I have a 1985 ZL Fairlane. I have recently replaced the auto trans with a ford 4 speed manual. The car runs well except for one problem, when it is decelerating (especially when going down a hill) the car is very jerky, like the opposite of a surge it lags and releases and lags and releases.

I have been told I need an eec4 for a manual car which I have recently tried but while it fixed the jerkiness of the deceleration the car ran real rough and there is a strong fuel smell indicating it is running rich, so I have taken it back out.

So here is my questions, does anyone know of how to fix the deceleration problem with the original auto eec4? or does anyone know if the manual eec4 is needing some extra signals to allow it to run properly?

Some extra info, my car was originally a leaded model so it doesn't have a knock sensor, the eec4 that I got from the wreckers has that it came from an unleaded xf (it also indicates on one of the stickers that it is for a mondeo, I will post the part number tomorrow to see if anyone can confirm whether it is or isn't a falcon eec4).

I have searched these forums and whilst there are some threads on conversions I haven't found one that answers my issues.

huh i thought the eec4 was EA to ED computer system????

i only thing i can think of maybe there is some astray with ya allerator calbe or tps or something

The number on the eec4 is 86DA-12A650-B1A does anyone know if this is an XF computer?

eec4 is a generic name. It will need to be one for an XF

yes this computer is from a xf 4.1 5 speed manual efi model i am looking for one of these at the moment but cant find. Let me know if you want to sell it

I cannot see why you would need a manual ECU. XF's ran a mechanical auto, not an electronic auto.

Yes I'll have a look in my shed to see if I can find it, I'm sure I still have it somewhere