Slight starting issue

We're talking the Wonderbus here.

New Mexi 1600 longblock w/ SVDA dizzie, new 34 PICT/3 carb w/ choke
connected. Stock oil bath air cleaner with air pre-heat hose connected,
clean manifold with preheat tubes clean and connected.

Cold starts -- very easy.
Hot starts (dash into 7-Eleven for curry Squishie) -- also very easy.
Warm starts (sittin' for 30 minutes) gotta run the starter motor for 4-5
seconds before engine catches.

Maybe the choke does not quite track the engine's condition in between
hot and cold?

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR

Mike Rocket J. Squirrel Elliott wrote:
> We're talking the Wonderbus here.
>
> New Mexi 1600 longblock w/ SVDA dizzie, new 34 PICT/3 carb w/ choke
> connected. Stock oil bath air cleaner with air pre-heat hose
> connected, clean manifold with preheat tubes clean and connected.
>
> Cold starts -- very easy.
> Hot starts (dash into 7-Eleven for curry Squishie) -- also very easy.
> Warm starts (sittin' for 30 minutes) gotta run the starter motor for
> 4-5 seconds before engine catches.
>
> Maybe the choke does not quite track the engine's condition in between
> hot and cold?

Check valve clearances.

J.

P.J.Berg wrote:
> Mike Rocket J. Squirrel Elliott wrote:
>
>>We're talking the Wonderbus here.
>>
>>New Mexi 1600 longblock w/ SVDA dizzie, new 34 PICT/3 carb w/ choke
>>connected. Stock oil bath air cleaner with air pre-heat hose
>> connected, clean manifold with preheat tubes clean and connected.
>>
>>Cold starts -- very easy.
>>Hot starts (dash into 7-Eleven for curry Squishie) -- also very easy.
>>Warm starts (sittin' for 30 minutes) gotta run the starter motor for
>>4-5 seconds before engine catches.
>>
>>Maybe the choke does not quite track the engine's condition in between
>>hot and cold?
>
>
> Check valve clearances.

..006''

--
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR

"Mike Rocket J. Squirrel Elliott"
et> wrote in message
news
>
> Maybe the choke does not quite track the engine's condition in between
> hot and cold?
>
>

................That's right. It doesn't work effectively when the ignition
has been off for more than a few minutes. You get too much choke with a hot
engine and flood the engine. I used to adjust it back almost all the way
'lean' when driving in hot weather to lessen this problem. Another thing
that could be working against you is the common problem of engine heat
causing the gas to boil out of the carb's float chamber and causing flooding
as well. I don't know of an easy fix for that one. Do you have one of those
fiber whatever isolators between the carb and the manifold?

Tim Rogers wrote:
> "Mike Rocket J. Squirrel Elliott"
> et> wrote in message
> news >
>>Maybe the choke does not quite track the engine's condition in between
>>hot and cold?
>>
>>
>
>
> ...............That's right. It doesn't work effectively when the ignition
> has been off for more than a few minutes. You get too much choke with a hot
> engine and flood the engine. I used to adjust it back almost all the way
> 'lean' when driving in hot weather to lessen this problem. Another thing
> that could be working against you is the common problem of engine heat
> causing the gas to boil out of the carb's float chamber and causing flooding
> as well. I don't know of an easy fix for that one. Do you have one of those
> fiber whatever isolators between the carb and the manifold?

There's a composite gasket about 1/16'' between the carb and manifold,
but I'm not sure how this boiling gas theory works. The engine starts
fine when it's at operating temperature -- like only been off for a few
minutes. And it starts fine when it is cold. It's the in-betweenly
condition that it grumbles about, like having cooled down for 30 minutes
or so from normal operating temp. Does that jibe with the
boiling/flooding scenario?

Mind, it's not a problem, the engine starts after a few seconds; it's
just something that I've been noticing and have been mentally worrying,
like a dog a bone.

Heh. I said "bone."

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westphalia: "Mellow Yellow (The Electrical Banana)"
KG6RCR

There's a thin person inside every fat person - I ate mine...
-- Graffiti

"Mike Rocket J. Squirrel Elliott"
et> wrote in message
...
>
> There's a composite gasket about 1/16'' between the carb and manifold,
> but I'm not sure how this boiling gas theory works. The engine starts
> fine when it's at operating temperature -- like only been off for a few
> minutes. And it starts fine when it is cold. It's the in-betweenly
> condition that it grumbles about, like having cooled down for 30 minutes
> or so from normal operating temp. Does that jibe with the
> boiling/flooding scenario?
>
>

..............1/16" sounds too thin, try 2 or 3 instead. It takes a while for
the heat to conduct into the carb float and boil out the gas through the
vent tube. 30 minutes is probably what it takes to flood out the
cylinders......I'm just guessing. I have a digital thermometer probe in the
engine compartment of my '77 bug because I was worried last year that my tin
wasn't properly isolating the the topside of the tin from the heated air
exiting out the bottom. One thing that I've noticed is that the engine
compartment is never much more than maybe 10 deg. higher than the outside
ambient temp while I'm driving but when I turn the engine off, the
compartment starts heating up to well over the 160 deg. limit of the temp
probe/gauge within a minute or two. I don't remember what the boiling point
of gasoline is but it's not very high. So it could be more than just heat
conducting from the manifold into the carb that causes this. Of course,
since I'm running an L-Jetronic EFI system, I don't ever have these problems
anymore........BWAAAHAHA !!!!

Why don't you open the engine compartment lid the next time you park it for
30 minutes and see whether that makes any difference in how it starts?

Another idea: Since you're in a warm climate, put a block off plate in the
joint where the manifold heat tube is attached to the muffler. Drive around
and see whether it starts better and whether you even need manifold heat in
Sandyeggo. I wouldn't try it up here in damp and cold NY but maybe it would
be OK for you.

Is this something that a CDI would help?

John
'71 Campmobile

On Fri, 29 Oct 2004 02:26:43 GMT, jb > wrote:

> Is this something that a CDI would help?
>
> John
> '71 Campmobile

No.

Max
--
http:/www.MaxWelton.net/

"Tim Rogers" > wrote in message
> Another thing
> that could be working against you is the common problem of engine heat
> causing the gas to boil out of the carb's float chamber and causing flooding
> as well. I don't know of an easy fix for that one.
-----------------------------------------------------------

Me neither. The problem is that the manifold is HOT... if the engine
has been properly assembled (ie, cross-over pipe is not clogged).
During warm weather the siamesed portion of the intake manifold -- the
part having the aluminum jacket -- contains a significant quanta of
heat that gets dissipated into the engine compartment when you shut
down the engine. A lot of that heat gets absorbed by the carburetor
even WITH a gasket that provides good thermal isolation between the
carb and the manifold... the carb has a lot of surface area and the
air around it is HOT and things roll downhill from there.

I've used two techniques that help the situation. The first is to
ALWAYS idle the engine for at least a minute before shutting down.
I've got a clock right in front of me (where I usta have a sun visor)
and you wouldn't belive how long a minute can be, just sitting there
watching the gauges. How much does it help? Frankly, not a bunch...
depends on the weather. Seriously hot day, it helps. Cold day, you
won't see any change. Middling-warm, like we usually have here in
sudden California... sorta iffy. But I've made it a habit, don't
really notice it any more.

The second technique was hi-tek kewl. 12vdc computer fan that comes
ON when the ignition goes OFF via a thermostatically controlled relay.
When the temp at the sensor drops below 140, the thing shuts itself
off. So you get to where you're going, climb out, walk away, the fan
keeps humming away back there, eventually shuts itself off (you hope).
Nothing very tricky about the set-up; ripped the parts out of a Ford
'Tempo' (? - I lose track) Radiator fan temp sensor. All I did was
add a couple of relays to include a fail-safe.

So howz that work with the hard-starting? ONE fan, blowing on the
carb, I didn't see any change. TWO fans, both blowing air OUT of the
engine compartment, I saw a definte improvement.

But a couple of additional points need to be mentioned. The first is
that damn PICT-34. It appears to be a LOT more sensitive to engine
compartment heat than the older round-bowl carbs. Since I stopped
using 34's I haven't had any problem with hot starts. Keep in mind, I
drove a '65 whereas Rocky flies a 'loaf. My engine compartment is
vented directly out the sides of the van whereas he's got that l-o-n-g
upward column to those high-placed vents up behind his rear windows.
I suspect his engine compartment stays hotter, longer, than mine does
and is a contributing factor.

Bottom line: You really gotta love fuel injection :-)

-Bob Hoover