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AB westy nut
Samba Member
Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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 Posted: Mon Jun 15, 2015 1:45 pm Post subject: Stalling when coming to a stop at normal operating Temp. |
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Hey guys and girls, the bus is in a good state of tune but it recently began to stall when coming to a stop. This only occurs after longer highway runs though. It doesn't happen on a 15-20 minute drive around town. I've read a few related threads and most of them speak of either a vacuum leak or valves out of adjustment. But the valves have been properly adjusted and I've tested for vac leaks and found none. I've also noticed that if I'm out driving around town and I stop for 5-10 minutes, when I start it up again the idle is quite high. Otherwise, it idles fine.
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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SGKent 
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Joined: October 30, 2007
Posts: 42983
Location: at the beach in Northern Wokistan
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| Posted: Mon Jun 15, 2015 1:49 pm Post subject: |
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lean the idle mixture a tiny bit
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 Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).
George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."
Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"
1971 deluxe (sold)
1977 deluxe |
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AB westy nut
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Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Mon Jun 15, 2015 1:55 pm Post subject: |
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By way of the idle adjustment screw or the AFM?
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 42983
Location: at the beach in Northern Wokistan
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| Posted: Mon Jun 15, 2015 2:06 pm Post subject: |
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| AB westy nut wrote: |
| By way of the idle adjustment screw or the AFM? |
afm screw. Just a tiny amount, see if that helps. Sometimes when the mixture is too rich the engine will die falling from higher RPM. If you have a fuel to air gauge it is best to set it to the specific factory recommendation on the orange sticker on the engine door.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).
George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."
Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"
1971 deluxe (sold)
1977 deluxe |
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AB westy nut
Samba Member
Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Mon Jun 15, 2015 2:30 pm Post subject: |
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Ok, just to be clear, you're talking about making a small adjustment to the mixture screw on the AFM and not a static or dynamic adjustment to the AFM wiper arm, correct?
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 42983
Location: at the beach in Northern Wokistan
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| Posted: Mon Jun 15, 2015 3:02 pm Post subject: |
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| AB westy nut wrote: |
| Ok, just to be clear, you're talking about making a small adjustment to the mixture screw on the AFM and not a static or dynamic adjustment to the AFM wiper arm, correct? |
correct. Sometimes when the idle is a little rich the engine will die. You need only turn the screw on the top of the afm maybe 1/8 turn leaner and see if that helps. That is the screw that is on the outside. You do not need to go inside the top cover.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).
George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."
Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"
1971 deluxe (sold)
1977 deluxe |
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AB westy nut
Samba Member
Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Mon Jun 15, 2015 3:11 pm Post subject: |
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Ok thanks. I'll give that a shot tonight.
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 42983
Location: at the beach in Northern Wokistan
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| Posted: Mon Jun 15, 2015 3:25 pm Post subject: |
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| AB westy nut wrote: |
| Ok thanks. I'll give that a shot tonight. |
just a little. Drive it until it does it again before changing it. Keep track of which direction you change it and how much. All you need do is get it inside the window where it does not die. If you go further it may get a flat spot off idle.
If that doesn't get it, try another TS-II as they make the mixture rich when they go bad, and they are temperature sensitive. We've had a couple people here who found the issue was theirs had come a little loose. Usually that shows up as worse fuel consumption too.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).
George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."
Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"
1971 deluxe (sold)
1977 deluxe |
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AB westy nut
Samba Member
Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Fri Jul 24, 2015 6:17 pm Post subject: |
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So I've been playing with the idle mixture screw and no amount of adjustment has made any difference to the poor idle and stalling when hot. Timing and dwell are good. Swapped the TSII with another with zero effect. Checked for vacuum leaks and found none. It's a very consistent and predictable problem. Starts and drives great but after about 15-20 minutes it goes suddenly from idling perfectly to not idling and stalling. Thoughts on where to go from here?
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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14platoon
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Joined: October 13, 2013
Posts: 444
Location: United Kingdom
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| Posted: Sat Jul 25, 2015 1:57 am Post subject: |
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| What engine send carb set up have you got? |
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secretsubmariner
Champagne Wrangler
Joined: January 08, 2011
Posts: 3111
Location: Tulsa, OK
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14platoon
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Joined: October 13, 2013
Posts: 444
Location: United Kingdom
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| Posted: Sat Jul 25, 2015 7:15 am Post subject: |
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| Is it cold where you are? Have this issue on my beetle, carb icing. Mine does it when cold, then when it's warm it's fine. An old car of mine used to have your symptoms and basically it was the same thing, carb icing. Obviously if it's roasting hot where you are then forget this post. |
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AB westy nut
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Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Sat Jul 25, 2015 7:28 am Post subject: |
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| 14platoon wrote: |
| Is it cold where you are? Have this issue on my beetle, carb icing. Mine does it when cold, then when it's warm it's fine. An old car of mine used to have your symptoms and basically it was the same thing, carb icing. Obviously if it's roasting hot where you are then forget this post. |
Lol sorry, it's mid July here. 
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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white74westy
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Joined: May 02, 2011
Posts: 779
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| Posted: Sat Jul 25, 2015 7:55 am Post subject: |
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| Are you 100% on your fuel supply? Crud in the filter, water in the fuel, correct pressure, etc? |
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Tcash
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Joined: July 20, 2011
Posts: 12843
Location: San Jose, California, USA
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| Posted: Sat Jul 25, 2015 10:34 am Post subject: |
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If it happens when you apply the brakes. The brake booster is bad. Disconnect the hose and cap the fitting and retest.
Smoke tester
Good luck
Tcash |
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AB westy nut
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Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Sat Jul 25, 2015 1:24 pm Post subject: |
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Well guys, I seem to have found and fixed the problem. All four exhaust valves were really tight. Barely any lash. So I adjusted them back to .006 and the seems to be quite happy again. Holds a nice steady idle when hot. Intake valves were perfect by the way. Valves were last adjusted not even 2000 miles ago.
So this begs the question, why have I had to adjust the valves 4 times in the 5000 or so miles since the rebuild? Adrian at Headflow did my heads. Is it normal after a rebuild for the valves to take some time to find their sweet spot in the seats?
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 42983
Location: at the beach in Northern Wokistan
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| Posted: Sat Jul 25, 2015 1:54 pm Post subject: |
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| AB westy nut wrote: |
Well guys, I seem to have found and fixed the problem. All four exhaust valves were really tight. Barely any lash. So I adjusted them back to .006 and the seems to be quite happy again. Holds a nice steady idle when hot. Intake valves were perfect by the way. Valves were last adjusted not even 2000 miles ago.
So this begs the question, why have I had to adjust the valves 4 times in the 5000 or so miles since the rebuild? Adrian at Headflow did my heads. Is it normal after a rebuild for the valves to take some time to find their sweet spot in the seats? |
No it is not normal. If you are driving at 65 - 70 MPH in really hot weather then you need to slow down, especially if you are heavily loaded and have not tuned the AFM to run the engine cool. If you are driving at acceptable speeds in a VW BUS then time to call Adrian and discuss it. Sounds like the seats are sinking or being pounded into. Valves could be stretching too which can be a disaster if one snaps. From what others have told me from their first hand experience, there have been some serious QC problems with that shop lately. It is still heresy as I have not used it. You will need to speak with them about the issue as likely the heads will need to be inspected. .006 x 2 = .012 migration in 5000 miles is a lot.
Below is a screeshot of the spread sheet on some heads RIMCO did for me back in 2008 before Ed sold the business. Click on it twice to expand it. Were I to do it again today because of the changes in the industry I would buy new upgraded AMC heads from either Len at HAM in GA, or Donny at DK Mach and Fab in SoCal.
_________________
Canned Water - the new California approved parts cleaner (except in a drought in which case rub it with sand).
George Carlin:
"Most people don't know what they're doing, and a lot of them are really good at it."
Skills@EuroCarsPlus:
"never time to do it right but always time to do it twice"
1971 deluxe (sold)
1977 deluxe |
|
| Back to top |
|
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AB westy nut
Samba Member
Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Sat Jul 25, 2015 2:14 pm Post subject: |
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Well I do a lot of weekend camping which includes about an hour of highway driving. Temps anywhere from 20c to 30c. Speed usually about 60mph and never over 65. Me and two small kids and some light camping gear. AFM is dialed into to where it should be as per Colin's write up. Runs and drives great all day long. I'll check the valves again in about 1500 miles and if they've tightened again I'll give Adrian a shout.
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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AB westy nut
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Joined: June 01, 2010
Posts: 1125
Location: Calgary, Alberta
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| Posted: Sat Jul 25, 2015 10:33 pm Post subject: |
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I just looked back through my notes and it turns out I haven't adjusted the valves as often as I thought. Here are some details:
Engine rebuild at 82,700 miles
First valve adjustment 500 miles later at 83,200. All I noted was that all valves were slightly tight.
Second valve adjustment at 83,800. Intakes were fine. 1 & 2 exhaust were a 'tight' .006. Exhaust valve #3 was .005 and #4 was .003.
Latest valve adjustment at 86,300.
So 4 tight exhaust valves in 2500 miles. 
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1963 Ruby Red 356 Cabriolet
1976 Sage Green Westfalia Deluxe |
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WhirledTraveller
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Joined: January 09, 2008
Posts: 1414
Location: Cambridge, MA
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| Posted: Sun Jul 26, 2015 6:12 am Post subject: |
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If you are not running a cylinder heat temperature gauge, I would add one. Tight exhaust valves are usually a symptom of overheating. If it continues to sink you are going to need a new set of heads at the least and possibly a whole new engine if an exhaust valve breaks.
I have the upgraded AMC from HAM which are pricey but I don't really have valve adjustments any more just valve checks. They haven't tightened up more than .002 over 20,000 miles.
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