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mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

i was driving my 80' 931 to my buddys house for a night of drinking and catcthing stuff on fire. well on the way there his road is like a "roller coaster" and i got a little air very little but still. well right after that coinsidently the power dropped dramaticlly. didnt think to much of it cause i could see his house and it happened a while before i assumed the intercooler hose blew off. wrong. my #1 cylinder either isnt firing or isnt getting fuel or has low compression . well icaught a ride home from another friend and will begin in the morning. my real Q. is i just put in a msd 6A ignition setup in. coil, module, wires the whole thing . i have power to the plug . but thats as far as i could test without tools. it seems to be a fouled plug. which are brand new. could it have fouled because of the msd?? or just coincidense? please help? i need this car going by monday my other car isnt running right now and need it for work . thanks guys and ladies. also the msd is wired properly and worked great for the first 2.5 weeks.
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80 931 intercooled,1 bar, and kinda runs right

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

is there a special plug i should be using ?
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80 931 intercooled,1 bar, and kinda runs right

Joes924Racer · Posted: Sun Sep 26, 2004 1:48 pm Post subject:

your getting fire still to the plugs huh and the pump is runnen

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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

couldnt check if the plug is firing yes on the fuel its flooding the #1 cylinder. i know #1 has spark thru the wire just didnt have any tools to check for plug spark.
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80 931 intercooled,1 bar, and kinda runs right

Smoothie · Posted: Mon Sep 27, 2004 6:24 am Post subject:

Hey you're not the guy whos' spark plugs loosen themselves and fall out are you? I guess not or you'd have thought about it already - then again some people can't remember their name after enough beers.

Anyway, I guess that's a possibility. Can't imagine what would cause #1 alone to get an extra rich mix, so that leaves lack of spark as your best guess.
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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

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

well i was wrong all the way around. lost all but 30 pounds of compression in # 1. guess ill have to figure out how to rebuild an engine, not cool at all.
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80 931 intercooled,1 bar, and kinda runs right

Lizard · Posted: Mon Sep 27, 2004 9:59 am Post subject:

I doubt it was due to the slight amount of air, however when using the MSD setup you should increase your gap alittle bit. you are most likely looking at a broken compression piston ring.
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3 928s,

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

hey lizard, since im tearing it down what do you think of putting a set of je pistons in there also would i be able to use any rings with those or do they need to be matched to the piston?
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80 931 intercooled,1 bar, and kinda runs right

Paul · Posted: Mon Sep 27, 2004 12:10 pm Post subject:

Could also be a bad headgasket (1 bar boost + detonation?) or a burnt valve (running lean at 1 bar boost?).

I would do a blow down test.

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

well i was just reading another post on that can i still do one now though? ive taking everything of the engine the block ,head and ex. manifold is still in the car and attached.just had the head completeley rebuilt last year everything in it is new but the cam.guess i could try it before going any further.
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80 931 intercooled,1 bar, and kinda runs right

Paul · Posted: Mon Sep 27, 2004 12:23 pm Post subject:

You have to take it apart anyhow, but I'm one of those guys that like to predict what I'm going to find (years of writing estimates).

So I would bring the low cylinder up to TDC and pump in some air to see where it goes.

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

in the other post i was reading that he had put 60 psi in the cylinder should there be no bleed down at all, and is 60 right?if it does bleed what is that telling me if it goes out the ex manifold its the ex. valve , and if it leaks out the intake it the intake valve? is that right?
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80 931 intercooled,1 bar, and kinda runs right

mick · Joined: 13 Jun 2003 Posts: 183 Location: ohio

guys im out for the night any info or help you give tonight is appreciated. ill reply in the morning. thanks
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80 931 intercooled,1 bar, and kinda runs right

Paul · Posted: Mon Sep 27, 2004 12:47 pm Post subject:

For this test, the PSI doesn't matter much, just put the low cylinder to TDC and pump in some air (make sure the car is out of gear).

If it leaks at the:

Intake manifold: bad intake valve
Exhaust manifold: bad exhaust valve
Oil filler: hole in piston or broken rings
Radiator coolant tank: Bad head gasket or cracked head or block.
Another spark plug hole: Bad head gasket

As Lizard said, it's probably broken rings.