ignition timing, how to adjust? idle L Jetronic

[Pepite73]

[Wildthings]

[SGKent]

[Pepite73]

Thanks SgKent and wildthings. That's a good idea. Do you have a picture of what I need to remove (the electronic ignition) to lubricate properly and know where to put the oil drops?

[Wildthings]

[SGKent]

did you put four or five drops of oil on the wick under the rotor to be sure the mechanical advance has adequate lubrication? It needs a couple drops of oil once in awhile when servicing it.

[Pepite73]

I have no leaks on the smoke tester. When I drive at 100 km/h the engine does not go down, it remains at 1650 rpm and -15 degrees btdc at idle while I had set it to -7.5 at 1080 rpm. Even after a few minutes it does not return to 1000 rpm. So I wonder if it is not the vacuum igniter? To test the brake lever I do not know what the procedure is.

[Wildthings]

[mikewire]

Is that your throttle body in the picture? It doesn't look quite the same as mine, and I have a similar setup to what you have.

Also, Robbie's advice was solid...turning the idle screw clockwise (to the right) will decrease idle. If it doesn't then you have a leak in the S-boot somewhere.

S-boots crack in the peaks and valleys of the molding and leak, and the other two connections can also leak. Did you do the smoke test, and what did you find?

If you can post a few more pictures of what you have setup, that may be helpful.
_________________
-Mike

@countdowngarage
@bigskyeuro

1972 VW Kombi 9 Passenger Deluxe w/ 2.0L F.I. VWAC swap
1965 VW Beetle Deluxe Bahama Blue

[Pepite73]

I plugged the hole in the large hose that attaches to the intake pipe with a cap.
I started it and revved to 3000 rpm.
When I suddenly closed the throttle body, I felt a suction with my finger,
but it seemed weak...

So I'm wondering if that's the problem.

I don't know where to find a deceleration valve?
I saw two for sale on the samba.

You're talking about testing the deceleration valve, right?

[Wildthings]

With the engine idling remove one hose at a time from the intake air plenum and plug its nipple with your finger. If one makes a noticeable difference in your idle speed you may have found your culpret. The engine may stall when you remove some of the large hoses so have a stopper or other way to block those nipples off if you don't have a helper to start the engine while you plug the nipple with your finger.

How well do your power brake work?

[Pepite73]

I still don't understand why my engine speed is 1200 rpm at idle.
However, I checked the following:
- Compression is at 90 psi on all 4 cylinders.
- I adjusted the rocker arms and everything is fine.
- Cylinder head temperature sensor I is new and ok.
- Sensor II on the air flow meter is measured at 2230 ohms (normal between 2.3 and 2.7 kOhms) if I test between 6 and 27.
- I have no air leaks in the air circuit (I performed a smoke tester and found no leaks).
- My additional air valve is checked OK: it closes when the engine is warm (and 30 ohms are OK on the tester).
- My fuel pressure regulator is checked OK: 2 bars if I reconnect the air distributor hose to the pressure regulator.
-My ignition system is good, the plate inside the distributor moves well.

When I set my advance to 7.5 BTDC, I'm at 1200 rpm.
If I set it to 5 ATDC, I'm at 900 rpm.

My engine has the number: GD 021625 (September 1976). It's a 2-liter L Jetronic injection engine.

The vacuum distributor is 022 905 205 S / 0231170093.

When I refuel, I smell gasoline when I go around roundabouts. Maybe the vent hoses are porous, but no leaks were detected by the smoke tester.

I have a fuel consumption of 9.6 liters per 100 km.
I have an ultra-long gearbox with a differential.

I don't understand why I'm always idling too high. Do you have any ideas?

(I'm going to check my cold start valve tomorrow to make sure it's not leaking...) and i must check the decel valve.

[Pepite73]

you mean when i rode? because it usually comes back to 7.5 btdc. when do you want me to take the measurement? the timing goes up then sometimes stays at 10 btdc i'm getting my new timing light this week because it died on me yesterday

[airschooled]

What is the timing at idle when warmed up?
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[Pepite73]

Yes, I clamped it and it doesn't lower the rpm. I had already changed it to new and checked.

[Wildthings]

Have you checked into whether your AAR (auxiliary air regulator) is closing fully once the engine warms?

Your throttle plate clearances look good to my eyes.

[Pepite73]

I noticed that this winter when it was cold my idle speed was good at 900 rpm and since it has been warmer it has gone completely haywire about 1300 t/m

[Pepite73]

I didn't understand why you said it was worn out if it didn't have the hole?
Why?
I'll put a picture of the inside of the throttle body and the number. Thanks a lot for your help Robbie

[img]https://www.thesamba.com/vw/gallery/pix/2283009.jpg[/img

]

[airschooled]

If you’re bottomed out and have zero vacuum leaks, it’s time to remove the s-boot and look at your throttle body. If it has the hole in the center like this one, it is for a DVDA distributor.

If the hole is absent, your throttle body is probably worn out.

If you do have the hole, you can solder it shut to return functionality to the file speed screw. Or, if you have two vacuum nipples on the throttle body, use a DVDA.

Robbie
_________________
One-on-one tech help for your vintage Volkswagen:

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[Pepite73]

Thank you Robbie,
I tightened the idle screw fully as you indicated. I loosened the screw on top, i.e., on the air flow meter, but that doesn't lower the idle speed.

Thanks for your reply, Robbie.

Pépito (Xavier)