Idle Control problems

  • Thread starter Thread starter Jim Lee
  • Start date Start date
J

Jim Lee

Hi,
I am pretty new to Volvos and my 1988 240GL is puzzling me because I
have read that there should be power going to it as soon as you turn
the key to position 2. Before starting, with the ignition/accesories
on it should have power in one of the three wires that go to it. I see
a green wire with a red stripe that I would assume (until my Bentleys
manual arrives in the mail tomorrow hopefully) is hot. A brown wire
which I think comes from the temperature and a white wire. I do not
see any power going to any of those three wires which makes me think
that the ICV has been either all the way closed or all the way open
and accounts for my inability to keep the car from stalling when first
started. I have to sit there for a few minutes ready to tap the
accelerator to keep it from stalling out 2 or 3 times. After it gets a
little bit warm it drives fine. I have removed the ICV and it looked
fine. The 90 degree vane is free and clear and not all gummed up. I am
getting another one this week but I am beginning to wonder if it is
going to do me any good if I don't get any power at that connector.

Could someone help me with scenarios where that switch would not be
gettin any power with the ignition on? Could it be my throttle switch
is not set correctly or working?
Would that prevent power from getting to the ICV? The temperature wire
not working?
My worse case scenario imagines a problem with the ECU which would
really surprise me as the car has 'only' 110k and has been very well
taken care of in general.
And if in fact this ICV has not been working the car runs very well
after the first few minutes of keeping it from stalling. It runs very
well in fact. The usual new stuff when you get an older car has been
replaced by me. Plugs, rotor, cap..all fluids changed. Outside of this
I am very happy with car.

I guess my main question is first if I am correct in thinking that the
ICV should have power as soon as you turn on the ignition as I may
have misinterpreted this or skipped over something. And if there are
any 'normal' circumstances, not for example the ECU not doing its job,
where there would not be enough power getting to that valve to light
my testor light.

Thanks very much,
Jim Lee

1988 240GL
 
Jim said:
Hi,
I am pretty new to Volvos and my 1988 240GL is puzzling me because I
have read that there should be power going to it as soon as you turn
the key to position 2. Before starting, with the ignition/accesories
on it should have power in one of the three wires that go to it. I see
a green wire with a red stripe that I would assume (until my Bentleys
manual arrives in the mail tomorrow hopefully) is hot. A brown wire
which I think comes from the temperature and a white wire. I do not
see any power going to any of those three wires which makes me think
that the ICV has been either all the way closed or all the way open
and accounts for my inability to keep the car from stalling when first
started. I have to sit there for a few minutes ready to tap the
accelerator to keep it from stalling out 2 or 3 times. After it gets a
little bit warm it drives fine. I have removed the ICV and it looked
fine. The 90 degree vane is free and clear and not all gummed up. I am
getting another one this week but I am beginning to wonder if it is
going to do me any good if I don't get any power at that connector.

Could someone help me with scenarios where that switch would not be
gettin any power with the ignition on? Could it be my throttle switch
is not set correctly or working?
Would that prevent power from getting to the ICV? The temperature wire
not working?
My worse case scenario imagines a problem with the ECU which would
really surprise me as the car has 'only' 110k and has been very well
taken care of in general.
And if in fact this ICV has not been working the car runs very well
after the first few minutes of keeping it from stalling. It runs very
well in fact. The usual new stuff when you get an older car has been
replaced by me. Plugs, rotor, cap..all fluids changed. Outside of this
I am very happy with car.

I guess my main question is first if I am correct in thinking that the
ICV should have power as soon as you turn on the ignition as I may
have misinterpreted this or skipped over something. And if there are
any 'normal' circumstances, not for example the ECU not doing its job,
where there would not be enough power getting to that valve to light
my testor light.

Thanks very much,
Jim Lee

1988 240GL

The brown wire that goes to the center terminal gets power from the fuel
pump relay. This wire is connected to the wire that powers the fuel
pumps, so should only have power when the fuel pump is running. The
computer grounds the other wire, one to open the valve, the other to
close it.
I would suggest cleaning the throttle body as a first step in solving
your problem.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
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