 - 10 seconds after you put the foot on the pedal (about 1/2 throttle to full throttle) After the initial hesitation, away it'l go no worries. Another descrption I could give it is, like its hitting a wall. And then all of a sudden it'll go. The car is a VL SL Turbo conversion - With full factory and stock A8 engine running gear from a donor genuine VL Turbo SL. When I got the donor car they were running it off a non turbo manual ECU. The Turbo ECU was there as well but not used. When I did the changeover I put the original Turbo ECU back on. Car seems to run fine with it. But there may be a problem with that ECU. Why else would they have run an NA ECU? Also have a boost gauge, and Im only getting 5 psi. I thought stock they were 6 -7 psi?

Is your car auto? If so that's the problem. ---------- Post added 14-01-13 at 09:15 ---------- All my vl's with auto's have done the same thing after giving them a hard time, its like when you put your foot down its really slugish in first gear but then drives normal. Also is your boost gauge running off your Plenum cause that's wear it should be. When you change from an NA ecu over to a TURBO ecu you should notice straight away that the car is running and sounding more angry! If it isn't you might have a chipped ecu. Have you pulled the cover off the ecu to check if it has the detonation board in it?

Its a manual. 5 Speed MX7 I have not opened up ECU to have a look inside. Boost gauge is connected to plenum.

No other ideas anyone? Thinking about getting another Turbo manual ECU to try?

Hitting a brick wall in acceleration sounds like a intank fuel pump problem. Had that happen to me with a few VL's I've owned. Everything is sweet if you don't flatten the pedal but it was OK if you slowly put the accelerator down in increments. It use to happen around 2,000rpm to 3,000rpm. Very annoying!!! Also another thing. A standard VL turbo fuel regulator is a rising rate where as the NA regulator is just a normal fuel regulator.

Replaced intank pump with a new one and also replaced fuel return hose to swirl pot. Fuel pressure reg is the stock VL turbo item.