You could try the solution I had come up with. Check it out here http://www.escortcabrioletclub.co.uk/forums/index.php?/topic/25440-roof-leak-now-fully-cured/
Happened to my bro's XR3i some years ago, I think IIRC we got away with just replacing the head, the pistons were still ok. It had just bend the valves.
Also check the wire coming from the alternator that links between the starter, if there is a break in this, it would produce the symptoms you mention, if you do a wiggle test, you may see the battery light get brighter or go out.
I had a 1.6 Ghia Orion without CAT as it was 1991 Registered. Although from 1992 all of them came with CATs as standard because of the law, it also sapped 3bhp out of it.
RS2000 is a easy swap, not much needed, as it was originally meant to be billed as XR+
You would need engine, fusebox, ecu, and engine accessory loom. The light/indicator loom does not need to be changed as its the same.
I have done the same.
Easy place to spot these guys, they always park their van on the opposite side of the road, usually a Transit/Sprinter size van. Also parked in unual places, whenever I see a van parked like this, automatically it rings alarm bells and 9 out of 10 times its a speed camera van.
It could be leaking through the window top seal, do you also have a wet seat. If not try clearing the drain channels from the sill by sticking something like a pipe cleaner size, but stiffer material like a coat hanger.
Also remove the front inner wing liners and clear the mud stored up behind.
Hi, gleaned from RS2000 forum. http://rs2000-16v.com/forum/showthread.php?25828-MK5-badge-positioning&highlight=badge+positions
Should be more or less the same for the XR3i
It was nice, made a huge difference. Although it was best in the Orion as the body was just a touch lighter and stiffer. The RS engine is more torquey than the zetec, which helps with the heavier cabby.
Go for the RS2000. many always go on about 2.0 zetec, but it is still not straightforward and would require more to make it work. The talk about it being lighter, it is not that much lighter. Besides standard power from it is about 20 down on the RS2k. Plus the RS has higher torque.
Check the cable is in properly first at the end of the speedo clocks unit. Then Check it also is in the speedo drive of the gearbox. Sometimes the nut could come loose, think its a size between 17-21mm.
As above the wire from the alternator that goes to the battery is breaking down, you may notice the light go out if you wiggle it, it may need replacing as it can cause battery drain.