Re: My 89 740 GL saga.....
Well, it is fixed!
Could not find an ignition amplifier ANYWHERE on the 92 turbo, so
I decided to forget it and check that crankshaft position sensor out
first. I found that the wires, right where they join the body of the
sensor, had lost their insulation....it had just been dissolved by
some grease that was on it (or maybe some sovlent/grease mixture). It
was just gooey " mush", with 3 bare metal wires within an inch of the
sensor. The wires were shorting, thus killing the signal. I just
cleaned the grease/goo/melted wiring insulation off, and encapsulated
the exposed wires in automovitve "goop" (after detemining that the
stuff is a good insulator), wrapped it all up in fusion wrap, and
reinstalled. On the code readout block, I reset #6 jumper (which had
the two codes set) and then was getting 1-1-1 ...AMM and crank
position sensor codes had cleared. It still didn't want to start, but
I had the timing too far off. Finally got timing close enough, and she
I think I still do not have the timing quite right....power seems
OK, but when you start up from a stop, you hear a clattering sound, I
think it's ping or detonation. Didn't do that before the breakdown.
I can't set timing very accurately as the timing belt cover is gone,
and with it the index. The timing belt cover got torn up by a failed
vibration damper a long time ago. So I noted that on the 92 turbo
740, the engine is at TDC when the mark is at 1 o'clock and set it
there....and on the 89 sedan, the #1 piston does seem to be at TDC
with this position.
Also the car had a very minor miss before this breakdown, and I
just installed a new distributor cap and rotor as they were pretty
worn. Well, it still has the miss...in fact seems a bit worse! All
the plugs are pretty new. Only other thing is the plug wires....could
one of them be causing the miss?
Thanks to all , Jim
On Thu, 27 Oct 2005 08:58:41 -0400, Mike F
>> Ok....I need a little help from someone who is familiar with the '92
>> model 740 Gl. On the broke-down '89 model 740, I did locate an
>> electronic module that has a heatsink and a round 5-wire connector.
>> The Haynes diagram shows a unit with a 5-wire connector identified as
>> an "ignition control module", not a power amplifier. "Power amplifier"
>> is not listed! It is located just behind drivers side dash, close to
>> the the left wall.
>> In looking at the diagram of this module, there are two wires going to
>> the distributor, a brown and green one. WHat are these for? Could they
>> be a crankcase position sensor input? Because the other fault code I
>> am getting (besides for the AMM) is "crankcase position signal bad or
>> missing", or something to that effect. Is there maybe a Hall-effect
>> pickup sensing distributor rotor position? Ha! Maybe the rotor or
>> distributor cap is bad! But if not.....I need to swap in the
>> ignition control module from the 92 Volvo 740 and see if that is the
>> fix. Problem is, I looked in the engine compt. and behind/underneath
>> LH dash, and couldn't spot it. It's in a different place. I do see a
>> similar ECM just to the right of the brake pedal....but no ignition
>> control module. Any clue where they stashed it on the 92 model?
>A few points:
>I've never seen or heard of that ignition module going bad, so you're
>probably barking up the wrong tree there. (Now someone will surely
>write and tell me about how theirs went bad.)
>The ignition amplifier, aka power stage, aka ..., is located on the
>inner fender near the front of the car. Check between the airbox and
>fender. This unit switches the high current low voltage that provides
>the energy to the coil. This is what Peter was talking about, and is a
>Your 89 non turbo won't have a hall sender in the distributor, it's the
>first year of the crankshaft position sensor. This is also a common
>failure part, and is located on the top of the bell housing, just under
>the distributor. And since the car won't run without it and you have a
>code for this...