I Love my new, and 1st VR4!!

[davesleg]

I have wanted a Legnum for a while, and finally, i have taken the plunge and bought my 1st one. The car is a 1996 Legnum, and the car is everything, and more, that i was expecting! Great car! I do have aproblem with it though and really would appreciate some advise. The car pulls like a train when i put my foot down to about 3/4 throttle, but if i floor the accelerator pedal, the car just coughs and splutters and looses power. Can anyone help please?

[Ryan]

*yawn* nothing to see here.

[ILLEGAL]

new sparkplug and/or fuel filter time ?? i dont see anything wrong in the engine bay.. AFM will take into account the intake air temp is warm and lean the fuel accordingly. the problem is a hard one to fix via internet.

[elnevio]

My money would be on a small boost leak somewhere - possibly the DV leaking under pressure. I agree with Richard insofar as the lack of a snorkel not being particularly detrimental, and certainly not to the extent that has been described. (Sorry as well, Ryan! )

[Ryan]

Well I guess I have been told. Best take the expert's advice

[Nick Mann]

Do you get black smoke out of the exhaust when it coughs? Do you know if there is a boost controller in there?

[Ryan]

Do you know if there is a boost controller in there?

^ That looks quite similar to the one i have.

[ILLEGAL]

Well I guess I have been told.

not at all... every little comment helps us all. because the car will benifit with all you mentioned above.

[davesleg]

Yes there is a boost controller fitted, and yes sometimes it produces a bit of black smoke when it coughs. I have bought a new boost controller from ebay, as the one on there now, has a pipe which has no hose connected to it and i was suspecting this to be a potential problem, hopefully the new one arrives today so i can fit it and see if that solves the problem. Should there be any need to adjust the nut on the end of the dump valve?

[davesleg]

A couple of pics of the boost controller, that open end pipe isnt right right?!

[mike74]

As a trial, I'd suggest disconnecting the bleed valve & revert to standard boost control for a while to see if it behaves itself. If it clears itself then at least you know thats more than likely the culprit

[chris g]

I'd expect car to play up if snorkel and air filter had been removed...

[Wobble]

by the looks of it that boost controler is set up ok.

is there a boost gauge in the car?

may be woth turning it down or even removing to standard condition. you may well be hitting fuel cut if its turned up to much or is faulty

[aboo]

I'n not sure when it comes to these MBC's but it looks like its plumbed in to the right hose but as Dave said is there a boost gauge & if so what's it reading? If not I'd disconnect the MBC, put back to factory setting & fit a gauge before fitting another MBC.

[chris g]

And I have a default position of mistrusting aftermarket BOVs...

Revert to std and see how car runs...

[davesleg]

My new boost control valve came today, fitted it, and the coughing has disapeared with the valve turned right down, not much boost in this position, but slowly increasing now, getting better and better. What should my boost gauge read at full throttle plz? Gotta get it right soon, just been royaly embarresed by a 350z! Grrrrrrrrrrr!!!!!!!!! lol! Thanks all for the great help and advice.

[aboo]

If your hitting 13/13.5psi I would say that was safe enough for everyday use.

[Davezj]

are you sure the cough you are describing is not fuel cut. all power disapears and you lift off the accelerator in panic mode and it does this every time you floor it.
what happens if you keep you foot down once the power goes, does it come back and then go again, if so i would suggest fuel cut.

it just an alternative suggestion

[Nick Mann]

I'd be thinking fuel cut too - that's why I asked about a boost controller.

[davesleg]

Many thanks everyone for the great advice, it was deffo overboosting and hitting the fuel cut off, boost is now set at 13psi and the car is running real nice, now,, where is that nissan 350z that i lost to cos of fuel cut off??!!!!!!!!