Camper Special - won't idle when cold (video)

[Randy in Maine]

http://www.itinerant-air-cooled.com/viewtopic.php?f=50&t=7834

The CS camshaft doesn't produce a lot of vacuum at idle speeds either. Just the way it is. I have my idle set to about 950 RPMs and it seems to like that speed.

[airschooled]

There is an AAR adjustment page over on Itinerant Air Cooled. Sorry I can't post the link from my phone. If this doesn't help you out, put the AAR in the fridge for an hour before attempting the adjustment. That should help open it up a bit.

AAR adjustment is one of things where there isn't really a ton of info on published specs, so we adjust to suit our needs. It also doesn't affect engine performance or tuning once the engine is warmed up, so it's a relatively harmless adjustment.

Robbie
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[otiswesty]

My camper special has a low idle cold that stalls occasionally. If I am off and going onto the freeway, no problem. But in town at stoplights I have to hand brake and feather the throttle when cold. Neither safe not pleasant and over the years, I have had to do this plenty. So I know the drill.

The engine idles perfect at warm operating temps. I pulled the AAR and replaced with another spare that I had with a larger aperture by visual comparison. I have the bus in the shop to get scoped and everything looks spot on, but they can't get the cold idle problem figured out either. I have a spare 914 CHT I just got and plan to install that. I'll test out my 2 extra AARs and see if they are functional.

Any other suggestions for a bus lover, not a hater, would be appreciated. It seems like a common issue only at cold idle, so some sort of modified AAR or FI adjustment should be able to solve this.
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1978 Sage Green P22 Westfalia
1988 T3 Syncro Single cab

Just a regular guy

[notchboy]

[otiswesty]

[notchboy]

Stew took it out and we did all the prescribed stuff. It's broke and needs to be replaced. I'll make a trip to ooo orerieys .
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[airschooled]

[notchboy]

My AAR is confirmed dead. Getting one now. When looking for one I found several that look the same but are for BMW and Audi. Whats the fundamental difference? A faster or slower open speed?
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[WhirledTraveller]

After years of messing with it, I finally have my CS engine idling "pretty well". Good at idle warm, good at idle cold, a little low spot when lukewarm. Changes in no particular order:

Tuned idle AFR to 15-16 warm
Replaced chromoly pushrods with HD aluminum from aircooled.net, set lash to 0.006
Fixed all vacuum leaks
Set timing to 29 BTC hoses off
adjusted AAR close to maximum
Replaced 20w50 oil with 5w50
Replaced worn out throttle body with the slightly larger throttle body from a 2.1L Vanagon which is in much better shape.
Replace TS2 every two years "whether it needs it or not"
Higher stall speed torque converter from a Vanagon (obviously I have an automatic)
Adjusted throttle linkage and cable precisely according to the Bentley procedure
Cleaned and lubed throttle hinge and spring

Hard to say what was the magic bullet, but I can confirm the engine can be made to idle pretty well although maybe not as well as stock. I think the new throttle body and the aluminum pushrods made the biggest difference.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[Randy in Maine]

I also let it warm up until the CHTs get to around 200º. Then it works like it should.

[notchboy]

I have to say that my CS kit with 300cc increase is a cold blooded biznatch. I have to warm her up - despite the above prescribed checklists.

But I dont mind to much. The pay off is where its at
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[Randy in Maine]

Yes.

[otiswesty]

[KCropsey]

Hey everyone, thank you for your help and your responses. I really appreciate it. My name is Kyle and I am friends with Mike (ObnoxiousBlue) he has really been helping me out with a lot of different things since I am just about 2 months into having a bus. I'm starting to learn things and we have already knocked out some small things. But as of now I am really only having two issues, 1) being that cold start/idle issue, and the other being the cylinder temp while on long(ish) drives. After being on the highway for about 15 minutes doing 55-60 mph my head temp is reading 400 degrees or above and I have to keep slowing down. Mike and I are going to check out the AAR I believe and possibly the sensor that's reading the temp. I know these things aren't meant to be doing 90mph but I didn't expect to be doing 45 on the highway! haha. And a Jake thank you so much for responding. I know this really isn't your problem anymore since I bought it off of someone else, but I'll pm you his name. Thank you again

[obnoxiousblue]

[williamM]

when working on outboards, we used to put red nail polish on all the screw heads- you know to keep them from moving-
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[Jake Raby]

PM me the name of the original owner of the engine. I bet it was a kit, and not a turn key.

Typically the CHT sender is the cause of this, especially if it's new. The AAR is another variable that's real, and possibly vacuum leak.

It's not the CS that causes this, it's the lack of proper tuning, old parts, and most often a worn out throttle position switch that has a dead spot right at idle.

AFM adjustments are also to blame quite often, so are wire harnesses with corroded wires, and poor continuity.

I recently serviced a CS that I built in 2001, since I set it up, it hasn't been touched tuning wise. I didn't touch it either.
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[Clatter]

Reminds me of the old days in Denver...
My friend Marco was SO proud of his Gene Berg parts.
He had a Berg crank and Berg Kadrons on his 1776.
We didn't have three nickels to rub together, and Marco had like six months' wages into his motor.
It wasn't running the way he wanted,
So he called Gene Berg for some advice.
He got thoroughly berated - hearing how "a 14-year-old-girl just tuned her Kadrons all by herself"!
And how his 041 heads were a "bastard head size" and "call me when you read the manual!" And he hung up on Marco just like that..
Marco was SO disillusioned. He worshipped the guy.
From that point forward,
Whenever he got the least bit of trouble working on cars,
(He worked on cars)
We would always heckle;
"Maybe you should call Gene Berg!"

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Bus Motor Build

I have excellent news for the world...
There is no such thing as patina.
It does not exist!

[Clatter]

[notchboy]