Author Topic: Cold start lever (Read 4855 times)

mbr · « **on:** September 05, 2006, 08:21:20 pm »

While adjusting my timing ('82 1.6na, Bosch pump), I noticed something odd about the cold start lever. The dial indicator was in the pump and set to 0, ready to be timed. I remembered to make sure the cs lever was all the way in. As I pushed it foward, toward the belts, with my finger, the dial indicator advanced a little.
Isn't the lever supposed to retard the timing as it's pushed in and advance as it's pulled out? Why would the dial indicator show the reverse???

QuickTD · « **Reply #1 on:** September 05, 2006, 09:18:15 pm »

If the cold start lever was incorrectly installed, or the stop was bent, the cold start cam could go over center and apply a bit of advance when pushed backwards. I suspect lots of injection pumps behave in the same manner as yours. I wouldn't sweat it too much, the cold advance cam likely "finds" the point of least advance during operation due to engine vibration and spring pressure from the advance mechanism. You probably should have left it there while timing it, instead of pushing it all the way back.

mbr · « **Reply #2 on:** September 06, 2006, 08:39:19 am »

Quote from: QuickTD

If the cold start lever was incorrectly installed, or the stop was bent, the cold start cam could go over center and apply a bit of advance when pushed backwards. I suspect lots of injection pumps behave in the same manner as yours. I wouldn't sweat it too much, the cold advance cam likely "finds" the point of least advance during operation due to engine vibration and spring pressure from the advance mechanism. You probably should have left it there while timing it, instead of pushing it all the way back.

So perhaps I should work the lever and find the point af least advance, then time it?

QuickTD · « **Reply #3 on:** September 06, 2006, 07:27:20 pm »

Thats probably the best approach for the time being. Of course the "proper" thing to do would be to pull the pump off the engine, lock the pump pulley somewhere on the rising edge of an injection stroke, install the timing guage and set the adjustable stop on the cold start advance so that it stops the lever at the point of least advance. Not fun...

mbr · « **Reply #4 on:** September 06, 2006, 08:04:11 pm »

Quote from: QuickTD

Thats probably the best approach for the time being. Of course the "proper" thing to do would be to pull the pump off the engine, lock the pump pulley somewhere on the rising edge of an injection stroke, install the timing guage and set the adjustable stop on the cold start advance so that it stops the lever at the point of least advance. Not fun...

I got it adjusted as best it can be. What a moronic design. The angle of the cable in the bracket and the angle of the lever doesn't allow the lever to be fully pulled in the advanced position. Putting the mechanism on the side between the pump and the block was also a lapse in intelligence. Yechh.

QuickTD · « **Reply #5 on:** September 06, 2006, 08:34:13 pm »

The mechanism needs to be on the back of the pump, due to the direction of rotation of the engine/pump it must push the timing piston towards the front to advance the timing. The VE pump isn't a VW product nor is it specific to the VW. Some applications have the manual cold advance cam on the opposite side of the pump, but they reverse rotation. A poor adaptation maybe, but I guess thats what they had to work with...

For real all out nastiness you should see where they put the pump on a eurovan...