zarpoxx

Hello,

I am going to be crazy with my new problem: I have a 965 3.3 MY 91 with option X33 (or turbo S no lightweith) with 355 hp. It is a rare option, the only thing that change between mine and stock is a more agressive camshafts (1.1 º) and two things more.

My main mods are (actually fixed): cat bypass from GHL, KN filter and 1 bar spring. The rest is stock.

The problem:

Until 15 days ago, the car was awensome, starts boost at 2.600 r.p.m (more or less) in ALL gears.

But from 7 days ago, without an explication (stayed in my garage all time), the car seems "heavy" to spool. Now I have no boost until 4.000 rpm has reached in first gear, and 3.500 rpm in second gear.

In the rest of the gears, seems to be normal (boost at 2.600 r.p.m more or less).

Last sunday I dismantled the CBV (compresor bypass valve, the little black valve (from bosch)) because in the adrian´s book this is a possible fail. But when I took this valve, all seems good (no visual leaks, and the internal spring seems to be OK, it is hard)


What happens? Please I want some advice, because here in spain my car is a very very rare model and I dont want to spend my time and money changing pieces in good condition.

Thank you.

P.D: I posted two pictures only for enterteiment . My car, and a pursuit between my car and a yellow gallardo to

http://img114.imageshack.us/img114/939/192clcz0.jpg

http://img247.imageshack.us/img247/3659/458zhaq7.jpg

porshah

Don't have any advice on the turbo lag, but nice color car.

911addict

Zarpoxx,
Sorry to hear your car is running rough. Mine too, very strange.
I love that 2nd pic!
regards,
Mark

nathanUK '81 930 G50

Is the exhaust blowing/leaking ?
Air leak ?
Intercooler rubber rings ?
Wastegate leaking ?

ghhally

A trick I always use to search for leaks, is using starter spray.
Let the motor run and spray on those suspect areas. If the engine rpm raises, you've got air leaking.

Rgds,

Geert

nathanUK '81 930 G50

For intake leaks.

ghhally

To quick!
Your correct Nathan, only intake.

Rgds,

schnele

It sounds like the intercooler hose has come loose or has a leak, check fittings

fritz k.

hi,

nice car..

also my first impression was, the problem is relating to a pressure leak. somewhat strange is, that it seems to appear only in 1. and 2. gear...

to check the shut-off valve you need a small vacuum pump, which has to be attached to the upper thin connection pipe. the membrane should rise under vacuum and hold steadily that upper position. if it don´t rises or slowly drops the valve needs to be replaced.

fritz

nathanUK '81 930 G50

I think also you can use Propane. Search for it on here if you wanted to use it first though just in case I got it wrong...

Miguel

Ola,I had a similar problem, the car, a 3.3, showing an awfull lag and stalling behaviour before boosting.Turned out the cat needed cleaning and something was faulty with the lambda sensor..
Anyway, that i s what the mechanic told me, and that is what he did and the car is fantastic, now...
just my two cents, as they say..

Miguel

38D

Sounds like the world famous intercooler o-ring

zarpoxx

Thanks at all!!

I will try next weekend to check fittings.

I will tell you what it is wrong (if I be able to see where is the "problem").

Thanks again!

P.D: I will cross my fingers...

zarpoxx

Hi!!!

First, I am stupid.

The problem was in the boost pressure regulator (valve in the intercooler, with a red plastic). This valve provide information in bars to the tachometer (display in bars), and here is the problem.

I am very stupid because I not hearded when the turbo spools, (you Know, when you heard psssss!) I only see at the tachometer (display), and the lag is in this valve (boost pressure regulator).

So, this lag was more or less aprox 1.5 seg. When you are at 1 bar, the valve sends this information with this lag (aprox 1.5 seg), so this is why in first and second gear "seems" that began to spools later (because in this gears, is very quickly the needle in the tachometer).

In the rest of the gears, all seems ok because the needle was slower.

The good notice ( i hope), is this: I belive that I know how could resolve the common problem with the display that only shows 0.7 bar.

I belive that we will do is change this valve (boost pressure regulator, valve with a red plastic cap in the intercooler) and fix a new one from the 930!!! (this valve is able to show 1 bar and more!).

Next week (i hope), I will try with this experiment. I promise you that I will write what happens

Thanks all again. This is a amazing forum!

Bye!

P.D: I hope that you could understand my very bad english....

911addict

zarpoxx,
Glad to hear your car is running well.
Very interested to hear whether this 930 valve will show more than .7 on the gauge.