Phil964T

Hey Folks,
i'm new on this board. I've read a lot of stuff before posting and I would like to say Congratulations for this nice Forum.

I've used the search fonction but I really don't know what is the term of the issue I seem to have with my 964, so it's hard to find what I'm looking for.


What I got is a 964 Turbo 92' STOCK with 57 000miles on it. This morning, I was at a red light going on the highway when I gave full throttel in first gear. At ~ 4000 RPM, the car start to shake really hard and the RPM was block at 4000rpm. I've could read on the Boost Controler 0.7BAR wich seems normal to me. Then I shift the second gear, the car do the same thing but at ~ 3000rpm, Shake and couldn't accelerate. So I put the car in Neutral and tryed to rev it, the RPM blocked at ~15000. I pull over. Let the car idle for maybe 30 secondes. The idle wasn't that smooth. So I gave a couple of Rev on the engine, and tried to accelerate in 1st gear. Everything was ok. Like nothing happened... The car already made that last year. It was the Intercooler tubing that was pierce near the collar. I checked but everything seems fine. I haven't seen black oil ''puff'' behind the car like I use to see last year.


Do you have any idea what could it be ?


P.S. Sorry for my english, not my first language.


Thanks in advance.

Phil

Phil964T

No one ? It's scare the **** out of me

Metal Guru

Kind of sounds like a boost leak.

gr1275

Could it be fouled plugs from too much city driving and short shifting instead of running the engine up to 5 or 6 grand?

Just a thought...
Gary

fritz k.

sounds to me that you´ve seen fuel cuts.

if the boost pressure exceeds 1.2 to 1.4 bar the fuel pumps didnt get no further ground signal. you feel it like a sudden and hard engine interruption.

boost pressure is maybe actually high, e.g. due to wastegate failure, or you face a malfunction of the pressure sensor.

another possibility is the speed sensor, malfunction affects the ignition.

i would go for fuel cuts.

fritz

Phil964T

Alright Thanks guys for the fast replies !

@Metal Guru : Actually, it didn't happens since yesterday. So I assume if it was a leak, it will always happen, no ?

@gr1275 : It's true that I do much more city driving. Actually, the car haven't been much used this summer (maybe 1000miles since May) and I use to drive it much more since 3 weeks. But I always try to let the engine rev to 4000rpm before shifting of I drive it in 2 or 3rd gear in city, depending the speed.

@fritz k. : Thanks, I'll take a look at those possibilties with my Tech. My boost seems normal, it will peak at 0.7BAR. Wastegate has been changed last year.

My car do the ''I don't wanna start when I'm hot'' issue. When the temperature is low outside (between 65-70degres) and I haven't let the engine warm too much (i.e. High revs, high speed, fast acceleration), the car will always start fine.

But if the temperature is somewhere around 86-90F and/or the humidity is high, the car will have difficulties to start or will not start at all after 30-45min of rest. I got to turn the key, wait for the fuel pump to stop maiking noise, then I start the car.....and it won't start. So I hold the key for 10-15sec (i know it's not good but it's better than looking like a complete douche in front of everybody... ) and it will MAYBE start but with pretty much difficulty...the car will idle pretty badly around 400rpm and will *BUMP* *BUMP* *BUMP* *BUMP* *BUMP* *BUMP* *BUMP* THAN normal idling....

Kevin

Phil do you realize that the boost gauge stops at .7bars?

As mentioned you could be overboosting.

However, your warm up regulator could be on the way out.

I would also check your fuel pumps.

Have you replaced your fuel filter?

Phil964T

Hi Kev,
What should be the normal boost for a 3.3 turbo ? I'll take a look at the regulator. Also, the 2 fuel pumps have been changed last year. I tough fuel filter could be the problem too. Will check that as soon as I'll put the car in storage for winter.

Thanks buddy

fritz k.

0.75 to 0.81 excess. as kevin wrote, OEM gauge shows max 0.7 bar.


this means measuring control pressure warm and cold. ask your tec wether he´s able to do that.

i think that the warm start problems are another issue.

fritz

Phil964T

So how do I make sure it's really 0.7 BAR ?



Yeah that's what I meant. He'll be able to do that.

fritz k.

the question is, how do you make sustainable sure, that pressure is not much more than 0.7 bar.

by measuring (with an after market boost gauge) and controling (with a proper working wastegate and perhaps a boost controller, manuel or electronic).

fritz

Phil964T

Alright I take plenty of notes and gonna forward that to my tech.

Thanks guys you've been helpfull.

Should have stick to my first idea, 993C2

Bernard

You wont think that once its running right

Phil964T

Yeah was just kiding. I do prefer 930/964T... They are just the best sport cars ever. Pure Raw.