Non Mercedes problem.ford fiesta zetec

[chrisbrad66]

Hi all, got a problem with a clients car and it's got me stuck, it's a 1997 fiesta 1250cc zetec, if you slowly press the accelerator it will rev fine albeit with a little delay, if you stab the pedal right down fast it will only rev to approx half speed and it just will not rev any higher, it's as though it's hit a rev limiter, the cat and downpipe get incredibly hot and glow a very bright orange, i've checked the exhaust and cat for a blockage, all ok. Put my code reader on to check any fault codes and theres nothing stored,no management light lit and all the sensors seem to check out ok. Checked for fuel blockages but all appears ok so now i'm stumped? any one come across this before? any help would be appreciated. Thanks

 

[MOR8A]

At a guess it is single point fuel injection? I would take the bits off to get to the throttle body and run it like that, then do the stab and have some one standby with some petrol in a container with a fine spout. You can then add some extra fuel to see if that makes any difference. It's a bit of an art as if you add too much fuel it will just bog down. The whole getting very hot sounds like it's running lean. Try that and see if it is fuel starvation, knock one potential issue on the head and then move on to the next. Got to go to the pub now, good luck.

 

[chrisbrad66]

Thanks for the advice, tried swapping crank and cam sensors to no avail, tried your method too but still no joy, finally i removed the MAF sensor again and noticed some tiny particles of dirt on the element coils,which i missed the first time round!! damm it LOL, i carefully brushed the coils with solvent and refitted the MAF and it runs like a good un again, thanks for the help.

 

[MOR8A]

Cool. Glad it all worked out.