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General Information => Troubleshooting => Topic started by: zozie on October 16, 2009, 03:59:49 am
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Well my beloved mk1 Jetta N/A is challenging my love once again ;D
I had the IP rebuilt abooot a year ago and everything worked fine until recently. IT feels like there is no resistance on the cold start lever at all. I didn't need it until a few days ago due to the weather. In the cold, I usually start without, then once its coughing I pull it out. It always smooths it out. Well not now ::) It doesn't do anything what so ever and like I said there is no resistance on the cable. I did check the lever on the pump side and it moves there.... Is it common??? I really didn't want to take the pump off :P
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Check that the locking screw which secures the cable to the ferule inside the cold start arm at the pump is present and tightened down against the cable.
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Yes it is :-[
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Anyone has an exploded view picture of the N/A pump? I'm not sure if it's possible or not, it feels like the arm is rotating on the cold start shaft if that's possible ???
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Unscrew the cable and by hand pull up on the lever. You should feel resistance. Or connect a timing guage to the pump and see if it does advance the pump?
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Is there resistance felt when you pull the cable out and the car is not running?
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no resistance what so ever....
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Is the problem you described Libby, fixable with out tearing down the hole pump?
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I've had 2 pumps that sort of acted like that but not with no resistance at all though. You know how much a pain they can be when installing a pump and hooking up the cable and getting it adjusted right to the lever and then after 2 or 3 pushes and pulls the damn cable just bends and wont push the lever because the lever seems a little tight. After I started the car then the cable worked fine because it seems like a little resistance was taken from it somehow and has worked very smoothlly since on both pumps it happened on and it is actualy advancing and retarding the timing around .23 it think it is on this last one What makes it work smoother after it starts and stay that way then, is it something that gets freed up inside somewhere ???
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What makes it work smoother after it starts and stay that way then, is it something that gets freed up inside somewhere ???
It's because once the car is running the pump has pressure. The amount of pressure in the pump directly effects how much advance you have. The advance piston is now being pushed by pump pressure so when you use the cold start you don't have to pull as hard because either the piston has already moved, or the pump pressure is acting like an assist.
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What makes it work smoother after it starts and stay that way then, is it something that gets freed up inside somewhere ???
It's because once the car is running the pump has pressure. The amount of pressure in the pump directly effects how much advance you have. The advance piston is now being pushed by pump pressure so when you use the cold start you don't have to pull as hard because either the piston has already moved, or the pump pressure is acting like an assist.
Very well spoken :)
When I got the pump back and installed it, it was so tight, with the engine off I couldn't even pull on it. Once it was cranking, I was able to pull it.
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can over advanced timing make the cold start not respond?
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can over advanced timing make the cold start not respond?
No. The cold start will just further advance it. If you have too much internal pump pressure (or not enough advance shim springs as per a mod listed in the FAQ section) then the cold start lever may have no effect because the piston will have already advanced past the operating range of the cold start advance at idle.
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So if I understand what you are saying, a modded pump from Giles would not see cold start response then.
Would that be correct?
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I don't know. I don't deal with the testing of pumps at this time so I don't know how they are setup on the bench. I suppose depending on the customers requirements that it may be built that way but I'm not sure.
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even if the cold start is overcome at idle it will still assist in the starting of the vehicle over having it pushed in.
yes, that's correct unless your timing is over-advanced. That can then cause hard starting because the combustion is trying to push the piston down before it's passed TDC