hey people,

i bought a fiesta thats had a puma conversion (only the 1.4) took it back to my yard and it drove home fine on a 50 mile trip.

it was parked up for 2 weeks while i done the paintwork, and i bandages up the down pipe and tightened it as it was blowing. now when i drive it its over revving, and if i put my toe down its not gaining any speed and staying the around 4000 rpm..

i have changed coil pack and leads

plugs

egr valve

fuel filter

maf sensor seems to work

cleaned throttle body

cant find any air leaks

so now iv dis connected the manifold from the engine to see if the cat or down pipe is blocked, but its still running very rough when revved!!!

once i get driving as long as i down let the revs get too high and change gear at low revs it drives ok. but once upto speed in 5th, if its driving ok and i put my foot the the floor it willnot gain anymore power, but if i release the pedal a bit i can find the power again...........

please help!!

Your clutch may be slipping?

Your clutch may be slipping?

yes sound like the clutch plate.

ok i got it wrong, it IS a 1.7 conversion, and no its not the clutch as its not over revving it wont go past say 4000 rpm, then take your foor off the accelerator a bit and it will go round,, i put a new lambda sensor on it again today for a 1.7 and still no luck, but is running a bit better, think its still the lambda?

the maf sensor has been crimped on i will add, but would this matter.

yes sound like the clutch plate.

The maf is sensitive so could be that but your description still sound like clutch

if it was the clutch slipping it would still rev higher than 4k

have you any means of checking fuel pressure?

cheers everyone for the help, but seeing as i have changed nearly everything, i found that the only problem could now be the map sensor on the air box, i took it off, and the pins on the sensor that go into the box, one of them had black gunk on it, so a bit of brake cleaner and a careful cotton wool bud sorted it. jumped in, and ragged the hell out of it.

stress over, thanks for the comments though guys.