Fiesta 1.4 petrol, 2003 with the dreaded limp mode about twice a week, where do you start ?

 

mike 

Buy a code reader of feabay they don't cost to much then read any codes and post them

up here on the right forum someone will then be able to help

Quote

 

This company

https://tunnelrat-electronics.fwscart.com/

has been recommended many times on here. I bought the USB modified one from them.  It has a switch so you can switch between the 2 computer type things that modern fords have (perhaps not the exact right terminology). 

the software you need (eg.Forscan) can be downloaded free

try to unplug your maf sesor when it happens and check if it`s gone if yes clean or replace it.

2 hours ago, Tuha said:

try to unplug your maf sesor when it happens and check if it`s gone if yes clean or replace it.

to elaborate, a lot of cars will run without a maf sensor connected. the ecu then uses a default reading which it computes from other factors (eg. throttle position, air temp), so if the MAF is dodgy, it may run better with no MAF than with the faulty one.

I do not know if your car definitely has a MAF sensor.  I had a 2001 Focus 1.6 petrol. I searched for the MAF as I did not think it ran spot on. Couldn't find it. Turns out that car never had one.

On 9/12/2017 at 2:10 PM, isetta said:

to elaborate, a lot of cars will run without a maf sensor connected. the ecu then uses a default reading which it computes from other factors (eg. throttle position, air temp), so if the MAF is dodgy, it may run better with no MAF than with the faulty one.

I do not know if your car definitely has a MAF sensor.  I had a 2001 Focus 1.6 petrol. I searched for the MAF as I did not think it ran spot on. Couldn't find it. Turns out that car never had one.

as far I know almost every car have MAF sensor with EFI(electronic fuel injector) :)

that's what i thought until I had that 2001 1.6 petrol focus. it wasn't missing like someone had removed it or modified, it was designed without one. I don't know if it was only certain year that did not have them

this mentions it:

https://passionford.com/forum/technical-help-q-and-a/385782-focus-mk1-maf-sensor.html

The role of the MAF sensor (air metering) can indeed be achieved by measuring pressure, temperature and a few other things - it's not as accurate but is arguably more robust.