[Shotimes] My sick SHO again

[Paul L Fisher]

Just want to make sure, CPS and CID, crank and cam sensor?

What year, what tranny?

Usually low mileage is either bad O2 sensors (normally throws a code) or the
engine isn't warming up. Three are at lest 3 coolant temperature sensors.
The 2 wire one feeds the idiot gauge on the dash, the three wire one in the
same area feeds the PCM, the CELO sensor in the heater core supply pipe
keeps the interior fan off until the engine is hot.

If you haven't replaced the thermostat, I would look into that. Make sure
you get one with a jiggle valve on it.

As for your tach not working, the only other thing you haven't replaced is
the DIS.

Since you didn't include the IAB in your list, the low RPM stumble could be
it. Try cleaning it.

You can clean the MAF with some contact cleaner available at Radio Shack.

Do you throw any codes? Run a KOER and KOEO test and post the results.

My ATX got 20-21 MPG consistently in mixed driving and 25 or so on the
highway.


Paul L Fisher

1999 Ford Taurus SHO TR 64K - Stock. Kirk'ed.

Visit my website: http://www.paul-fisher.com
SHOClub Member: http://www.shoclub.com
Amsoil dealer: http://www.paul-fisher.com/oil


-----Original Message-----
From: shotimes-admin@autox.team.net [mailto:shotimes-admin@autox.team.net]
On Behalf Of Jonas Diener
Sent: Tuesday, April 20, 2004 1:12 PM
To: shotimes@autox.team.net
Subject: [Shotimes] My sick SHO again

Thanks for all your suggestions regarding my last long post.

Unfortunately I still haven't got it all worked out.

The main problem is a stumble at low RPMs, especially when the engine is
still cool.  It also is hard to start sometimes, and feels somewhat weak at
higher RPMs -- Feels as if the spark timing is retarded.

I don't get very good fuel mileage either.  My last tank of 93 octane got me
about 14MPG.

So far I have replaced (in the order listed) the inline fuel filter, CID
sensor, CPS, plugs & wires (sealing the plug wells at the same time), and
the DIS module.

The plugs & wires made a big difference.  It no longer misses or burns fuel
in the cats.  The other things didn't seem to make any difference.

I also checked the fuel pressure at idle and under load.  It looked good.

It seems as if the air/fuel mixture is screwed up.  When it's cold, if I
snap the throttle wide open at idle, it will chug and hiccup for a second or
two before it revs up, sometimes even stalling.  It's not as bad when it
warms up, but it's not right either.

The guy I bought it from seemed to think the MAF sensor had a problem,
although he didn't elaborate as to why he thought that.  Visually it looks
OK and I've re-seated the connector a couple times.

The tach on the dash has never worked since the day I bought it, which is
what led me to suspect a DIS problem.

Another weirdness is that the temp gauge always reads low.  It does move, so
it's not totally broken, but it never makes it above the bottom white line
on the "normal" range.

I replaced both the thermostat and the sender unit to no effect.

I also dropped the Y-pipe to check for the nasty sand stuff.  While the pipe
is shaped in such a way that I can't see into the cats, I shook and knocked
it around a bit and no sand or other debris fell out.

Anyway, the possibilities for what's causing my stumbling problem are being
narrowed down.  Right now I think it could be any of the following:

* A vacuum leak.  I've have ordered a new upper intake gasket thinking it
may be leaking there.

* The butterflies for the secondary intake runners are stuck open.  I plan
to clean the intake good the next time I have it off and check the butterfly
operation with a vacuum pump.

* The MAF sensor is indeed screwed up.  (or the BAP sensor.)

I'm half tempted to buy an LPM as a remedy.

The computer doesn't report any meaningful codes.  Sometimes KOEO finds an
IAB problem and sometimes it doesn't.  The stored codes have told me the
HEGO sensors read too rich, as well as too lean.   I have yet to have it
complete a KOER test without stalling (tried many times on different days at
different engine temps).

I'm open to ideas...again.
-- 

the truth may be out there
but lies are in your head
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