Ulysses

"Simon H" <simonh@deadmailbox.com> wrote in message
news:dn4f8s$apm$1@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com...
> 4.0 V6 year 2000 Explorer (UK)
> In certain condidtions my Explorer suffers from 'sluggish' accelleration
> which can be quite alarming (and dangerous) when pulling out into traffic
> and nothing much happens when I stomp on the gas...
> From a standing start everything seems fairly normal - in comparison to
the
> '98 Ex I had before this one, anyway.
> The problem arises from a low speed rolling start. A typical scenario is
in
> a line of traffic at a level or slightly downhill junction or
intersection.
> Traffic enters the main road fairly regularly so the line keeps moving at
> approx 5mph. I get to the head of the line still trundling along at less
> than 10mph, see a gap in the traffic and stomp on the gas expecting to
> unleash the 200+ horses hiding under the hood. Not much happens! The revs
go
> up a bit and there is some acceleration and I can hear the motor 'trying'
> and sense a small amount of torque converter slip. The impression at this
> point is like being in a high gear (I suspect it's 3rd). Eventually after
> what seems like an age but is probably 5 or 6 seconds, the truck
'realises'
> that I want it to 'go' and it changes down a gear and starts to accelerate
> and then changes down another gear and really takes off like I wanted it
to
> do in the first place.

Since you don't seem to say what you've checked besides the throttle
position sensor let me ask: did you check the air filter and fuel filter?
Have you checked the mass airflow sensor? What about the spark plug wires?
To me it sounds like a transmission problem but I'd check those things
first. Check the vacuum lines too.

>
> OK, that was problem #1
>
> Problem #2 may well be linked. When maintaining a steady speed (any speed
as
> long as it's constant) between approx 50mph and 80mph I get an
intermittent
> misfire. It's like a momentary cut out, not like a single sparkplug going
> off for a moment. I suspect something like a throttle position sensor
might
> be at fault as the feeling is pretty much like when the throttle position
> sensor went bad on a car I had a few years ago.
>
> Has anybody got any idea where I should start looking? (apart from in the
> rear view mirror when I've just pulled into traffic...) Oh! and don't
> suggest booking it into a Ford dealer! Ford dealers here in the UK know
> absolutely nothing about Explorers :(
>
> TIA
> Simon H
>
>