1. 'bant

    'bant Loyal Comrade

    I managed to fix two problems with my Trabant. The first, and most serious was that the car refused to pull in full throttle/full load situations. This made the 250km drive home after buying the car. through hilly and tunneled Norway somewhat more stressful than it should have been. I ended up at 30km/h in second through the longest of the tunnels and on the way up Hemsedalfjellet.

    The problem as I suspected was with the carburettor. My hunch was a sticking needle valve which turned out to be one of a number of problems.
    1) The spring loaded needle valve could be made to stick when facing down
    2) The float level, measured upside down, was set for a needle valve without a spring. Once I replaced the needle valve the float level corrected itself.
    3) There was only one gasket between the carb and the engine block together with some blue gasket sealant. That explained why the front of the engine was covered in a thin layer of oil from the fuel mixture.
    4) The air bypass hose was a bit loose at one end. A jubilee clip fixed that problem.

    The carb looked like a reconditioned unit, all the screws and nuts had paint dabbed on them so it was a suprise to find that the float level was wrong. Although the carb looked clean inside I took out all the jets I could find and cleaned everything again. I had already checked the petrol tank, the bowl under the fuel tank and the fuel flow at the carb end and all seemed good.

    The result on the first test run was that the car accelerated to 90km/h and was still accelerating when I lifted off. Before I fixed the carb the car it would not go faster than 75km/h on the same stretch of road before the engine started cutting out. So that is that sorted.

    I have to say that getting the carb off is a bit of a s@d of a job reminiscent of changing the engine mountings on an old Mini. In both cases you have very limited access to the nuts and can only get a 6th of a turn each time before you have to removed the spanner.The Trabant tricks you into thinking it will be an easy job as you can see the carb mounting nuts where as you can't see the Mini engine mounting nuts. However, the Trabant heater shroud near the carb seems to be made from old razor blades, with numerous sharp edges to catch your knuckles and hands on. If I ever remove the exhaust manifold I will take a file to that shroud and try and make it more hand friendly.

    The second problem was that the electric windscreen washer did not work. I discovered that the motor was getting 6v when the switch was pressed so it had to be some problem related to the motor. My initial solution was to replaced the IFA unit with a generic washer bottle with 12v motor from Biltema. This worked fine but I then decided that evening that I would take a look at the IFA unit, without much hope of fixing it. I discovered that you can easily dismantle the 6v motor, so I did. I bent the brushes to make sure they were making contact and reassembled the motor. It ran with a little mechanical noise, the bearings were just the plastic ends of the motor. A drop of lock oil on each end solved that. I put the motor back in the pump unit and then discovered that it would not turn the plastic pump. So motor off again and I freed up the plastic pump and all worked.

    So I removed the Biltema 12v unit and put back the original 6v unit. Both seem to give out the same amount of water :) I guess that is progress for you!
    Last edited: Sep 17, 2015
  2. Caleb

    Caleb Loyal Comrade

    Question for you... Before fixing the carb you said that at about 75km/h the engine would start to cut out. Would it completely die to the point you had to pull off? If so once stopped would the car restart after just a minute or 2 sitting? I ask because I have a similar issue right now. It seems like it always happens at the same point on the same road. we get up to speed cruising at about 80km/h and all he sudden she just gives up and stalls. A few times I've been able to pull off and pop the clutch to get the car to refire but it usually still stalls out to dead stop. After waiting a minute or so the car will usually fire right back up with no real trouble and continue on home like nothing every happened. It really seems like a fuel issue as opposed to spark or timing or anything. I am wondering if the needle valve is possible staying closed too long and the carb is emptying before allowing more fuel in or if it is something more like vapor lock.
  3. 'bant

    'bant Loyal Comrade

    The engine would die for a second or two and then burst back into life. Then die again and burst back into life it was a bit like riding a bucking bronco... However, sometimes I had to change down into third gear and bump start the engine whilst moving. Cranking the engine would not start it but dropping the clutch at 60km/h in third did for some reason. I also had the same problem in third gear when running uphill at full throttle/full load so it was clearly a fuel flow issue, either carb or fuel lines.

    The needle valve in my car was sticking slightly but they can stick permanently open or permanently shut. Or stick until something bumps them like pulling off the edge of the road when the engine is stalled. I've had both with my Dyane in the past. In my case the float level was also wrong which would cause the needle valve to shut before the float chamber was full. The carbs are very simple devices, easy to pull apart and the carb refurbishing kits from the usual suppliers are not expensive. So I would be inclined to take a look at your carb. Also worth checking that the inside of the fuel tank is clean, fuel flow at the carb end of the fuel line is good, decant some fuel into a jam jar and check it is clean. Remove the cup under the fuel tank and check that it and the gauze filter are clean.

    I have not had the engine stall when coasting in fourth gear either since fixing problems with the carb and warm starting seems to have improved a bit.
  4. Caleb

    Caleb Loyal Comrade

    Ok thanks for the info! Glad you seem to have gotten yours sorted. I think I will be pulling the carb off as you suggested with the refurb kit and clean it out well. Hopefully that will take care of it. I know the bowl under the tank is clean as I have checked it multiple times and the fuel is very fresh. I haven't been able to see an debris in the tank so I am pretty sure its clean. I'll pull the fuel line like you suggested and see what/how much comes out first just to be sure there is no issue there and then the carb will probably be my winter project this year. Since its already almost October the Trabi wont be on the road much longer this year unless we have a very slow start to the winter.
  5. turbofiat124

    turbofiat124 Loyal Comrade

    I knew that the 12 volt models had electric pumps but I did not know they installed 6 volt washer pump motors on Trabants. Just the hand pump. I sort of modified a 6V pump from a pesticide sprayer. I have not wired it up yet. I took some photos of it, but never uploaded them to my photobucket album.

    I'd like to see what this original 6V washer pump looks like.
  6. 'bant

    'bant Loyal Comrade

  7. turbofiat124

    turbofiat124 Loyal Comrade

    Don't know how I missed that one!

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