still battling hard start/cold start - more info

Konstantin Bogach konstantin.bogach at
Wed Aug 14 11:43:22 EDT 2002

My 200tq had similar symptoms and it turned out to be a engine speed sensor on bell
housing. There are actually two sensors in in one body and I don't remember which one
was bad (or never new that).  Contact where wire goes into the sensor was the
problem.  While cranking engine shakes and change the contact.  When engine starts it
can run without the signal from that sensor.  Contraction while cooling might be also
a factor.  It was deteriorating quickly with time and later I had to open the hood
and move wires to start engine.  Then it came to a point when nothing could help and
I when I changed the sensor (used $50) symptoms were gone.

Good luck.


> From: "Keith Lawyer" <LawyerKG at>
> BRIEF REVIEW: my hard start/cold start problem is: after sitting for 4-5
> hours or more, my '90 200tq is difficult to start regardless of outside
> temp.  I must crank, stop, crank, stop, crank, etc... start!!!  I will
> say that sometimes it idles very poorly for the first 10 seconds or so
> once running.
> NEW INFO:  I discovered that if I allow more time - approx 30 seconds -
> after the first time cranking it fires right up on the 2nd try.  If I
> wait only 3-5 seconds between attempts I must try several times, each
> time with increased success until it finally starts.  What could be
> happening during this 30 seconds after the first cranking attempt????
> Once running I can kill it and restart easily until it sits for 4-5
> hours again.
> MORE NEW INFO:  I discovered I can reproduce the problem by pulling the
> connector on the ISV and allowing the car to chug and die as a result.
> If I then replace the connector, turn the ignition entirely off so as to
> "reset" power to the ISV, and try to re-start I'm back to crank, pause,
> crank, pause, crank, start.
> WHAT'S NEW:  ISV temp sensor, coolant temp sensor.  Swapped in
> different ISV from parts car, cleaned both ISV's w/carb cleaner.
> ALSO: tried jumpering the fuel pump for up to 45 seconds in the morning
> thinking I was losing fuel pressure.  I can hear the pump run and hear
> things gurgle/flow up at the motor, but this makes ZERO difference in
> the behavior of the hard start problem.
> Any help is appreciated, I'm at a loss.  I can't seem to find any
> problem exactly like this in the archives.  The car happily holds 1.4
> and does not overboost so I'm ass-uming no vac leaks.
> Keith L
> '90 200tqa
> -

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