924Board.org

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

Hello guys,

I am trying to bring a 924 NA from 1981 back to life. The previous owner didn't drive it for almost 15y. Before he stored it, it was running smootly (according to him.)

Now I replaced all the fluids & filters, overhauled the starter, renewed the spark plugs, repaired the fuel pump and the fuel pump relay. When I try to start i, it is not going around smoothly. With the spark plugs removed (no compression), it is going well.

When we tried pulling it to life, it was no succes.

It passed the injector test from the haynes manual and it is giving sparks, but it still won't start.

So my question is, where to go from here because i'm running out of idea's...
My feeling is telling me that it's the CIS system but how to check without the engine running?

Steven

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

How do the spark plugs look? Are they fouled?

Does the air meter flap move smoothly?

How about vacuum leaks? Verified via smoke machine?

Have you tried spraying some starting fluid in the intake and seeing if that helps?

BTW, here's some links to building your own smoke machine for testing for intake leaks:

forum.e46fanatics.com/showthread.php?t=445181

You can also use a cheap Halloween or Party smoke machine:

http://www.garagejournal.com/forum/showthread.php?t=31963

Good luck!
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

Thanks for the reply

Spark plugs are new.
Air flap is moving freely.
Starter pilot is also not doing much

I willl try to do the vacuum test this week

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Yes, but after trying to start, how do they look?

They can foul really quite quickly.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

Ow sorry, they foul quickly indeed...

Ozzie · Posted: Tue Oct 13, 2015 7:13 am Post subject:

too rich when starting will foul the plugs very quickly
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

Yeah so what you are saying is that the CIS is faulty?

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Jump your fuel pump so it's running with your engine off..

With the air metering plate at rest turn your air screw on the distributor clockwise until the injectors start to spray a little then back counterclockwise just untill they stop.. That should be a good base setting to get you started..

When trying to start it you can also go under the hood and move the airplate a touch before cranking, spraying your injectors a bit, to prime your cylinders with a bit of fuel to start it.. Just a little though you don't want to flood it..

"" When I try to start i, it is not going around smoothly. With the spark plugs removed (no compression), it is going well. ""

Is it acting like your ignition may be too far advanced and its firing too soon making it crank not so smooth possibly?

When you remove the plugs and crank it the cylinders don't spray out gas or water from the plug holes do they? As in hydro-locking, make sure your injectors aren't spraying with the fuel pump on and the metering plate at rest..

Check and make sure your cam timing is correct also with the dot on the cam pulley and the notch in the crank pulley..
_________________
80 Turbo - Slightly Modified

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Also here is a good procedure to test, play with, clean out, and understand your CIS system..

Paul · Posted: Thu Oct 15, 2015 10:00 am Post subject:

Check valve and static ignition timing (once valve timing is set, make sure the rotor is pointing to #1)

Check firing order.

Do a compression check.
_________________
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.

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

Thanks for the advice!

The air mixture screw on top of the distributor is not doing much, i will investigate tomorrow.

The results of the compression test are good.

Engine is going around smoothly now with the starter, it was a problem with the cable. But engine still not starting.

Wareagle32789 · Joined: 23 Sep 2015 Posts: 39 Location: Winter Park, FL

I have seen a lot of references to Techron in these replies.

Which product are you referencing: The gas additive or the one marked fuel injector cleaner?

Thanks!

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

the injector cleaner.
_________________
erstwhile owner of just about every 924 variant ever made

sermeussteven · Joined: 07 Oct 2015 Posts: 18 Location: Belgium

It finally fired up today! Oh boy, that was a good feeling!!
The crankshaft was 20 degrees misaligned with the camshaft. So that story of 'working untill the end' was a load of sh*t!

How it gave good result on the compression test I don't know.

Thank you guys for all your advice!!

Ozzie · Posted: Wed Oct 21, 2015 9:21 am Post subject:

now give it a good tune,
AF ratio
ign timing
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance