924Board.org

[Johann]

Couldn't agree more Dan. My Turbo ran quite rough when I just finished restoring it, Everything was within spec but after 3000km it runs perfectly smooth (well, as smooth as a toofah can be). I truly think things need to settle and go through a couple of heat cycles to find their sweet spot again.

Why drive it hard? because you need to get parts of your system very hot again and that only happens when you drive it hard. Hit the red line often, don't shift up for a while etc. You will see that valves, hinges, pumps, bearings, etc start working better. You will burn carbon deposits and by increasing the amount of fuel flowing through the system your injectors will clean themselves.

Just one more tip use contact spray or WD40 on all electrical connectors...it does wonders for conductivity.

[Rasta Monsta]

Suggested the same back on P9. He ain't buying it.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[morghen]

I remember back when carbs were the thing and cars were moody, somehow human. Then fuel injection changed them closer to machines and then electronic fuel injection further stripped them of any seemingly human characteristic. Maybe that's why we don't love new cars...they are sterile and don't resemble humans at all.

Anyway, the CIS is a good system, reliable and performant even compared to much newer generations of systems might I add. However it still has that human feel in my opinion. Its strong and can perform great, but its delicate and influenceable, its a little bit imprecise and even to a small degree moody.

My S1 931 had a similar condition when cold, it would shutter and it even seem to misfire. I looked a bit for a fault, replaced some sparkplugs and the rotor and while it was considerably better it still behaved like that.
I then proceeded in driving the car almost on a daily basis and then taking it for a 3000mile trip.
The rough throat was gone after the first week of daily use and sporty driving if I remember correctly.

Who knows, maybe a valve is binding a tiny bit and that's upsetting the combustion cycle until it warms up.
When the weather allows you take it for some drives, enjoy the car...it might be that whatever is causing the issue you're having will go away by itself by just stretching the legs of the car a bit.
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Supercharger and EFI kits
https://www.the924.com

[Last Triumph]

[Last Triumph]

Not much in the way of an update, but an interesting exercise nonetheless.

I was keen to see just how much additional dirt could be removed using an ultrasonic cleaner using panel wipe spirit as the agent.

My starting point were components that I'd scrubbed with a stiff toothbrush using brake cleaner and then blown out with an air line, then scrubbed again, anywhere I could get a brush or pipe cleaner.

Had I not had access to an ultrasonic cleaner, I'd have reassemble d as is, secure in the knowledge that I had them pretty darn clean.

The results were quite astonishing.

Keeping in mind that the bowl the components were sitting in was stainless steel, and the panel wipe spirit crystal clear when I first switched it on.

This was after 8 minutes...



And the other half of the body on the same cycle...



Just goes to show the difference between clean, and clean.

Everything is now sealed in freezer bags awaiting a rebuild kit, as sadly the donated diaphragm is not up to scratch having been installed previously and suffering a little damage round one of the holes.

[Last Triumph]

I'e rebuilt the metering head and come across what may or may not be a problem...

The shuttle valve glides effortlessly into the valve body but tightens up that last quarter inch of travel - the part it would normally move through in operation.

I've cleaned, double cleaned, ultrasonically cleaned, lubed, double lubed, cleaned again etc, etc and it's the same every time, the last quarter inch of travel get tight where gravity won't allow it to fall back out again and I have to physically pull it out again.

I was mega careful putting everything back together and made sure everything was aligned perfectly etc so can;t think where I;ve gone wrong.

Have I gone wrong?

Should I expect it to fall freely right to the end of it's travel and clunk against the end of the valve body?

If I assemble it on the air metering unit and raise the air plate to the limit of its travel - wide open throttle position, then remove the metering head, the shuttle vale is stuck in place and I have to gently pull it out with needle pliers by the tip.

Is this normal and would fuel system and control pressure be enough to keep it moving?

Given that the valve body is rigid, I can;t see how reassembly could cause it to get tight at the end of it's travel.

Any ideas?

[Last Triumph]

Stripped it down and rebuilt it again - it's fine now.

Let's hope it works.

[Fifty50Plus]

Are all the cold start problems gone now???? If so congrats!!!
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1979 924 NA race car H-Prod SCCA
1982 924 NA race car - Sold
1981 924 Turbo sold
1982 924 Turbo sold
1972 911 E race car - traded for Cayenne Diesel
1975 914 1.8 Building for H-Prod SCCA

[Last Triumph]

[Last Triumph]

Just tried a cold start and it's as bad as ever - plenty of coughing, spluttering and backfiring up the intake. No difference.

So we can now eliminate the metering head.

Running out of things to check now.

[Fasteddie313]

I though we eliminated the fuel system a while ago before you started tearing into it and you found problems with that green wire..
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80 Turbo - Slightly Modified

[Last Triumph]

[Cedric]

Are you measuring fuel pressure during start up? I assume you do since this thread is 15 pages long.
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1980 924 Turbo
www.instagram.com/garagecedric/

[Last Triumph]

[brian19600]

I think at this point, I will join the rest and say, drive it for a while. Maybe the problem will worsen or will get better. You've done a lot to it. Get some miles on it. Driving it for a while may give you further perspective.
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78 924