924Board.org

[Octane]

Still working on my winter project that's taken far too long, getting frustrated as hell and just want to drive this thing in the nice weather!

1977 Porsche 924 N/A, 56,000 miles. Bought last spring from an enthusiast and drove it all year without incident. Lots of maintenance receipts came with it, seemed like a well maintained and cared for car.

Pulled the engine out in the fall to clean it up, paint the block, do some maintenance stuff (timing and v-belt, spark plugs and wires, cap and rotor, new gaskets etc.) I had planned to install the euro pistons I bought and upgrade the cam but when I pulled the valve cover and oil pan everything was immaculate and showing very little wear, so I decided not to touch it.

However I did convert it to carburetors. I got a pair of Solex C-40 2-barrels and manifold from somebody on eBay, went to pick them up and talk to him for a bit. They were off an Alfa Romeo but he had run them on two of his 924's and said they worked great. They were in excellent condition and only $120 so I bought and installed them. We had lots of emails back and fourth about setting them up and etc. As far as I know everything is kosher, correct fuel pump and return installed, injector holes plugged, etc. The only thing is the vacuum advance isn't hooked up, but I believe it should still start and run without it for now.

So I just finally got everything re-installed, trunk mounted battery wired up. It's turning over great, I'm getting spark and it's getting fuel. It sounds like it's trying to fire and a couple times has kind of ran rough for 3-5 seconds then stalled. However occasionally it will backfire through the carb and smoke will actually come out. To me this would indicate a timing issue, however the t-belt is timed correctly and the distributor seems to be aligned properly.

What am I missing here? Is there anyone in the southern Ontario area who could come help me out in exchange for beer and gas money? I have put a lot of time and money into this and it's frustrating to have it sitting in the garage while I'm driving an F-350 dually around instead.

Thanks...
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- Brendan
1977 Porsche 924

[Rich H]

Not wishing to insult your intellignece but are you sure the timing is OK? Leads in the right order and that sort of thing?

Sounds daft but check with Haynes manual and go through everything. It's easy to overlook something, BTDT.

Remember:

The cam timing marks are on the back of the cam pulley (The words on the pulley face the back of the car!) and on the edge of the front pulley.

The flywheel timing marks can be any multiple of 60 degrees out.

Standard timing is the +10 degree mark for 10 BTDC (Not the -10 which would make more sense)

And more besides.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[DOCO]

+1/\ but could also be flooding.where abouts you in hammer town?
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Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
_______
/______\
[+]___[+]
\0 924 0/
[__]..[__]
"WEBB STR"

[DOCO]

oh and did you say...BEER!!
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Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
_______
/______\
[+]___[+]
\0 924 0/
[__]..[__]
"WEBB STR"

[924-76]

[Octane]

No I have not put a timing light on it as I do not have one. However I was extremely careful to reinstall everything exactly as it was removed and lining up dots etc. as per Haynes manual. However it's possible, I'm just a dumbass eighteen year old kid who wants to go fast. I'm in Rockton about 20 minutes west of Hamilton.
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- Brendan
1977 Porsche 924

[reilly525i]

im afraid id have to agree with the boys here. . sounds like plug leads or timing. . thats how mine behaved until I got it right.
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"There are no kings inside the gates of Eden"

80 n/a 924.
76 alfa romeo spider
e34 525i.
xj6 vanden plas
vintage Sunbeam 6 speed bicycle

[Rich H]

Easy check then if you are confident that it's all correctly assembled: get someone to crank the engine while you twiddle* the distributer.

If it's just the tignition timing then it'll start on a wide range of timings, just get it runing and twiddle it until it'll idle reasonably. You'll hear it pick up as the timing comes in.

If it's something more fundemental then it'll do no harm to try the above.

Oh and as you are dealign with carbs make sure you have a fire extinguisher. I am not joking. only takes a backfire to throw fuel everywhere.

During the fitting of EFI to my old N/A an injector blew out and I was extrememly lucky it didn't ignite.

I also set fire to the back of the old car a bit when the alt battery cable dropped onto the block (I'd reconnected the battery to check somethign and forgot to disconnect it again) and a braided brake line was the only pathe to earth which promptly melted and set fire to the brake fluid.

*Technical term: back off the clamp bolt and rotate the dizzy
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[dpw928]

Backfiring through the intake indicates too advanced timing or an intake valve staying open. Did you reset the valve clearance when you put it back together? If those are OK try slowly retarding the ignition timing (turn clockwise).

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

[DOCO]

wow your in the middle of no where!!between the hammer and cambridge.well do you work days or nights?im off on thursday and could make a detour to help you out.i have all the nessary tools.plus id like to see your carb convertion.as i am doing one as well.dave call me at work 1-800-454-0797
_________________
Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
_______
/______\
[+]___[+]
\0 924 0/
[__]..[__]
"WEBB STR"

[ideola]

Double check the leads order: should be 1-3-4-2 CLOCKWISE around the distributor. If you have it oriented counter-clockwise, you'll only be running on two cylinders and flooding out the other two. Make sure you know which connection on the ign dist is #1, and go from there.
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erstwhile owner of just about every 924 variant ever made

[JMALONE26]

I agree with everyone, Check ignition timing. I did my Corvette over last year and my distributer was off a little, it looked right but it wouldn't start or if it did, it ran rough, stalled out and smoke came out of the throttle. Odd enough, since it was a chevy I swear I could have driven it like that!
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93 Mustang
87 Fiero
88,89,89 Daytona Shelby
80 924 N/A
84,89 LeBaron
89 Pulsar
87 Merkur XR4Ti
86 Corvette
72, 74 MGB GT
86 Audi Coupe GT
82 Porsche 931

[Slam]

As above re: 1-3-4-2 firing order, and have an assistant crank the engine while you slowly twist the distributor to advance or retard the timing. That's all it should take to fire the engine if your timing is close. One thing - pop the cap off and check where the rotor points when you've got the cam at TDC, although you've probably done that already.
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'84 944 - kid blew motor
'83 944 - resting comfortably. For 12 years
'87 944 - sideswiped by trucker
'80 924 - gone
'78 924 - gone
'77 924 - rusting comfortably

[joejax]

Just curious, but why would we abandon the CIS on a car with only 56K miles on it?

Seems like it should have been OK for a little longer, mines got maybe 80K on it and it's been PO'ed to near death.

I've been tweaking and cleaning stuff forever, and it does get aggravating but seems to be operating OK.

Here I go again with an attempted thread hi-jack, but I'm only wondering...
Is it better to keep the CIS or open up another can of worms with a carb conversion?

I guess I would need to weigh all of the options, price, difficulty, reliability, etc. or maybe just a matter of preference.
And I'm sure this has been discussed at length before, but at 56K?

Hey Octane, I'm not trying to be an ass or anything, sounds like you have a great car there, I wish mine had been taken better care of
before I got it, I guess I'm just wondering when should I just give up on the 'ol CIS.
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I got nothin'
Uhhh...you got any pics?

[Octane]