VS Shudders under load, Cleaning Idle Jets?

If I read this right, the car only has the problem when in gear? Do you mean while driving or just when you put it in gear and are standing still? Does the car just stutter or hesitate or does the car physically shudder?

Its just driving, its more of a hesitation feels like its running on three cylinders.. When i accelerate it starts missing like its possibly not getting enough fuel. 

How long ago since it was running great?  Has the car been not run for a period of months?  How much gas is in the tank and when was it put in there?

I bought it in September and drove it at least every other day with it running strong with no issues. There was a little flat spot when I stepped on the accelerator but It didn't really bother me as I don't drive it too hard, just to zip around town.  I had just recently topped off the tank before it started running bad.

I cleaned the idle jets and it seems to run a little better but still hesitates when I accelerate. If I accelerate slowly it runs okay but when I step on the throttle it really hesitates/misses. I'm wondering if it could be the accelerate pumps?

Check the diaphragms in the carbs for leaks.

When you cleaned the jets, did you also blow out the recesses in the carb body that the jets screw into with a light blast of carb or brake cleaner? Dirt is often there, not in the jet itself.

If it runs OK at light throttle, but coughs when you step on it, the carb float levels may need to be set. And the fuel pressure supplied by the fuel pump should be checked to see if it's within the pretty narrow range these carbs like.

Sacto Mitch posted:

 

When you cleaned the jets, did you also blow out the recesses in the carb body that the jets screw into with a light blast of carb or brake cleaner? Dirt is often there, not in the jet itself.

If it runs OK at light throttle, but coughs when you step on it, the carb float levels may need to be set. And the fuel pressure supplied by the fuel pump should be checked to see if it's within the pretty narrow range these carbs like.

 

I just cleaned the jets, I will give it a shot.. Thanks

It's not a mechanical cure but I've used in outboards, lawnmowers, and generators - add a bottle of Chevron Techron FI cleaner to gas tank.  It seems to clean out varnish and water that builds up in fuel systems.

I have used the Chevron Techron "Concentrate" with great results, not sure if you used that Greg?

Gary

Sea Foam top end, solved my problems.

Greg, have you looked down the throat, and throttled the linkage, looking for gas from the accelerator jets?

art posted:

Sea Foam top end, solved my problems.

Greg, have you looked down the throat, and throttled the linkage, looking for gas from the accelerator jets?

Thanks, I'll look into the additives...

As far as looking inside the carbs.. I have removed the air cleaners and looked, but I'm not sure what I'm looking for. They look brand new inside. I read something about a squirt of fuel, but I'm not seeing it...  I may not be looking in the right place.. 

Depending on the carbs, mine are Solex/Brosol/Kadron,  looking into the round throat, in the upper area, are there should be a tiny, tiny brass pipe, with its open end pointing down. When you push the throttle a stream of gas shoots out towards the butterfly valve in the bottom of the throat. If this brass jet is plugged up, acceleration will be poor.  Be careful not to drop anything into the throat.  What brand and model # of carb(s) do you have?  

It maybe difficult to get your head directly over the throat, to view the fuel stream. Someone, stepping on the accelerator pedal or moving the linkage can be helpful. (car not running of course). My carbs sit high for some reason, so I needed a hand.

I think I'm going to replace the plugs and spark plug wires even though they appear to be in good order they are 10+ years old. Any recommendations on plugs and wires? I currently have NGK BP5ES-A spark plugs in it now that were original to the car. 

One thing I forgot to mention is that first thing I started with was to replace the fuel filter. 

NGK and Bosch are highly recommended by the gurus on this site (I'm not one of them, a guru that is). 

I use Taylor 8mm wires,  available lots of places.

I believe they are Solex/Kadron 40/44.. They are the stock carbs that VS used in '05, the car is just as it was built by VS, no mods. I'll take a look this evening and see if I can see anything.. 

Thanks

Greg;

In that case, the brass pipe is L shaped, goes out from the throat side and the small leg drops straight down. (Like shower head plumbing. ). As I mentioned it is tiny. On mine the "exit" end of the pipe is cut on the diagonal to direct the spray

When the accelerator is depressed  stream of fuel should come out, on both carbs. Note below the brass pipe, on the left side of the throat about 8:00 oclock

Here's a pic,.

Do you have proper fuel pressure? Tanks screen clogged?

Thanks for the picture!.

I'm not sure how to check the fuel pressure? I know I read its supposed to be around 1.5 psi.. 

PSI gauge. I would check that first as well as the tanks screen.  

Ok, here are my thoughts:  it sounds like classic fuel starvation, which can be caused by any of the following, more or less in order:

1.  Clogged fuel filter

2.  Clogged screen inside of the tank ( remove the fuel outlet assembly from the bottom of the tank to access it - Drain the tank first!) or clogged screen where the fuel enters the first carb (if both are daisy-chained for fuel)

3.  A partially-collapsed rubber fuel line, restricting flow

4.  Weak or mis-adjusted fuel pump - remove a fuel line from a carburetor and crank the engine over to see if you have a lotnof fuel coming out of the line

5.  Percolation of fuel in the fuel line if it is run too close to a heat source (exhaust pipe) - but this usually only affects start-ups, not normal run time.

Other things to rule out:

6.  Weak spark due to poor coil, coil wire, distributor cap or open rotor

Some of these have been covered already so if you've done everything mentioned in this entire thread with no improvement, it's time to seek competent help.

Thanks Gordon, 

I will go through the list when I can take another crack at it, probably not until Tuesday as well as replace the plugs, wires and set the statice timing.  I don't currently have a timing light.

When I replaced the fuel filter there was a solid stream of fuel shooting out so I doubt I have a clogged screen at the tank. 

. 

Thanks Gordon,  my 2006 VS 1915 with 10K miles has been exhibiting very similar symptoms.  Greg, let us know if you find the culprit.

Hi Tom, 

I will, please let me know if you have any luck on your end. Its a real bummer we have been having some very nice speedster weather here.. 

Will do, Greg.  Mine is still very drivable.  Stumbling occurs primarily when re-accelerating while in motion.  From standstill starts not so much.

Greg,  you have kadrons. You must have a fuel pressure regulator. Set it at 1.5 or 1.75 psi. Your main jet may be to small. Check the color of the plugs. 

Have you checked # 6 yet?

Your problem is simple, 11 years old with 1300 miles. This baby needs to be driven. 

Anthony posted:

Greg,  you have kadrons. You must have a fuel pressure regulator. Set it at 1.5 or 1.75 psi. Your main jet may be to small. Check the color of the plugs. 

I haven't checked the pressure yet, but I did check the main jet which wasn't clogged an looked brand new. If I read it correctly it was #130. Not sure what size I should be running? 

crhemi (Bill) posted:

Have you checked # 6 yet?

I checked the distributor and It appears to be in good order looks brand new. How would I check the condition of the coil? Visually it also looks brand new.

If it truly only has 1300 miles in 11 years then MAJORKAHUNA's suggestion is not unreasonable.  Depending on how long it's been sitting and how old the gas is you might have a bunch of gunk in the fuel system.  Carb jets, floats, fuel lines, fuel filters, and  the tank itself are suspect.

What the Fetch posted:

Anthony posted:

Greg,  you have kadrons. You must have a fuel pressure regulator. Set it at 1.5 or 1.75 psi. Your main jet may be to small. Check the color of the plugs. 

I haven't checked the pressure yet, but I did check the main jet which wasn't clogged an looked brand new. If I read it correctly it was #130. Not sure what size I should be running? 

Thinking about it in my head with the info provided, it may be your accelerator pump adjustment is off. This isn't a difficult task, but requires some pateintance. Call me and I will explain it. 1-916-255-7996 of go to kaddyshack web site and download their running guide.

majorkahuna posted:

Your problem is simple, 11 years old with 1300 miles. This baby needs to be driven. 

 

Trust me, I wish I could drive it. Before this issue surfaced I was driving it almost daily I put 800 miles on it in the short time I've owned it.

Its just tough for me to find the time to sort it out. I'm in the golf business and in the middle of our peak season. I'm lucky if I can get in the garage once a week. It also happens to be perfect weather for driving. If anyone knows a good air-cooled mechanic in the Palm Springs Ca. area I'm ready to have a professional take a look at it. 

It's common for carburetor issues to be over complicated. Here are the steps I use for your situation, I have many years of carburetor experience on VW engines.

1- Remove all of the idle jet assemblies from the carbs. Also, remove all of the mixture screws making sure you do not loose any springs or O rings.

2- blow out with compressed air all of the idle jets, hold them up to a light to make sure they are not plugged. Blow through the mixture screw hole being careful to not let gas blow into your face lol. Also blow through the idle jet passage.

3- install all of the idle jet assemblies. Install the mixture screws and GENTLY bottom them out. Once you feel that they have bottomed out, back them out 2 turns. When I say gently bottom them out, I mean GENTLY. You can damage the carb if you turn them in too tight.

 4- Remove the heim joints from each carb. This is to prevent one side from holding the other side open from improper adjustment.

5- Start the car and get some heat in the engine. Using an air flow meter, you need to buy one if you don't have it already, adjust the idle speed stops on the carbs so they are pulling the same amount of air at idle.

6- Turn each mixture screw in very slowly until you hear that particular cylinder go lean and stop firing. At this exact spot, stop and turn the mixture screw out until you hear the cylinder firing again. Do this to all of the mixture screws.

7- Using your airflow meter. Adjust each idle speed stop to your preferred rpm, I like 950-1000 rpms at idle for most engines.

8- Follow step #6 one more time because every time you adjust idle speed, you effect idle air fuel ratio. It might be necessary to slow the idle speed back down 2 or 3 times and adjust the mixture screws 2 or 3 times until you get things dialed in.

9- Most dual throat carbs have a air bypass screw to adjust throat to throat on the carburetor. Make sure both bypass screws are bottomed out before adjusting. Using your airflow meter, determine what throat is pulling less air. Adjust that bypass screw so it is pulling the same amount of air. Do this to both carburetors. Follow steps #6 and #7 after doing this adjustment because your idle speed and idle air fuel ratio will be effected.

10- the final step is to re install the heim joints and adjust them so both carbs are opening at the exact same time. You want to make sure this adjustment is perfect or one carb will lead the other and the engine will accelerate poorly.

This all may sound difficult but it just takes practice. You will mess up, I guarantee it but hang in there. This all just takes practice. 

The Gospel according to Downs.  Great summary.  I have copied and printed it out. I assume the Great Weber guru Mr. D. Piperato, Esq. would approve.  I have a little throat air flow imbalance, and have yet to fiddle w/ the by-pass thingies.  Might have to screw up my courage (pun intended) and have at those next time around.

I do have a question, however.  Supposing all is jake except that on one throat, screwing in the mixture valve has basically no effect on engine speed.  What is the reason for that?  And if the idle jet there is as clean as a whistle?  A clog inside the carb, despite having blasted the crap out of it with carb cleaner eight ways to Sunday?.  What then??

1- .......making sure you do not loose any springs or O rings.

AKA - Little brass thingies.

Nice post pat. 

By now with everyone's input the carbs could have been rebuilt and adjusted several times ��

Thanks Pat, I really appreciate the information! I'm going to give it a go when I can get back in the garage. 

I did check the valves and they were extremely tight. I set them to .006 and it is idling stronger and seems to run better but there is still a hesitation when I step on the throttle. The hesitation definitely isn't as bad as it was, but its still there. 

I'm back to the distributor. What are you using?

I believe its the 009. 

I ordered a new coil. From what I've read, I'm looking for a blue spark and it was orange when I tested it.