924Board.org

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

seeing a photo of k jetronic I noticed this particular on the right.
In point I have only a opened hole, it is normal or there must be something?

Harm · Joined: 02 Apr 2009 Posts: 1378 Location: Holland

The one on the left:
Yes, when you are done correctly setting the airflap, you take out the Alan Key you used and cap it off with a rubber plug so it won't draw false air.

The one on the right:
That it is not a Porsche 924 part. I guess this pictured CIS meteringhead is of a Volkswagen Golf GTI.

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

But I have a hole in this position, it's normal ?

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

My 931 has a port there for fuel vapor recovery.
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Harm · Joined: 02 Apr 2009 Posts: 1378 Location: Holland

@ chris79
What type of 924, and year of build are we talking about?
Put this information in your signature.

On the 924 there is a hole/tube but it should be closed/capped by a rubber cap.
Since ~1980 the engine's vapor return to the inlet by the connecting tube between metering-plate and throttlebody… so your air filter doesn't fill up with oil

See PET for construction details.
_________________
Porsche 924 NA 1982 LY7A/A3A3 _ Greater driving pleasure never harmed anyone.

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

I have european 924 1979 no turbo.
But the hole whitout cap can create some problems ?

ThomasJoseph315 · Guest

It's the crankcase ventilation tube intake port. There should be a hose from your block to that to suck in the oil fumes. Is important for releaving crank case pressure at high rpms. Also is an emissions hose if your in such a state.

Only other thing I could think of is if the part was off a 931 and had a bypass system for the wastegate some year and they routed that to that port. I had a 94 Eagle Talon TSi that had that.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

LOLx2
_________________
Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

leadfoot · Posted: Sun Dec 21, 2014 1:36 pm Post subject:

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

Another question, 924 aspirated of 1979 have 'fuel pump check valve' ?

My problem is alwais that control pressure don't increase when warm and the engine has no power!

I temporally replaced wur with external pressure regulator weber 3 bar and I did these tests:

- engine off - fuel pump relè bypassed:
control pressure increase when I change pressure whit allen on pressure regulator from 3.5 bar to 6.5 bar, is correct

-engine on:
control pressure cold 1 bar, but when I change pressure on regulator whit allen the control pressure does not change, It's possible ???

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

Someone have ideas?

leadfoot · Posted: Fri Dec 26, 2014 11:41 am Post subject:

test WUR electrical connection is getting 12V,
test fuel pressures at WUR with CIS test kit,

failing those two tests, replace WUR
Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

miraculously the engine now runs well.
I have not replaced anything, I opened the distributor and reassembled as before, clean the spark, before the pressure control was only 1 bar, now is almost 4 bar, great.
I just changed the piston of the distributor with the original one, which is slightly different, and I noticed that the fuel pump is less noisy.

chris79 · Joined: 29 Jan 2014 Posts: 551 Location: milan

I compared the plunger of the distributor, the new one (in photo 2.) was larger than a few microns, it is possible that the pressure control was only 1 bar because of this?
Now it is even 4 bar and the engine run well, before the car don't move!

1)

2)