ssalsa

Hello, I am a person who has a 964 turbo in Korea. I have a problem with my car and would like to hear your advice.

1. It is in good condition when starting cold.
2. Restarting is difficult
3. I exchanged the 1st and 2nd fuel pumps, fuel filter and fuel pressure regulator, but they are the same.

I've tried it, the symptoms are still there and I'm desperate for help. Sorry for my lack of English.

thank you

997 tt/rs

Hi,
unfortunately I have no idea what is the reason but I want to draw your attention to the pumps. Currently available pumps in Porsche or Bosch have lower efficiency than pumps produced years ago for these cars. After replacing the fuel pumps, it turned out to be lean above 5000 rpm. I replaced the pumps prophylactically, only because they were many years old and it turned out to be a mistake.

Karol

ssalsa

[QUOTE=997 tt/rs;18829669]안녕하세요.
안타깝게도 이유가 무엇인지 모르겠지만 펌프에 대해 알려드리고자 합니다. 현재 Porsche 또는 Bosch에서 사용할 수 있는 펌프는 이러한 자동차용으로 몇 년 전에 생산된 펌프보다 효율이 낮습니다. 연료 펌프를 교체한 후 5000rpm 이상에서 희박한 것으로 판명되었습니다. 나는 예방 차원에서 펌프를 교체했습니다. 펌프가 오래되어 실수로 판명되었기 때문입니다.

캐롤[/QUOTE
]

Thanks for the reply. Is it likely that the ISV is broken? When the power is turned on, it closes completely within 10 minutes, but when the power is turned off, it opens only this much as shown in the picture.

fritz k.

No, the auxiliary air valve is ok. It is not only heated electrically but also by engine heat, it opens a little further when the engine is completely cold. If it would stuck you would have either cold start or high idle rpm issues.

In order to find the failure , two things should be done first: ​​​​the system and the control pressure on the warm-up regulator have to be measured and it must be ruled out that the engine is drawing false air somewhere.

As long as it is not clear whether these things are in order there is really no need to look any further.

Fritz

wicks

Does the accumulator failing sometimes cause hot this restart issue? If it is original, should replace it anyway, along with all you've done to refresh the fuel supply system. Or, maybe it's the opposite, bad cold start with worn out accumulator.

Mdiesel64

I encounter a similar issue, actually.

The car starts perfectly fine cold, however on a hot start, it will start (sometimes harder than others) and then will lower to 2-400rpm and start to die out if i don't hit the gas. and keep it at normal idle.

After a moment or so however, it's fine and will idle normally.

Following.

911 2

I had the same problem, turned out to be the fuel accumulator, sits next to the fuel filter, most of my inlet manifold nuts had also worked loose

Nyx

Good chance your injectors are leaking.
if they are old I would recommend replacing them.

you can easily check your residual system pressure to rule out the accumulator.

if the injectors are old you’ll solve the problem and have more throttle response through better atomization.

Scott Dunavant

After taking my 91 C2 TURBO apart last year, I found everything to be shot.