Hi Brits.

I own a ford escort mk4 cl, modded to a 1990 spec Xr3i Efi engine.

It have some strange issues tho, i have no clue how to fix it.

Lets start at the beginning:
When the car have been turned off for a couple of hours (typical 5+) it starts "okay" runs okay for a couple of yards and then it starts to "jump"/driving rough. It starts jumping around like im zapping the gaspedal on/off, but ONLY when I drive it nice, if i just floor it (even at 1500rpm) it stops jumping. untill i stop flooring it, then it starts again. After I pass 1km it stops acting weird but.. Now its still jumpy when i drive economical or hold a certain speed (like 60mph) ,, Only way i can get around in the city when im going back from work is to drive between idle and full throttle + raping my already worn clutch if i wanna avoid the damn jumping!!

When i floor it, its like its laggy? It waits for ½-1 second before taking the throttle and then gives a huge jump feeling like the engine is gonna fall though the bottom, this is only when i kick it! if i take 2 second and increase the throttle smoothly theres no jump

Bonus info:

No problems in idle. (sometimes it goes swinging 100 +/-)
Engine = Cvh 1.6 8v efi. WITH lamdba/hego sensor

Obs: Also when its cold, it runs for like 1-2 seconds on the starter, sometimes when it hot i starts on the button? :S

So what is it? Something with the ecu? vacuum? Worn fuel pump?

Im sorry for my bad English.

Hope you can understand my text.