Motor loop niet lekker bij lage toeren (1,2,3,4 of 5 vers.)

[PK]

Hallo,

Sorry for the English, my written Dutch is very limited.

I just purchased a 1983 GL5 with 126,000 km. It was not running well when I purchased it so I replaced the spark plugs, wires, distributor cap, rotor and air filter. I have also filled the carburettor damper with Automatic Transmission Fluid (ATF). This has solved all the running problems except one.

If the throttle is open a small amount in any gear, for example, ~1200 RPM in 1st gear, the engine surges and hesitates, almost like a slight misfire.

I have some theories. (1) the vacuum delay valve to the distributor is missing, (2) the new spark plug wires are 'leaking' to ground causing the plugs to not fire properly, (3) the timing chain is stretched (it is the original), or (4) the carburettor (Solex 175CD), needs a rebuild.

Any suggestions?

Thanks and take care,

[PK]

Thanks for the quick reply. I haven't played with the mixture yet, could be that it is too lean due to a (?) vacuum leak. I will check this tomorrow with my vacuum gauge. The engine does not idle as smooth as I think it should so mixture could be a factor.

Yes, the car is the brown one that was for sale on MP. It is an original car from Emmeloord (where I bought it). It appears to have only had three owners and includes some service history. It is in quite good condition as it was always kept in a garage and was undercoated in 1987. This car is only a temporary solution for me - I need a vehicle with lots of trunk space to help with my 2CV restoration. When the 2CV is finished (summer 2007), I will sell the SAAB. As much as I would like to keep it (great cars - I had a 1978 99 GLE Combi in Canada), I won't really need it when the 2CV is finished.

Thanks and take care,

[PK]

Hallo Josephine,

Your comments add some weight to my concerns about the set up of the carburettor. Time permitting, I will spend a few moments adjusting it this weekend. I don't have any tools specific to this carb but I'm sure I have something in my garage that fits. Failing that I'll order one (18.75 Euro), from;

http://www.bccp.nl/shop2/enter.html

Regarding the 2CV as a daily driver - it won't be. My better half (aka wife), and I choose to live in NL (I'm originally from Canada), to change our lifestyle and not have to use a car for transportation (that's why we have 9 bicycles . So the 2CV is a 'hobby' car only - to have fun in when we do want to drive somewhere.

Thanks and take care,

[marq101]

Perhaps the air/fuel mixture is too lean? With the correct tools you can easily adjust the carburettor.

Is this the brown 2 door 99 offered for sale on Marktplaats a few weeks ago?

I agree with Josephine. If a car surges on part and steady throttle often the mixture is too lean (for whatever reason)

If all pheriphiral things are ok and you turn to the carburator, cleaning is always a good basis to start. Don't touch the main jet because it has got zilch to do with part throttle fuelling. It's the idle jet or pilotjet (if this carburateur has them) you need to look at. These jets control 100% of the engine idle and 25% of the transition onto the needle. Maybe raising the needle a notch might also do the trick

Good luck
Marc

[Paul99]

I think you should also (or maybe first) check the breaker points on the ignition. They caused me a lot of trouble on my '83 99. My find guess was also the mixture but even after I rebuilt the carburettor, the engine wouldn't run properly. Adjusting the points did. 5 minute job...... While you're at it: also change the capacitor. Points + capacitor are aprox 10 euro together.

@marq: the Stromberg carburettor has only one needle, operated by a membraan (don't know the proper english word at the moment). The only (possible) adjustments to the mixture are done by raising or lowering the neelde (with a special tool).

[Alex B]

Hey PK,

I have the adjusment tool and if you want you can borrow it. Wormer is a 20 minute drive from Purmerend.

Alex

[PK]

Hello Marc, Paul, Alex,

Your English is excellent - much better than my Dutch

Marc - I'm focusing my attention on the carburettor. Today I played around with the carb and noticed that the stumble is noticed at idle speed and also at higher RPM in neutral. I've rulled out an ignition problem since a misfire would also be present under load. Although I may change out the new NGK resistor spark plugs for non resistor as a test.

Paul - your theory on the points/capacitor (sometimes called condensor), is a good one. My car has electronic ignition (original), so this can be taken off the list.

I checked the carb diaphram today and it is in good condition. The needle 'appeared' to be in the correct position although it is difficult to determine if the 'shoulder' is flush with the bottom of the piston. I'll know more when I have a chance to adjust the carb with Alex's tool.

By the way, your choice of membrane is very close. Membrane is typically used in the medecine. Definition - a very thin layer of tissue that covers a surface (like a cell).

Alex - much appreciated gesture. I've sent you an e-mail with my contact details so we can set up a date/time that works for you.

I will update this e-mail thread once I have the problem sorted. Thanks again and take care,

[PK]

Hello Marc, Paul, Alex et al,

SORTED!!!

Marc's reply confirmed my suspicions about the carburettor being the cause of the problem. With the help of Alex's tool (and his explanation on how to use it), I adjusted the needle height with the engine idling. I was in shock as to how lean the mixture had been set - it took almost 5 turns of the screw (clockwise), to smooth out the idle speed. A 20 km drive confirmed that all the 'stumbling' problems had been resolved.

This situation is a classic example of the value of a forum. Gentlemen, thanks again. (Alex, as promised, I'll give you a call and return the tool this weekend).

[Paul99]

5 turns . I can notice a 1/4 turn...... I think you might want to hold on to the tool until you filled het petrol tank again. 5 turns is really a lot and I think you might want to check the fuel consumption.

Happy

[marq101]

Tadaaaaa.

[Alexander]

Paul,

My carb also needed almost 5 turns to get the CO right and to smooth out the idle speed.

In my case it was caused in the past by the former owner trying to get the Saab a new APK after failling on the CO. After installing the KN-filter and making the holes in the filterhousing (?) the engine got to much air with less power as a result. Especially on cold days when the air is more compact the Saab suffered this problem.

At the last two APK's the CO was not a problem and the fuel consumption is still at 1/11 or 1/12.

Alexander