One step forward, One step back

[Audial@aol.com]

Update to the ongoing saga of my auxiliary coolant pump:

Thanks to list members who suggested a genuine 12v supply test.  The pump
works, hums and gurgles.  The switch that controls it also works.  So, to
summarize:  Injector Cooling Fan:  bad switch -- $25 @ dealer.  Aux. Coolant
Pump:  Suspect bad relay, haven't dug enough to find it yet.  Cost still up
in the air, maybe I can fix the relay (?).

Now, for the real chagrin.  I was getting worked up to install the "trick S6
cooling fan" that I so lasciviously described in a previous post.  It turns
out that you must remove the fan shroud from the radiator in order to get the
fan & motor out to do this.  First you must loosen the radiator expansion
tank, three phillips screws. Ok, you say, then it's just five bolts.  The top
three go pretty easy, but the bottom two are rusty.  The lh bottom bolt is
both rusty and inaccessible, due to its proximity to A/C lines.  After some
penetrating oil and whacks with a punch and some prayers and a brake-line
wrench, it comes loose.  Fan shroud and motor are removed.

Get the bolt off the front of the fan motor (reverse-threaded), tap the fan
off the shaft with a rubber mallet.  Of course, the fan that I bought is the
wrong one.  The motor shaft is much larger than the available orifice.  Plus
the overall fan diameter is about 1" smaller than the original, 4-blade fan.
 Back to the dealer.  Does anyone have the correct PN on this replacement so
that it will fit my fan motor?  

OTOH, some good things came of this.  The fan shroud itself was cracked from
the torque of the fan working on it, which I will fix with some good epoxy.
 I replaced a bad grommet holding the radiator.  I also got a chance to clean
the radiator and A/C.  Finally and most importantly, I noticed a trickle of
coolant that was coming from the expansion-tank union to the radiator.  One
loose hose clamp was the culprit.  Eventually it would have blown off and
been a big pain to put back on with the fan shroud in place.  

BTW,  doing the "bomb" does not look like fun.  The big banjo is very rusty.

While I was at it, I decided to try and answer my own question and take a
look at the innards of the MAC-11b ECU.  The pressure sensor looks like it
"might' be replacable if it is in fact the culprit, but I'll have to x-acto
it from the PCB it's mounted to and then resolder the four wires that connect
it.  Now, though, I'm thinking that's not the problem.  I'm going to really
check out the vacuum lines again.

One unequivocally nice thing that happened is that the Blue Igniters from
Rapid Parts came, loom included, and the total job installing them took 10
minutes.  They look great and seem to have cured the engine's slight idle
stumble. $100 w/shipping.

Best Wishes,

Alex Kowalski
'86 5KCSTQ