VWDiesel.net The IDI, TDI, and mTDI source.

Engine Specific Info and Questions => IDI Engine => Topic started by: TonyTDTruck on May 25, 2012, 06:54:28 pm

Title: AAZ Choke Lever Question
Post by: TonyTDTruck on May 25, 2012, 06:54:28 pm
I had my pump rebuilt by Giles and as we hooked up the choke, I noticed that the choke lever doesn't travel to full choke position. It only travels about one third and then it stops. When you pull the choke handle in the truck, it only comes out about one inch. Is this normal? I have a friend with a 1.6td and the handle on it comes out about 2-1/2".
I'm not sure if this is normal for this pump.
Any input is much appreciated.
Tony
Title: Re: AAZ Choke Lever Question
Post by: Syncroincity on May 25, 2012, 09:23:31 pm
Mine comes out at least 2 inches at full throw, so it's about the same range on the AAZ pump.
What did you use for the cable, an OEM part or something else?
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 25, 2012, 09:41:01 pm
Yes an oem cable. I removed the cable from the pump and used a large screw driver to reach down and move the lever by hand. It only moves about 1/3 the way.
Either it's normal or something is wrong. I will have to wait till I run the engine in a couple of weeks. I can call Giles on Tuesday and ask him as well.
Title: Re: AAZ Choke Lever Question
Post by: rallydiesel on May 25, 2012, 10:51:42 pm
It's not a choke. And the throw is adjustable. Look on the engine side of the pump when the cold-start is pushed in and pushed out. The travel should be limited by the high/low screws. If not, your cable is binding.
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 25, 2012, 11:03:46 pm
Here it is before rebuild. Unfortunately I didn't take a picture after rebuild.
Is it possible to adjust the stops with out removing the pump?
There is very little space between the pump and engine block. >:(

(http://i39.tinypic.com/25hpq40.jpg)
Title: Re: AAZ Choke Lever Question
Post by: ORCoaster on May 25, 2012, 11:57:58 pm
I can never get anything in there to adjust, tighten, loosen or work between the pump and engine.  I just pull the pump and re-time it.  DAS
Title: Re: AAZ Choke Lever Question
Post by: theman53 on May 26, 2012, 02:01:42 am
Mine wouldn't really pull at all unless it was running.
Title: Re: AAZ Choke Lever Question
Post by: bajacalal on May 26, 2012, 02:06:48 am
When I read your first post I wondered if you had turned the motor over, but now it's clear.

Have you tried turning the motor over at all, by hand? Mine will sometimes not engage the cold start advance (it's not a choke, does something totally different than a choke) but will after the motor is running or has at least been cranked.

I'm not sure how exactly it works but I believe there is some sort of cam that has to engage some sort of moving part but will not do so at certain positions without the motor turning.
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 26, 2012, 08:43:58 am
Yes you were correct theman53 and bajacalal ! I used a large screw driver to move the lever and turn the engine slowly by hand and in just 10 deg of rotation the lever moved all the way to open. Good news here.
Okey if it's not a choke, than why is it called a choke cable? The cable is labeled as a choke cable. I go back to the day when choke meant that you grabbed somebody by the neck.
My 61 Ford falcon had a choke. 77 diesel Rabbit 1.6d had a choke.
Just wondering. Anyway, thanks for the help.
This engine will come to life in about a week or so.
Tony
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 26, 2012, 09:01:57 am
While I'm at it. What is this vacuum actuated lever used for? You can see my stubby finger pointing at it and the cable that drives the lever.
And where does this get plugged into?
And on the other side, there is a valve that has a plug for an electrical connector. It looks like a solenoid to open and close a valve.
Does this get a 12v signal from the ignition? And does it stay on 12v while running?
This engine came out of a 94 or 95 Jetta and now it's going into a Transporter that had a 1.6td.
Thanks

(http://i50.tinypic.com/4jxgxw.jpg)
(http://i39.tinypic.com/25hpq40.jpg)
(http://i39.tinypic.com/ao9bls.jpg)
Title: Re: AAZ Choke Lever Question
Post by: theman53 on May 26, 2012, 10:29:08 am
The CS means "cold start" not choke. Gas cars have chokes - restricted air to richen fuel mix. Diesels take 100% air volume that the engine demands...no choke.
Title: Re: AAZ Choke Lever Question
Post by: Syncroincity on May 26, 2012, 05:17:42 pm
Now I think about it, before I had the engine running, the cable did not pull out as far as it does now... So there's some validation to the above idea about something internal to the pump that needs to turn a bit before you see full throw.

The cold start advances the timing... it acts like a choke when it's cold out to ease start-up, but the mechanics of it is nothing like a choke. Your old diesel Rabbit had the same thing you have here.

I don't have that vac actuator on my pump, nor the mechanism that it moves... no idea, sorry.  :P Did yours have the turbo-boost aneroid (the UFO) on top originally, or did Giles have to add it? Mine was a non-fuel enriching pump, I had to have him add the real-deal turbo aneroid to mine (extra $250...) so the pump would respond to turbo boost with more fuel.
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 26, 2012, 05:34:36 pm
Yea it came with that aneroid thingee. And I can't seem to figure out what that vacuum gizmo is. It doesn't talk about it in any book I have.
It looks like a cruise control but not really.
The cold start choke lever, now comes out all the way. Good thing. I almost freaked out.  8)
Title: Re: AAZ Choke Lever Question
Post by: libbydiesel on May 26, 2012, 05:57:56 pm
The reason the cold start is easier to pull at some times rather than others is because it advances the timing by rotating the camplate rollers.  If the camplate is positioned so that the pump is right before or during one of the pressure strokes of the plunger, then by pulling the cold start lever, you will be also pushing the plunger on it's stroke and compressing the plunger return springs.  The cold start should also be noticeably easier to pull when the engine is running because the internal pressure of the pump pushes the timing advance piston in the same direction that the cold start pushes it.
Title: Re: AAZ Choke Lever Question
Post by: Syncroincity on May 27, 2012, 12:15:24 pm
Ah, right, like when you get it back from a rebuild, and it's set at #1 TDC.  ;D
Title: Re: AAZ Choke Lever Question
Post by: R.O.R-2.0 on May 27, 2012, 12:20:04 pm
The CS means "cold start" not choke. Gas cars have chokes - restricted air to richen fuel mix. Diesels take 100% air volume that the engine demands...no choke.

Cold Start Lever is a TIMING ADVANCE (6*)

and not in any way a choke..
Title: Re: AAZ Choke Lever Question
Post by: TonyTDTruck on May 27, 2012, 10:53:00 pm
The reason the cold start is easier to pull at some times rather than others is because it advances the timing by rotating the camplate rollers.  If the camplate is positioned so that the pump is right before or during one of the pressure strokes of the plunger, then by pulling the cold start lever, you will be also pushing the plunger on it's stroke and compressing the plunger return springs.  The cold start should also be noticeably easier to pull when the engine is running because the internal pressure of the pump pushes the timing advance piston in the same direction that the cold start pushes it.

Make sense. So it looks like the best thing to do when starting is to pull the lever as you first turn the ignition key so it pulls without stressing the cable and mechanical links.
Good to know.  :)
Title: Re: AAZ Choke Lever Question
Post by: libbydiesel on May 27, 2012, 11:03:46 pm
Best is actually to pull it before shutdown.  You can actually rev it up a little and it should have almost no resistance.  Second best is pulling while cranking.