ford escort problem...

Hi,
i have a ford escort, it's from the year 1999. It's a 1.6 zetec and has been okay up until now. When I brake and put my foot down on the clutch to change
gears, the revs drop right down and the car nearly stalls, as the battery light flickers on and off, then recovers rev-wise.
This seems to mainly happen in 3rd 4th and 5th, but has happened in 2nd gears once. If i'm changing from 5th to 2nd or 3rd as I approach a roundabout this seems to happen. Is this an issue, or am I just letting the clutch up too late? It never used to do this, and it's very strange. It's not a greatly old car so I wouldn't have thought the alternator was on the way out just yet.
Should I perhaps try disconnecting the negative terminal of the battery for half an hour to see if the ECU can sort the whole idle thing out? Very hard for an amateur like me to determine the problem.
Thanks,
Dave.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I should add that I have just removed the negative battery terminal for 20 mins, and the car is sorting itself out idle-wise.
I have noticed that if I rev the car hard whilst idling (gear in neutral) and let the accelerator go, the car dies or nearly dies! I notice a few old newsgroup posts suggesting cleaning out the 'idle valve' as it may stick:
<snip> "> Sounds like the infamous idle valve sticking again. They do seem to require

Right with you Ian, and clean out the throttle body whilst your at it. If its not too bad, use a lint free cloth dipped in carb cleaner or brake cleaner. If its really dirty with a hard ring of carbon around where the butterfly sits, your best to remove it from the inlet manifold.
If after this and had given the ECU time to re-learn idle settings its still tempted to stall, we'd be looking at checking voltage at idle from the TPS and also base idle speed and possibly adjusting these alittle." <snip>
I do not know where the idle valve may be in my bonnet, any clues? What about the throttle body also? I would gladly clean these myself if I only knew how to get to them, or even what they looked like!
Complicated business...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The Throttle is the part the controls air into the engine.. find the air filter trace the big tube to the first metal part, note the cable to the bellcrank that moves with the gas pedal. Remove the flex tube and look in.. see the throttle plate.
The idle valve is there, also. it gates air around the throttle plate. Usually attached with two small bolts. But cleaning it usually only changes the symptoms or they return
--
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Okay, thank-you. I will try to clean the bits and bobs out, and fingers crossed this stops the un-smooth gear changes and the general nearly-stalling-ness that the car experiences.
I will try to price a new ISCV, but I imagine it could run into the 3 figure mark, which IMHO is a ripoff considering the technology it utilises!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.