Andrew,
It took a couple of minutes to guess you have an '87 (and a mechanic).
You could update your User CP? (top of page)
You used the Fuel-08 procedure:
http://www.clarks-garage.com/pdf-manual/fuel-08.pdf
It could be a blocked/dirty ICV/ISV.
From under the intake air tube--there is a hose to the ICV/ISV . Shoot some Gumout Fuel Injection-Air Intake and carburator cleaner in the tube with the engine off. If the ilde improves-you have a dirty ICV- You might get better results if you can get the hose off at the ICV/ISV itself. Then, with a straw, spray some more Gumout in. Otherwise you should take it out and clean.
If you have good idle at temp, it could be the DME coolant temp sensor when cold. The sensor when cold tells the DME to all fuel during warmup.
Or a bad O2 sensor.
GL
John