TheSamba.com :: View topic - my idle problem has returned with the cold weather!

Tue Nov 03, 2009 9:24 pm

Okay, so my idle problem has returned. It will die the first few stops down the road until the engine is warmed up. I've tuned my carb with this site: http://www.vw-resource.com/34pict3.html

I replaced my muffler with a new none holy one and my cold idle was under control during the summer. When I say under control, I mean it only stalled the first stop sign down the road.

Now that it is getting colder out it runs absolutely terrible for the first few stops in the morning until it gets warmer. In the middle of the day its not as bad, but it still stalls until the engine is warm.

I've adjusted the choke a bunch of times since its been colder out and that doesn't seem to help it at all, it will still die the first few stops down the road. I've also been reading a bunch of threads and scouring the vw resource website and I can't figure out why it keeps dying on me when its really cold.

I have an aftermarket air filter on my carb, no air cleaner/oil bath or charcoal canister. I can take some pictures if that helps any.
I admit that I haven't adjusted the valves since the spring, so maybe that could be a problem but I don't know. It feels like whenever I think I've got it figured out...it will work wonderfully for that day and the next day it will be up to the same old tricks.

I don't really know what to check anymore. I'm not very mechanically inclined and this is my first vehicle. Any help or suggestions or maybe a beer would be great. I can also take pictures if that helps anything. Help!

Tue Nov 03, 2009 10:12 pm

You may have to tweak the basic choke adjustment, the choke unloader, and/or the fast idle adjustment. At the point in time that the engine is dying what happens when you remove the air cleaner and access the choke butterfly. Try opening it a little or closing it a little with your fingers and see which makes it run better.

What temperature is your intake manifold when the engine is wanting to stall? If you are getting ice on the outside you are definitely getting ice built up on the inside.

Tue Nov 03, 2009 11:01 pm

The weather around here has been ideal for carb ice the last few days.

You really need a stock filter with the preheat to fix that, making sure the tubes across the bottom of the manifold are clear and getting hot will help alot too.

Wed Nov 04, 2009 8:21 am

I second the heat for the carb. Easiest way is a hose to the air filter from the back of the motor the way they did it from the factory. They put a hole in the tin directly behind where the cooling air comes out of the cylinder area, and right on top of the muffler. This supplied heated air to the air filter.

It would help if you told us what kind of carb, motor etc. Please don't say you told us in a previous post. I have a hard time remembering what is in my own vehicles never mind what everyone else drives.

If it is a stock 1600 you can just get a stock air filter and hose. While you are at it check if the manifold heat is working. Drive a few miles and feel the small tube under the intake manifold. It should be hot. If not it is probably plugged up. It should be taken off and cleaned out, not an easy job.

Wed Nov 04, 2009 8:30 am

busdaddy wrote: The weather around here has been ideal for carb ice the last few days.

You really need a stock filter with the preheat to fix that, making sure the tubes across the bottom of the manifold are clear and getting hot will help alot too.

Tell me about it!! It takes quite a few tries to even start my bus up! Once started though, it takes just only about 2 minutes to tick over nicely. But that hard starting surely isn't good for the starter :? Then again, I have dual ICTs and the car is indoors. What's your setup skid?

Wed Nov 04, 2009 8:35 am

skid wrote: Okay, so my idle problem has returned. It will die the first few stops down the road until the engine is warmed up.

You need to learn how to drop it neutral and brake with your left foot...so you can keep up the revs and it won't stall. Years of driving 10/13 speed trucks will help you master this move. :wink:

Wed Nov 04, 2009 8:37 am

skid wrote: I've tuned my carb with this site: http://www.vw-resource.com/34pict3.html

Quote: _________________
'71 pop top westy

Wed Nov 04, 2009 9:08 am

skid wrote: I replaced my muffler with a new none holy one and my cold idle was under control during the summer. When I say under control, I mean it only stalled the first stop sign down the road.

When you say muffler are you talking a set of aftermarket headers? Many headers are not drilled for the heat risers and on others the holes needs to be enlarged.

Wed Nov 04, 2009 11:25 am

Quote: The weather around here has been ideal for carb ice the last few days.

You really need a stock filter with the preheat to fix that, making sure the tubes across the bottom of the manifold are clear and getting hot will help alot too.

Cool, I had a feeling that would help. Its now on my list of parts that I need.

Quote: What temperature is your intake manifold when the engine is wanting to stall? If you are getting ice on the outside you are definitely getting ice built up on the inside.

When it first stalled this morning I jumped out and felt the intake manifold. The smaller tube on the right was pretty warm, the one on the left was not as warm as the right one and in the middle was as cold as it would be if I hadn't even started it. I haven't tried the other things you mentioned yet.

Wildthings wrote: skid wrote: I replaced my muffler with a new none holy one and my cold idle was under control during the summer. When I say under control, I mean it only stalled the first stop sign down the road.

When you say muffler are you talking a set of aftermarket headers? Many headers are not drilled for the heat risers and on others the holes needs to be enlarged.

I have aftermarket headers, but in the summer I pulled it out (while getting attacked by engine spiders) and we drilled holes in the flanges because they were not drilled. That was what improved my idle problem for the summer. When I say muffler, I mean I had to get a new muffler cause the old one was mostly holes. I have a bugpack single quiet pack muffler.

Quote: skid wrote:
Okay, so my idle problem has returned. It will die the first few stops down the road until the engine is warmed up.

You need to learn how to drop it neutral and brake with your left foot...so you can keep up the revs and it won't stall. Years of driving 10/13 speed trucks will help you master this move. Wink

I totally have something like that mastered right now, but definitely not as smooth! ;)

Wed Nov 04, 2009 1:38 pm

With the engine cold you loosen the screws on the carb element and rotate it until the choke just barely closes. If you poke it with a screw driver or your finger it and let go it will end up somewhere between fully closed and about 1/8" open. Then you tighten the three screws.

Next you start the bus and warm it up. You put the idle stop on the specified tooth of the fast idle cam, from memory the 2nd tooth, maybe 3rd. Bentley will have it. With a tachometer you adjust the idle speed to the sprecified rpm - I believe it will be around 1600 to 1700 RPM, again Bentley will have that number.

You then rev the engine, let go and count how many seconds it takes to return to idle. If it is more or less you adjust the idle return to the specified time. If there is a dashpot you adjust the clearance to the specified amount.

When those are done you drive it in the morning. If the choke warms up too fast you add a tiny bit of tension. If it warms up too slow then you release the tension a tiny bit. While VW does not specify summer and winter settings, I found that a little more tension in the winter helped it when cold and a little less in summer helped it there.

You must also make sure that the choke opens from the electricity.

Last - if you are warming the bus and smoking a joint, cigarette or listening to a song before you leave - stop that. You need to drive the bus off within 5 to 10 seconds of starting it. Otherwise the 12V applied to the choke opens it while you are sitting and the engine is still cold when you drive off - but you have no closed choke so it dies.

Wed Nov 04, 2009 1:48 pm

Operational fanshroud flaps and a functional thermostat hook-up will REALLY help in addition to making sure that your pre-heat manifold pipes are clear.

Wed Nov 04, 2009 1:54 pm

I second all the preheat / manifold / choke adjustment comments, but would like to add a third comment.

At Keifernet's suggestion I looked at my idle jet. This is sometimes as symptom of a clogged jet, as it can't deliver enough fuel when cold.

He also suggests that years of tightening the jet wears them too deep into the body of the carb. You may get great results by backing the jet out slightly as you're tuning it - you may find a sweet spot where the idle jumps up. If so, locktite the jet in place, then readjust the carbs other settings.

I did this with my dad's '69 and later my Speedster when it was running a 34-pict-3. After dealing with a season of stalling and fancy footwork, this was a great solution.

A properly adjusted carb should start in any weather and fast idle unitl it is warmed up, regardless of how many starts and stops you make...

Wed Nov 04, 2009 2:45 pm

SGKent wrote: With the engine cold you loosen the screws on the carb element and rotate it until the choke just barely closes. If you poke it with a screw driver or your finger it and let go it will end up somewhere between fully closed and about 1/8" open. Then you tighten the three screws.

Next you start the bus and warm it up. You put the idle stop on the specified tooth of the fast idle cam, from memory the 2nd tooth, maybe 3rd. Bentley will have it. With a tachometer you adjust the idle speed to the sprecified rpm - I believe it will be around 1600 to 1700 RPM, again Bentley will have that number.

You then rev the engine, let go and count how many seconds it takes to return to idle. If it is more or less you adjust the idle return to the specified time. If there is a dashpot you adjust the clearance to the specified amount.

When those are done you drive it in the morning. If the choke warms up too fast you add a tiny bit of tension. If it warms up too slow then you release the tension a tiny bit. While VW does not specify summer and winter settings, I found that a little more tension in the winter helped it when cold and a little less in summer helped it there.

You must also make sure that the choke opens from the electricity.

Last - if you are warming the bus and smoking a joint, cigarette or listening to a song before you leave - stop that. You need to drive the bus off within 5 to 10 seconds of starting it. Otherwise the 12V applied to the choke opens it while you are sitting and the engine is still cold when you drive off - but you have no closed choke so it dies.

Cool, I'll try this out when I get a hold of a tachometer. I don't have my own, I just borrow my boyfriend's. I'll also stop warming the bus, I was starting to notice that it was doing more harm than good cause it would just start to die a lot while I was just sitting there.

Quote: Operational fanshroud flaps and a functional thermostat hook-up will REALLY help

I was looking into this yesterday, but I didn't end up figuring out if I had them or not. Also, the preheat manifold looked pretty clear when we pulled it off in the summer. This stuff is all pretty new(like not even a year old) so I'd be surprised if it was full of gunk already.

Thanks for all the suggestions guys! I mostly have no idea what I am doing but I'll try. I should mention that my carb is not a nice german carb, but its a new Empi carb(again, less than a year old). So maybe this is making my problem even worse that it is?

Thu Dec 31, 2009 3:40 pm

So an update is in order here. I tuned up the bus last month and the old man is behaving. If I baby my stops he doesn't die anymore at first few stops when cold. However, I am in the process of hooking up the stock air cleaner/oil bath and I've come across some predicaments.

Is there a place where I can I temporarily hook up my brake booster to the stock air cleaner until I locate a proper intake manifold for my year? I'd like to avoid a larger right leg.

Since I'll have the stock oil bath hooked up should I keep my extra oil filter? Or at this point would it just be silly/useless/annoying to have?

Also, I don't have this little doodad:

Is this absolutely necessary? I'm betting it is but I thought I'd ask anyway.
:D

Thu Dec 31, 2009 5:33 pm

OK, I'm a bit confused and you may be too.

The brake booster line connects to the manifold, connecting it to the aircleaner will do nothing for your brakes but will keep the end of the hose clean inside, there is no manifold vacuum upstream of the carb throttle plate.

Which extra oil filter? If it's an external filter you should likely keep it if it's installed and working now. An oil bath air filter does nothing for your engine oil, 2 completely separate systems.

As for the oil filler/breather you don't have anything? or don't have the one with the draft tube running down beside the dipstick? If it's the one with no draft tube it's likely for a 74+ Beetle (or Euro bus) and has the large breather tube sicking out by the filler cap. You'll have to adapt it down to connect to the tube on the filter snout, JB weld and progressively smaller tubes work for this, just don't let the tube fall into the breather before it sets.
If your engine is worn and making alot of blowby you may develop a leak around the pulley though, if it is find an earlier filler with the draft tube.

Thu Dec 31, 2009 7:00 pm

busdaddy wrote: OK, I'm a bit confused and you may be too.

The brake booster line connects to the manifold, connecting it to the aircleaner will do nothing for your brakes but will keep the end of the hose clean inside, there is no manifold vacuum upstream of the carb throttle plate.

Okay, so maybe I was a little confused but I think I got it now. So basically I don't have any vaccum going to my booster right now, as its connected to the aftermarket air cleaner. Huh. I guess I am getting that stronger right leg!

Quote:
Which extra oil filter? If it's an external filter you should likely keep it if it's installed and working now.

Oohhh okay. Was confused about that whole setup entirely I guess. I've got an external filter mounted to the spare tire well. I won't remove it then.

Quote: As for the oil filler/breather you don't have anything? or don't have the one with the draft tube running down beside the dipstick? If it's the one with no draft tube it's likely for a 74+ Beetle (or Euro bus) and has the large breather tube sicking out by the filler cap. You'll have to adapt it down to connect to the tube on the filter snout, JB weld and progressively smaller tubes work for this, just don't let the tube fall into the breather before it sets.

I just don't have one with the draft tube running down beside the dipstick. Its just the filler with a large breather coming out of it. What exactly is it supposed to connect to when it leaves the tin?

Quote: If your engine is worn and making alot of blowby you may develop a leak around the pulley though, if it is find an earlier filler with the draft tube.

Blowby?!

My oil filler looks like this:
http://www.cip1.ca/ProductDetails.asp?ProductCode=ACC-C10-5374

Thu Dec 31, 2009 7:07 pm

skid wrote:
My oil filler looks like this:
http://www.cip1.ca/ProductDetails.asp?ProductCode=ACC-C10-5374
Ohhhh......OK, that will work, connect a short hose between the nipple on it to the nipple on the snout of the air filter, if you have a charcoal canister connect it's line to the nipple on the side of the filter body, if you don't have charcoal plug the nipple on the side of the filter.

Blowby is combustion gasses escaping past the rings into the crankcase when the rings are getting worn, if you don't have enough crankcase ventilation it'll find another way out, usually where the pulley meets the case. If your engine is healthy don't worry.

Thu Dec 31, 2009 7:10 pm

busdaddy wrote: skid wrote:
My oil filler looks like this:
http://www.cip1.ca/ProductDetails.asp?ProductCode=ACC-C10-5374
Ohhhh......OK, that will work, connect a short hose between the nipple on it to the nipple on the snout of the air filter, if you have a charcoal canister connect it's line to the nipple on the side of the filter body, if you don't have charcoal plug the nipple on the side of the filter.

Ok, I have the hoses for that already and the charcoal. I just gotta hook it up. What should I do with the hole that will be in the tin that's for the draft tube? Just plug it up?

Thu Dec 31, 2009 7:17 pm

Yep, a bit of sheet metal and a screw would be best.

Thu Dec 31, 2009 7:19 pm

Cool, thanks! :)