this seems bad

[Livolsi, Stephane]

I think I broke my 86 5ktq

First the good news, Tihol and I took the quad 4 lamp system from the 84 5kt
parts car and converted the 86 5ktq.  Looks nice and I can see at night.  I
had read people's comments about the difference, but you really have to see
it to appreciate it.

Now the bad news.  I have been fighting an intermittent stumble for quite
some time now and just could not nail it down.  Nothing I did fixed it.  So
this weekend we checked some wires and connectors, checked the spark plugs-
which all looked good (these are the recommended tri electrodes about 1 yr
old), but we could not find anything amiss.  So we went for a good haul,
hitting 1.4 bar and WOT a few times - idle was good, acceleration was good
and just a hint of stumble occasionally -but not at WOT.
The stumble used to be particularly noticeable when starting out from a stop
unless I got the rpm well over 3000.  Perhaps unplugging and replugging some
sensors had cleaned the terminals enough, I don't know but it seemed to run
better.
It seemed to me that the spark plug gaps might have been a little large, but
should you adjust these?

Last night I went for a country drive to 'experience' the new headlights and
did a WOT run. Well, something went.  Right after coming off WOT, and ever
since, the car stumbles like it is running on 4 cyl.  It idles right around
850-900 rpm and steady, but not smooth.  When sitting in neutral, I can
bring it up from idle and it sounds very rough and missing up until about
4000 rpm then smooths right out.
On the road, I have absolutely no power at all in 2nd gear at 2000 rpm.

This stumbling that I have now seems different than my previous problem of
missing once in a while.  The missing was more intense and more of a severe
engine cutout.  This new stumbling is annoying and totally robs power, but I
don't get the hitting an invisible brick wall syndrome.

I know I have lots to check, but I'm just throwing this out in the hopes
that someone has BTDT exactly and can tell me " oh, your so and so isn't
doing this or that and so you do this and all will be ok"

Tonight I will do a compression check, look for oil in the water and water
in the oil and check vacuum.  Speaking of checking vacuum, what is the
general consensus on where to tap into the system to apply the vacuum?

Thanks

Stephane