[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

[T3] fuel injection poser

I've been working on a nagging problem with my '69 fastback relating to cold
starts and running rich in general. It has been carbon fouling plugs and
gets about 12 mpg. On cold start, engine lopes as if missing on one hole.
THEN idle "hunts" between 1000 - 2000 rpm, THEN calms to the higher idle
once fully warmed.

To further compound my situation, I've learned that my 69 engine was
replaced with a 70 engine that used a fresh air temp sensor instead of
crankcase (oil) temperature sensor. The net effect is that I've got a wiring
pigtail dangling where there should be a crankcase sensor (at the aux. air
switch atop the crankcase).

The following info that Dave Johnson offered has raised some questions:

"The thermo switch does nothing until the engine temp reaches "a high
activating temperature (+50 degrees F and 32 degrees F)"

My 69 had a crankcase temp sensor and a clyinder head temp sensor.  Correct
me if I'm wrong, both act to enrich fuel at cold start-ups, then leans the
mixture as the engine warms to full operating temp.

"The cold starting valve allows fuel enrichment - The valve only operates
when the starter is operated with the temperature below that which the
thermo switch operates".

 " To avoid an over rich fuel/air mixture when starting a cold engine at
temperature between + 50 F and + 23 F, it is important to hold the throttle
valve fully open until the engine fires".

My '69 has no cold start valve.  It starts very well without touching the
throttle at all, but idles roughly until full warm-up. If I open the
throttle it tends to flood easily. Has my footless starting been wrong all
along? Should SOP be to put my foot into it?


pete schutza

List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]