Author |
Message |
Volkie1 Samba Member
Joined: September 01, 2018 Posts: 39
|
Posted: Sun Oct 21, 2018 1:14 am Post subject: Intermittent cut out after acceleration |
|
|
I'm finding that if I rev high and have to come to a stop so for example getting caught out by a red light the big will sometimes stifle, bog Down and cut out. The ignition system starts the bug every day on the first spark. Any ideas what it could be I need by Bug running right |
|
Back to top |
|
|
smitty24 Samba Member
Joined: April 28, 2008 Posts: 2723 Location: Salem, Oregon
|
Posted: Sun Oct 21, 2018 9:23 am Post subject: Re: Intermittent cut out after acceleration |
|
|
Have you gone through the basics with the fuel system? Correct jets that are clean and no debris in carb passageways? Idle speed good? No vacuum leaks. |
|
Back to top |
|
|
bluebus86 Banned
Joined: September 02, 2010 Posts: 11075
|
Posted: Sun Oct 21, 2018 9:45 am Post subject: Re: Intermittent cut out after acceleration |
|
|
yes, a basic carb tuning, maybe even disassembly and clean maybe needed. of course before carb tuning, assure no manifold vacuum leaks, test with flammable carbcleaner spray when at idle, squirt cleaner at each manifold joint if idle speed changes, there is a leak at that spot. also get a timing light and check timing and advance, retard operatio .
also assure valves are adjusted prior to carb tuning.
Good luck, let us know how it goes.
Bug On! _________________ Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
|
Back to top |
|
|
mukluk Samba Member
Joined: October 18, 2012 Posts: 7028 Location: Clyde, TX
|
Posted: Sun Oct 21, 2018 2:03 pm Post subject: Re: Intermittent cut out after acceleration |
|
|
Having the engine die when you slow or stop abruptly is due to an overly rich idle mixture. Try incrementally turning the volume screw in a quarter to half a turn with a test drive between adjustments. If leaning the mixture via the volume control screw doesn't fix it, your jetting is too large. _________________ 1960 Ragtop w/Semaphores "Inga" |
|
Back to top |
|
|
scottyrocks Samba Member
Joined: August 19, 2016 Posts: 2664 Location: Long Island, NY
|
Posted: Sun Oct 21, 2018 2:16 pm Post subject: Re: Intermittent cut out after acceleration |
|
|
mukluk wrote: |
Having the engine die when you slow or stop abruptly is due to an overly rich idle mixture. Try incrementally turning the volume screw in a quarter to half a turn with a test drive between adjustments. If leaning the mixture via the volume control screw doesn't fix it, your jetting is too large. |
If I'm not mistaken, the volume screw is an air adjustment, so you want to turn it left/counterclockwise/out to lean the mixture.
As a baseline, before the test drive, start the car and while it is idling, turn the screw clockwise until the engine starts to slow. Then turn it back clockwise about 1/4 to 1/3 turn. The idle will pick up. If it is too fast, then adjust the idle speed screw that contacts the toothed cam that controls the high speed idle.
Your mixture will now be in the correct range for you to begin the test drives, if even needed. Your mixture may be too rich if the volume control is screwed too far in right now. _________________ “If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch' |
|
Back to top |
|
|
mukluk Samba Member
Joined: October 18, 2012 Posts: 7028 Location: Clyde, TX
|
Posted: Sun Oct 21, 2018 2:30 pm Post subject: Re: Intermittent cut out after acceleration |
|
|
scottyrocks wrote: |
If I'm not mistaken, the volume screw is an air adjustment, so you want to turn it left/counterclockwise/out to lean the mixture.
|
You are mistaken. The volume control screw controls the volume of a fuel/air mixture (dictated by the size of the idle jet) allowed to pass into the carb throat and mix with the incoming air -- in effect it is more so controlling the total amount of fuel permitted in than it is the amount of air. Turning the volume control screw in will adjust the fuel/air mixture passing into the airstream through the carb, but only up to a point. Think of the carb idle jet size as the rough adjustment and the volume control screw the fine adjustment of the idle mixture.
A decent read if you're interested:
https://www.thesamba.com/vw/archives/manuals/dlt_carbtuning.php _________________ 1960 Ragtop w/Semaphores "Inga" |
|
Back to top |
|
|
scottyrocks Samba Member
Joined: August 19, 2016 Posts: 2664 Location: Long Island, NY
|
Posted: Sun Oct 21, 2018 4:26 pm Post subject: Re: Intermittent cut out after acceleration |
|
|
Got it. Page 9, paragraph 11/23. _________________ “If you care for a thing long enough, it takes on a life of its own, doesn't it? Mending old things, preserving them, looking after them – on some level there's no rational grounds for it.”
– D. Tartt, 'The Goldfinch' |
|
Back to top |
|
|
smitty24 Samba Member
Joined: April 28, 2008 Posts: 2723 Location: Salem, Oregon
|
Posted: Sun Oct 21, 2018 5:07 pm Post subject: Re: Intermittent cut out after acceleration |
|
|
Like I mentioned earlier, first thing to do is clean that carb and jets and blow out with compressed air. Most the time your type of symptoms happen when all else is right is crap in your jets or carb, especially with stock single carbs.
I’ve had many stock carb engines do this over the years and it is usually plugged idle jets and small bits of crap getting past filters. Idle jets have TINY drillings. The stock filters are not very good in my opinion. Also, my IDFs did this far more often because stuff got past air filters. When we had forest fires, the ash would get stuck to my filters then implode itself into even smaller particles. It then turned to a sticky emulsion and goes right to your idles! You then start popping and missing on that cylinder. I bought a 30/31 off the internet for my 40horse a few weeks back and it kept cutting out at stops and slowing down. I had perfect tune until it got on the road. I discovered that the manufacturer installed EVERY jet and screw with some type of liquid Teflon seal...which was disintegrating and also going straight to the idle jet. I wire wheeled the crap then the engine ran perfect!
You have to make sure carb and fuel system is clean clean clean. Vw owners don’t seem to understand this enough. Carb and jets must be clean at all times or you have these type of issues. I would also make sure your choke is setup and unloading correctly. I’ve had bypass valves jack up and stick at weird times as well. All stuff everyone should check. Just the nature of owning a classic vw. |
|
Back to top |
|
|
|