Hi Guys. My 2008 mondo hesitated when it's cold and usually going down hill. Also noticed it when on cruise control. Any ideas what might be wrong? I'm thinking it might be injectors. Any advice will be welcome. Thanks.

have you tried new fuel filter?

Yes. I changed it along with oil and oil filter 2 weeks ago. It doesn't happen all of the time and usually when I start up the car I know by the sound if the drive ahead is going to be like that or not.

I think you'd be better going to a local ford dealer or someone who has a Ford IDS vcm. they can plug it in & get all your live data etc. It'll tell them exactly what fuel pressure,sensors etc are returning. It should only cost a max of £40 (ish)

is it the same with or without cruise?

It's the same with and without cruise control. It can happen anytime but I've noticed that it happens a lot going downhill.

if you're goin downhill,& put it in neutral,can you rev it right up? does it hesitate then?(the revs i mean)

faulty maf sensor can cause this but so can lot of other things. get the data readings read i'd say.

Have you tried resetting the ecu?

I must give that a go and get back to you on it.

I actually just took out the MAF sensor and they don't look too shiny but rather dull and brownish. Can this sensor be cleaned or not as the wires are semi enclosed in the sensor housing. This is one like the one in my Mondy

got to admit,Ive never come across this particular type before.Id get some electrical contact cleaner. I wouldnt use carb cleaner as it degrades plastics.Give it a good scoot & let it dry out. Dont aim the jet of cleaner directly at the wires though & dont touch them with anything,as theyre very delicate.

@stooge75. Ok. I tried revving while in neutral going downhill. No hesitation but... I revved to 3000rpm and released the throttle the car continued to rev to 4000rpm before coming back down. I did this 3 times and the same each time. Any wiser?

personally if it was mines I'd want to get it scanned on a dealer level Ford IDS vcm. the software they have will tell them exactly(or it should) what sensor isnt working properly.It could be 1 of too many things & its no good chucking money & parts at it without knowing what these results will be. It'd be worth the £40 (approx) to have it done.

It could be anything from clutch sensor,(had similar prob on own car but only when changing gear but have been told from ford that if clutch pedal sensor elecs are sticking it could also cause probs when not pressed),accelerator pedal(fly by wire),air sensor,idle control,etc

It would be worth getting it done though i think

Yeah. Will defo have to get that done. As soon as I get a chance to pop over to a ford dealer I'll update on the outcome. Hopefully nothing too serious.

Well I'm just out of the ford garage and had the full diagnostics done. Took 90 mins so it was thorough. One if the injectors was leaking fuel. Thankfully my problem was small and it got sorted on the spot. Thanks for the input guys.

what was the final bill?

It was €75 for diagnostics and no charge for fixing the injector. Must've been a minor fix then.

wow, that is pretty damn impressive for a dealer?

damn good price also.wonder if the injector was dirty & just needed cleaning.

Yes. I was delighted with it. Hopefully that's the end of it now.

Not sure what was actually the problem only that it was leaking fuel and that he fixed it.

perhaps where it was leaking fuel from the injectors, the engine was slow to respond when you took the foot off the gas. there wasnt enough fuel and too much air, so immediate fuel adjustment may have caused knocking or stalling, so this may be why the car froze at high revs then eventually caught up?

Just got the report sheet from the garage. There was a leak off the pipe on injector number 3. It was removed cleaned sealed and retested. Great deal.

@ jeebowhite I'd say your bang on there mate. In hindsight it all adds up.

Well, glad you got it resolved, let us know if it changes. I will mark this thread as resolved for you, in case someone comes along, and needs an answer to it!