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Mon Jun 16, 2008 5:30 pm

71 Super. I just installed my new engine and can't get it set up right. Stock 1600 DP with a mild cam. Very new stock replacement carb. Valves right on. Engine timing correct.

Roughly set up the carb according to procedure. Started at 3 turns out on the mixture screw. Hardly keep running. Bypass screw little to no effect.

I can't get it to run smooth unless I way advance the distributor and wind out the mixture screw several turns.

I have the dual vacuum port dist. and the pulley with the notch to the left of the dimple. ( the dimple is on the outer/rear most part of the pulley) I've checked the pulley marks and they jive with TDC.

I've already run in the cam. I've gone step-by-step but can't seem to get it right.

This car was very messed up before I started.

What the heck???!!! Thanks.

Mon Jun 16, 2008 7:12 pm

Look for vacuum leaks...base of carb, intake manifold center boots, missing vacuum plugs, leaky vacuum hoses, base of manifold castings where they meet the head...

Mon Jun 16, 2008 8:35 pm

mnussbau wrote: Look for vacuum leaks...base of carb, intake manifold center boots, missing vacuum plugs, leaky vacuum hoses, base of manifold castings where they meet the head...

X2, If you used the metal gaskets at the end castings, they are a crush type gasket. When torquing down the nuts you need to do it evenly or you will get a vacuum leak, same for the carb. Pat

Mon Jun 16, 2008 8:52 pm

another possibility is that the new carb may be junk. Sounds harsh, but I've heard a lot of horror stories of new import carbs that won't run or adjust right out of the box....

Tue Jun 17, 2008 1:17 pm

Thanks for your responses.

I found that both sides of the distributor advance pod are leaking badly.

I'll start there.....

Fri Jul 04, 2008 3:37 pm

2 weeks later....

I've installed a new Dist can. Dies instantly if I plug the carb, so I assume no more vacuum leaks.

Not ruling out a bad new carb yet.

Pretty much the same condition. Won't run unless it's way advanced ( 20 degrees) and idle screw way out.

Don't want to drive it that far advanced, but it sure sounds nice. Of course I know it's not right.

Any more ideas?

Thanks.

Fri Jul 04, 2008 3:59 pm

ts88 wrote: mnussbau wrote: Look for vacuum leaks...base of carb, intake manifold center boots, missing vacuum plugs, leaky vacuum hoses, base of manifold castings where they meet the head...

X2, If you used the metal gaskets at the end castings, they are a crush type gasket. When torquing down the nuts you need to do it evenly or you will get a vacuum leak, same for the carb. Pat
Didnt you do this?

Fri Jul 04, 2008 4:19 pm

This sounds eerily like the problems I had with my Super when I first got it.

I bought it right before moving, and so for the cross-country drive, I had a mechanic that I trusted give it a once-over to make sure it was Ok to drive the 500 miles. Once in my new home, I started to work through the various problems. Lots of things associated with dirty carbs.

One thing I found when I put a degree pulley on the back of the cam was that the timing was set to about 20 degrees BTC--way too far advanced. As time went on, i finally decided that I had an induction leak, and one suspect place is around the bushings on the throttle.

So I bought another carb on ebay, and things were VASTLY improved. I also found that the mixture screw on the old carb had been turned out very far. I think basically I had a really big leak AFTER or IN the carb, and so the engine was running really lean. The timing had to be advanced to make it run right.

Dies instantly if I plug the carb, so I assume no more vacuum leaks.

I wouldn't assume that at all.

One of the things I found for searching for induction leaks was to use starter fluid. With the engine warmed up and at idle (throttle closed/maximum vacuum in the maifold) you squirt starter fluid near all the possible openings. Around the base of the carb by the throttle shaft. Around the flange where the carb bolts to the manifold. Where the center manifold section joins the side sections at the rubber boots. As much as you can where the manifold end pieces meet the heads (you sort of have to squirt down around the tin for this). If the engine INCREASES in rpm (you can hear it) when you squirt starter fluid at any of those places, then you have a leak there.

Other things to check without tearing stuff apart:
- what carburetor is it? 34PICT-3? Is it German or Brazillian? (this is on the left side of the float bowl).
- Have you plugged or connected ALL of the vacuum ports on the carb? On the brazillian one I have, there are TWO around the middle body, above the throttle.

The one pointing left and another pointing at you when you're looking at the engine. On mine, I have the port on the LEFT going to the distributor advance, the one pointing at me is plugged.

On the German-made 34PICT-3 I have, there are THREE vacuum ports. Two around the middle of the carb and one at the base, next to the mounting screw. I believe that the one at the base is supposed to go to the retard side of the distributor can, but I'm not 100% sure about that.

Check the usual things. Make sure the choke is opeing all the way. Take off the air cleaner (engine warm but off) and look. Check to see if someone has filled in the hole in the throttle plate. (It should have a round hole).

I'm a bit concerned that the bypass screw doesn't effect the idle speed. If you turn it all the way in, then if everything else is working, the car should STOP. That should be the only air supply to the engine at that point, because the throttle plate is basically closed hard. When the engine's idling, try disconnecting the wire to the idle cut-off solenoid. The engine should stop cold.

Did you set the screw on the throttle arm that seats against the fast idle cam? Car warm, just until it first touches then 1/4 of a turn, if I remember correctly.

If none of this leads you in a useful direction, then I'm afraid my suspicion is that something's wrong with the carb, and you're going to have to tear it apart and check and clean things.

Sorry for the long post, but I hope something here helps.

Fri Jul 04, 2008 4:35 pm

have u checked to make sure the cut-off solenoid is working?

Fri Jul 04, 2008 5:08 pm

gevmage wrote: On the German-made 34PICT-3 I have, there are THREE vacuum ports. Two around the middle of the carb and one at the base, next to the mounting screw. I believe that the one at the base is supposed to go to the retard side of the distributor can, but I'm not 100% sure about that.
Not sure about all possible variations of the 34 Pict 3, but on mine the port at the base that points toward the back is for the EGR valve.

Another possibility for the bypass screw having no affect, and this is admittedly slight, is the throttle cable might be too tight. I had this problem twice on my convertible...seems I had pulled the cable too tight when installing the barrel nut, which basically prevented the throttle plate from closing. No adjustments on the carb did anything. Had me talking to myself the first time it happened, for about 20 minutes, until I figured out what happened. The second time it happened I fixed it in a minute!

Fri Jul 04, 2008 6:55 pm

Thanks for the tips guys...

I checked for vacuum leaks, couldn't find any. The intake has been replaced/re-sealed recently.

The carb is a new Kafer 34 Pict 3. High quality Brazilian I figure :(

All vacuum ports are connected. Throttle arm screw touches + 1/4 turn. Choke fully opens. Cut-off solenoid OK. Throttle cable tension OK.

I just picked up some carb. cleaner and I'm going to rebuild the original German carb that came with the car. We'll see what happens tomorrow.

This is the cars troubled history as far as I know. The previous owner had a running problem. Dicked around with it, threw tune-up parts at it. Then he installed the new Kafer carb. Still no good so he installed a 009 dist. and that made it worse he said. Keep in mind he didn't know what he was doing so anything is possible.

So he reinstalled the original dual vac. distributor (with the blown vac. can)

Then I bought it. The engine was tired so I rebuilt it. Now I'm dealing with his original issues.

It is possible that the leaking distributor vac. can was the only problem and then he installed a crap carb. That would be nice. I thought I had this figured out when I found the bad vac leak at the distributor.

So.... New used carb tomorrow.

Thanks again

Fri Jul 04, 2008 9:31 pm

I had one that right under the carb on the fatest part of the intake where the heat riser tubes come up the heat riser tubes had rusted through and had started burning a hole into the intake itself. The only way i found it was i turned the lights off in the garage to set the timing and the strobe light was coming through the top of the carb very lightly but enough to catch my eye. I replaced the intake and it ran like a dream,

Fri Jul 04, 2008 10:06 pm

This really does sound like my car. LOL I have 72 super w/34 PIC. I have a gas leak coming from the shaft of the butterfly valve after shutting off motor. I am going to use the starting fluid technique to see if it has vacuum loss there. Is there a original setting for the bypass screw? And with that leak where it is, do I need new carb or can that be fixed? I did a carb rebuild (new gaskets and screws).

Sat Jul 05, 2008 5:06 am

veedubbug wrote: This really does sound like my car. LOL I have 72 super w/34 PIC. I have a gas leak coming from the shaft of the butterfly valve after shutting off motor. I am going to use the starting fluid technique to see if it has vacuum loss there. Is there a original setting for the bypass screw? And with that leak where it is, do I need new carb or can that be fixed? I did a carb rebuild (new gaskets and screws).
When you mean "original setting", I assume you are asking if there is a starting point for setting the carb. If so, you screw it all the way in, then back it out about 2-1/2 turns. Same number of turns as the volume control screw. That'll get you running, then you need to adjust. This is a good discussion on setting the carb.
http://www.vw-resource.com/34pict3.html

On the throttle shaft leak, yes, they can be rebushed. I'm having Keifernet rebuild a used 34 I picked up as we speak.
http://www.thesamba.com/vw/classifieds/detail.php?id=495640

Sat Jul 05, 2008 7:39 am

Quote: I checked for vacuum leaks, couldn't find any. The intake has been replaced/re-sealed recently.
You checked for vacuum leaks since replacing the intake? If not, then that's the most likely place.

Quote: Throttle cable tension OK.
Er...throttle cable should be slightly loose with the throttle closed, right? That way the throttle closes all the day? I don't remember seeing a check or a specification for this.

Quote: I just picked up some carb. cleaner and I'm going to rebuild the original German carb that came with the car. We'll see what happens tomorrow.
Once you do so, check for vacuum leaks again with the starter fluid.

Sat Jul 05, 2008 11:07 am

No luck with the orig carb rebuild. Too much shaft slop. Reinstalled new Kafer carb. Throttle cable not too tight.

I'll check for vacuum leaks again. It does seem like a vacuum leak.

I did take if for a spin today. No pinging heard and it didn't seem to be running hot while being over advanced.

It has new rings and I'm a bit worried about them seating with all this screwing around in the garage.

Sat Jul 05, 2008 11:31 am

ok what kind of gaskets are you using for the intake end castings? How about the boots? Dont you have gasket at the carb base? Also i wonder what kind of distributor you are using and where are you setting it at?

Sat Jul 05, 2008 1:13 pm

Brett Ross wrote: ok what kind of gaskets are you using for the intake end castings? How about the boots? Dont you have gasket at the carb base? Also i wonder what kind of distributor you are using and where are you setting it at?

New orange rubber boots and metal multi layer end gaskets. Paper carb gasket.

Stock dual vac distributor.

I can't get it to idle unless it's advanced at least 20-25 degrees BTDC. Idle mixture screw out several turns. If I retard it it starts to run like crap. I have the 7 degree BTDC pulley. I'm trying to set it per spec with the dist. hoses connected.

It's really annoying because it seems like a vacuum leak but I can't find one. This is how the prev. owner had it set up as well. Since then I've changed the intake, the leaking vacuum pod on the dist. and redid the engine.

Sat Jul 05, 2008 5:40 pm

It sounds like you've done a lot of stuff that hasn't made a difference. When that happens to me (often), I often find that I'm missing something fundamental.

Where do you have the vacuum hoses from the dizzy connected? I'm not absolutely sure about this, but I think the retard side should be connected to a vacuum port BELOW the throttle on the carb (so it's active when the engine is at idle). The advance side of the can should be connected to a vacuum port ABOVE the throttle, so that it becomes active when the throttle opens.

You originally said that you have an original pulley from that car, right, not a degree pulley? How are you measuring degrees ahead of TDC? What did you use for your reference for TDC? I seem to remember that the notch on the original pulleys for a car designed to use the dual-can dizzy was at 5 degrees ATDC.

Also--my experience altering the timing of the engine was that timing advance and the two idle screws all strong effect each other. If you move the timing, you have to adjust both idle screws again to get the engine back to running right. To move the timing a long way, you probably have to move it a little and then re-set the idle multiple times or else the engine will stop running.

Sat Jul 05, 2008 6:55 pm

I have a adjustable advance timing light. I am using the stock 5 deg ATDC pulley.

Your correct about the 2 hoses and I do have them on correctly.

I'll try it again tomorrow.

I wonder what is typical as far as the number of turns out of the mixture and bypass screrws...

Thanks everyone for your input.