Author Topic: Cold start on recently rebuilt pump?  (Read 6441 times)

October 16, 2009, 03:59:49 am

zozie

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Cold start on recently rebuilt pump?
« on: October 16, 2009, 03:59:49 am »
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

Reply #1October 16, 2009, 06:23:56 am

Doug

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Re: Cold start on recently rebuilt pump?
« Reply #1 on: October 16, 2009, 06:23:56 am »
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.

Reply #2October 16, 2009, 10:34:12 am

zozie

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Re: Cold start on recently rebuilt pump?
« Reply #2 on: October 16, 2009, 10:34:12 am »
Yes it is :-[

Reply #3October 16, 2009, 10:42:59 am

zozie

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Re: Cold start on recently rebuilt pump?
« Reply #3 on: October 16, 2009, 10:42:59 am »
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 ???

Reply #4October 16, 2009, 10:57:49 am

Powered by Spearco

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Re: Cold start on recently rebuilt pump?
« Reply #4 on: October 16, 2009, 10:57:49 am »
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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Reply #5October 16, 2009, 02:20:25 pm

burn_your_money

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Re: Cold start on recently rebuilt pump?
« Reply #5 on: October 16, 2009, 02:20:25 pm »
Is there resistance felt when you pull the cable out and the car is not running?
Tyler

Reply #6October 16, 2009, 06:13:30 pm

zozie

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Re: Cold start on recently rebuilt pump?
« Reply #6 on: October 16, 2009, 06:13:30 pm »
no resistance what so ever....

Reply #7October 16, 2009, 07:50:43 pm

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Re: Cold start on recently rebuilt pump?
« Reply #7 on: October 16, 2009, 07:50:43 pm »
Is the problem you described Libby, fixable with out tearing down the hole pump?
'87 Syncro Transporter Single Cab "Now TDI"
'78 Rabbit..Gas Weekend Racer
'81 Caddy..Diesel 1.6/1.9 TD hybrid 275HP 349TQ "Retired"
'90 MultiVan, 2.5 Suby Swap, Porsche Brakes
'76 Scirocco TD dragster project
'13 Golf R:. Tuned
'98 Puch G320

Reply #8October 18, 2009, 11:19:43 pm

Rabbit TD

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Re: Cold start on recently rebuilt pump?
« Reply #8 on: October 18, 2009, 11:19:43 pm »
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 ???

Reply #9October 19, 2009, 04:38:36 am

burn_your_money

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Re: Cold start on recently rebuilt pump?
« Reply #9 on: October 19, 2009, 04:38:36 am »
  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.
Tyler

Reply #10October 19, 2009, 05:27:18 am

zozie

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Re: Cold start on recently rebuilt pump?
« Reply #10 on: October 19, 2009, 05:27:18 am »
  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.

Reply #11October 23, 2009, 04:33:12 pm

topless96

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Re: Cold start on recently rebuilt pump?
« Reply #11 on: October 23, 2009, 04:33:12 pm »
can over advanced timing make the cold start not respond?

Reply #12October 24, 2009, 03:08:31 pm

burn_your_money

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Re: Cold start on recently rebuilt pump?
« Reply #12 on: October 24, 2009, 03:08:31 pm »
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.
Tyler

Reply #13October 25, 2009, 05:22:57 am

topless96

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Re: Cold start on recently rebuilt pump?
« Reply #13 on: October 25, 2009, 05:22:57 am »
So if I understand what you are saying, a modded pump from Giles would not see cold start response then.
Would that be correct?

Reply #14October 25, 2009, 06:24:37 am

burn_your_money

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Re: Cold start on recently rebuilt pump?
« Reply #14 on: October 25, 2009, 06:24:37 am »
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.
Tyler