Date:         Sat, 8 Nov 2014 10:41:48 -0500
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: Black Vapor and Rattle. And other stuff.
Content-Type: text/plain; charset="us-ascii"

It is normal for the fuel system to hold pressure. It is desirable and a
goal. Gasoline wants to evaporate quickly and the and fuel systems job is to
prevent the vapors from escaping into the atmosphere. It also has the side
benefit of keeping the gas fresh longer. The stuff that is evaporating is
really the stuff you burns to make your engine go. There is a vacuum
operated valve that opens when the throttle opens to vent the tank into the
air intake to burn off those fumes. Air intake to make up for the fuel being
consumed enters through the carbon canister. These canisters can fail and
clog the inlet hose if you still have the original design. Check the valve
and canister operation.



For your loss of power a common fault is the O2 sensor system not working
properly and causing the engine to go very rich. Rich to the point of black
smoke and all. If you drove any distance this way you filled the exhaust
with soot and may have finished off the O2 sensor and catalytic converter.
An easy test for this next time is to cycle the ignition switch. If it
clears for a short while and comes back the O2 sensor system is the most
likely problem.



For rattle or likely clicking noise coming from one side that just may be a
lifter that bleed down and is not filling as it should. Run it till it warms
up and drive. Sometimes it takes some revving to 4K or more to get a
stubborn one going.



For the high and erratic idle start with temps 2 sensor and the basic
settings such as timing and idle. More likely you have a bad idle speed
controller or possibly the valve. This is common way for the controllers to
fail.



Dennis





> Hi all,

>

> My background; I drive an 87 Syncro tintop with 2,000 miles on a
> rebuilt
2.1 WBX. Fuel tank resealed and new fuel lines run. Coolant lines replaced
as well. A few hundred miles after rebuild I developed a chronic excessive
vapor pressure problem in the gas tank (vent lines most likely pinched on
top of the tank) that was "solved" by drilling a 1/16" hole in the gas cap.
Recently upon start up the van would idle at 1,800-2,000rpm for about 2
minutes but then quiet down. Another existing problem is that the power
steering pump's high pressure banjo fitting leaks due to a crack. I also
have an unreliable fuel sender and ran out of gas about three weeks ago. I
may have noticed a noisier fuel pump since then.

>

> Last night on my way home from a quick trip to Home Depot (about one
> mile)
my van struggled to keep from stalling as if it lost vacuum or compression.

>

> This morning it started right up, but it revved up to ~2,200 rpm.
> Heard a
rattle from the right head area (didn't put a stethoscope or stick on it).
Noticed the usual water vapor that drips out the tail pipe was BLACK. I shut
it down. The coolant looks ok and the oil on the dipstick looks ok.

>

> Got any ideas on what to look at this weekend? I'll probably be
> getting
towed someplace next week, my mechanical skills and tools are basic. Any
recommendations for a shop near Rutland VT? I already checked roadhaus.

>

> Thanks in advance,

> Steve

>

> Sent from my iPhone