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9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

Hello. I just started my 931 for the first time since November. Back then there was nothing wrong with it. Now there is.

I preheated the engine with a block heater (it's still pretty cold here) and then started it. It started right away and ran very smoothly. Nice.

But after I had driven it for only 2 kilometres there was a sudden loss of power and lots of popping from the exhaust. I just barely got it back home.

I looked under the hood and the exhaust manifold was glowing red! It has never done this trick before. Apart from that everything was looking ok.

Any ideas what the heck is going on?

PS. I noticed that the boost gauge was showing boost but it still felt like there was none. Strange.

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Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

924guy · Posted: Sat Mar 22, 2008 10:46 pm Post subject:

my first thought is an exhaust system restriction, rodent nest, collapsed cat material , stuck waste gate, or something like that...
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Eric
78 924
82 931 SE "smokey"
99' VehiCross
Y2K Honda Insight
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9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

Ok, I will check the exhaust. I have no catalytic converter btw.

I just tried to start it up again and it did. However, idle is very, very low and it is not willing to rev at all.

I'll look for my overalls, tools and refreshments.

Until then any other ideas are welcome!
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

Smoothie · Posted: Sun Mar 23, 2008 1:24 am Post subject:

It might be as simple as a bad connection at the DITC box. An unplug-replug of the rectangular 12-pin connector normally fixes this for a while. -This used to fix it for 6 months to a year for me. Since the time I disassembled the connector and -slightly- closed each female terminal with pliers, it hasn't happened again.
A key symptom of the connector problem is the tachometer needle will flop around, out of time with the engine speed, along with popping, backfiring, no power, etc.. This problem is also moisture-related and is more likely to occur on a rainy/humid day.

Could also be that a vacuum line has developed a leak.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Paul · Posted: Sun Mar 23, 2008 2:33 am Post subject:

Take a peak at your timing belt and camshaft timing.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

I just came back from the garage. Quite a mystery still.

Noticed few things:

-plenty of exhaust pressure, I doubt it has a clogged exhaust

-on startup it is almost acting like a normal car but when engine temperature rises, symptoms appear and it becomes undriveable

-I shook vacuum lines when it was running and there is no response there. I also cleaned some contactors. I can't see any cracks on vacuum lines surfaces

Smoothie: I checked the DITC box. Connecting surfaces were clean and shiny.

Paul:I will check my timing tomorrow.

Earlier today I found this: http://www.924board.org/viewtopic.php?t=17255&highlight=
He had exactly the same symptoms! Unfortunately there is no outcome on that thread.

I'll call it a day and go to sauna now. Maybe my good friend Mr. Beer has some good ideas.
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

Dennis, I'll double check DITC tomorrow.
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

dpw928 · Joined: 02 Nov 2002 Posts: 1860 Location: owasso, ok 74055

Also check the wires going into the connections. One of mine was broken and only connecting with a few strands.

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

sandgroper · Joined: 07 Dec 2002 Posts: 108 Location: in limbo

your turbo is toast,ask me how i know

9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

Cedric · Joined: 27 Aug 2004 Posts: 2809 Location: Sweden

Hm, thats whats happens when ignition timing is set to late. Dont ask me how i know

. Thoug weird that it could happen on a DITC car. Check all ignition parts i my tip. How can you be out so early ? We have snow over here, finland should be worse

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1980 924 Turbo
www.instagram.com/garagecedric/

Smoothie · Posted: Sun Mar 23, 2008 8:50 pm Post subject:

Paul · Posted: Sun Mar 23, 2008 11:16 pm Post subject:

As always check your system and control pressures, maybe your WUR is sick.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

9xx · Joined: 18 Jun 2006 Posts: 627 Location: Jarvenpaa, Finland

I didn't do much today. I started with ignition module. There was some greenish hue over it (on plastic parts) but it wasn't oxidation. I opened it and inside there was some very strange stuff. I guess some PO had sprayed some kind of chemical there. And not just sprayed but maybe poored the whole can inside.

Again, greenish hue on the side and pinkish in the center, where the contactor pins are. I got so upset because of that bizarre gunk that I started to clean both of the sockets and spend maybe 1,5 hour cleaning them.

Well, now the ingition module is very clean, factory clean! A bit of a overkill, I know.

I started the car and it sounded very good. Normal I guess. Then I started it again and it was crappy.

Start 1: fuel pump buzzing a bit.
Start 2: no sound at all

I looked at the fuel pump area quickly before I left. There was some serious oxidation on some connectors...

Maybe tomorrow I have more energy to sort this problem out.

Cedric: There hasn't been much of a winter here. More like eternal autumn. Basicly no snow at all.
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944