Re: skeptical about ECU diagnostic!

[Kneale Brownson <knotnook@traverse.com>]

At 08:42 PM 9/26/99 -0500, Livolsi, Stephane wrote:
>I posted a while ago about hot starting and poor idle situation with my
>86 5KTQ.  Also, I max out at 1.2 bar of boost, which apparently is not
>enough.  Got lots of suggestions and am running them down, thanks
>everyone for your advice.  I haven't checked the injectors or fuel pump
>yet because I ordered new ones and they aren't here yet. (I'm worried
>about not being able to put an old one back in so I want to make sure
>the new ones are here first)
>
>Anyway, I went for a drive and really exercised her.  I actually got a
>1.3 bar on the turbo gauge.  After this drive I put it into diagnostic
>mode (fuse in the fuel pump relay) and I got the 4444 (no faults).  This
>actually disappointed me because I was hoping to find an answer to my
>hot starting and poor idle problems.   HOWEVER, on closer examination I
>notice that the valve cover breather hose was SPLIT WIDE OPEN creating a
>huge vacuum leak.  I replaced the broken section of hose and with great
>excitement and expectation  fired her up.....  Alas, it actually runs
>worse than before!!  If I let off the gas the engine dies.  Oh, well,
>next item on the list....
>
>Regards
>
>
>Stephane Livolsi
I had the same experience, Stephane:  Replaced rotten hoses on my '87
5KCSTQ in the line between the  crankcase breather and the valve cover and
intake elbow, only to have the car run worse.  (But I'd not had any
starting/idle problems before).   Looking at Scott Mockery's wonderful
diagnostics pages, I started poking around the Michelin Man hose, and
discovered a split in the bottom side of it (where the oils settle on the
inside).  Bingo, I thought, but that was just the beginning.  Then I
discovered the idle/WOT switch is the OEM equipment Scott discusses, so I
replaced that with the "new" style someone'd already put on my parts car,
and, after some fiddling it ran more like before I started "fixing"
anything.  I can get 1.3 bar regularly now, but the 1.4 that's supposed to
occur when all's OK remains elusive.  I saw that with one of my adjustments
of the WOT switch, but I also had a 1100-1200 RPM idle with that setting,
so when I readjusted to get the normal idle, I lost the 1.4.  I probably
should buy a new WOT switch.

Kneale Brownson