Hi everyone,

I am new to the forum and hope someone can help ?

My Mondeo 1.8 Zetec 2000 year model developed a problem where it wouldnt rev higher than 2500 rpm when driven but would rev higher when in neutral and if you try to get the revs higher it just sounds asthmatic like its starved of air so we suspected a blocked fuel fliter. It was overdue a service anyway so we changed the plugs, air filter, oil, oil filter, and fuel filter but it made no difference. It was due its MOT so while there i had the EGR valve cleaned out which i hoped would fix it, but it didnt.

Then i noticed today that when i start it from cold and drive it hard it will nearly red line on the tacho but as it warms up it wont rev above 2500rpm again. Other than this it runs fine, tickover is normal, fuel consuption has not changed and emmissions where fine when it went for its recent MOT.

I would appreciate any help and advice as i dont want to spend money wastefully,

Many thanks, Bob.

the only real difference between cold running and warm running is the mixture. i would say that during warm up when the mixture is made richer, u have no problem which sound to me that the mixture could be too weak when the engine is warm. uve already checked the intake ie the air filter, try for leaks in the pipe from the air filter box to the engine. also cleaning the maf sensor that is on this pipe monitors and adjusts the mixture. try this link.

http://fordwiki.co.uk/index.php/MAF_%28Mass_Air_Flow%29_Sensor_Clean_130_TDCI

i know this is a tdci reference but the position and cleaning method are almost identical.
try it as it costs nothing!

[quote name='chris bowman' date='06 March 2010 - 04:29 PM' timestamp='1267892393' post='69146']
the only real difference between cold running and warm running is the mixture. i would say that during warm up when the mixture is made richer, u have no problem which sound to me that the mixture could be too weak when the engine is warm. uve already checked the intake ie the air filter, try for leaks in the pipe from the air filter box to the engine. also cleaning the maf sensor that is on this pipe monitors and adjusts the mixture. try this link.

http://fordwiki.co.uk/index.php/MAF_%28Mass_Air_Flow%29_Sensor_Clean_130_TDCI

i know this is a tdci reference but the position and cleaning method are almost identical.
try it as it costs nothing!
[/quote]

Thanks for the response and link, when looking up info on cleaning the MAF sensor it seems you need to be careful what cleaner you use, so i went to Maplin and bought their PCB Cleaner as it says it leaves no residue (it did leave a little but you can simply blow it off).
Unfortunately after cleaning and reinstalling it is still the same, looking up this kind of problem in forums highlights that this is a reoccuring problem on lots of makes and models (

sorry it hasnt worked may be time to read codes at garage

check the rubber pipes on the crankcase emmision system...the earlier models had t piece section that always split giving these syptoms...this has been replaced by a straight section but it might be worth checking the rubber pipes for a split

quote name='FORD-PARTS-CENTRE' date='07 March 2010 - 06:19 PM' timestamp='1267985345' post='69363']
check the rubber pipes on the crankcase emmision system...the earlier models had t piece section that always split giving these syptoms...this has been replaced by a straight section but it might be worth checking the rubber pipes for a split
[/quote]


look to the rear of the engine behind the throttle body and look for this pipe with the engine running yo may find that its collapsed and the bend is sucking together another possibility is the pcv valve may be stuck follow the hose to a metal pipe then round to the front of the engine right under the exhaust manifold to the right youll see a pipe with a small bend connecting to a metal thing pull that up and youll find this is the pcv valve

Hi all,

I am disapointed that nobody really who has had this severe problem has given a solution.
I've found myself in the very same position for months now but with my wife in a far away hospital, it just recently became critical.
I too changed the air filter, fuel filter etc. All to no avail.

I had a strange rattling sound from the front end of the exhaust and an awful lot of water spitting out the back box so I took my car into my local garage and had the middle and rear sections of the exhaust changed, but still no cure.
I asked them what they thought the problem was and they answered; "You didn't pay us for that!"
I was supremely unimpressed.

My car rev'd OK in neutral but stick it in gear, drive and you can't get above 2500 revs or at most 30 mph - worse on hills. It seemed the car had kangaroo petrol.
The harder you pushed the accelerator, the worse the problem. The engine was choking itself.

I am super annoyed though, not just that an obvious solution I couldnt find or that a definitive solution hadn't been posted here, but at the garage who replaced most of my exhaust, as the problem was the catalytic converter; not a million miles, just a few inches in fact, from the parts they replaced.
My M.O.T. 30 day window opened up today and not only has my car now had this long term problem fixed but also a new M.O.T.

I don't know if you have similar or identical symptoms to mine but if you do, please don't waste money on filters, plugs etc. or a new back box, mid exhaust section etc, try the cat.

Good luck!
If only someone had posted this before, I'd have saved a fortune.

I hope I can save you one too.

I eventually sorted this problem, in the end the car was undriveable and i couldnt get home from work so i called the AA out, they diagnosed a blocked Cat in the exhaust. I drilled some holes in it and it worked fine thought it did sound like a turbocharged hair dryer.
So a trip to the exhaust depot and £139 later its all fixed and revs fine.

[quote name='libbynbob' date='08 April 2010 - 06:38 PM' timestamp='1270747702' post='76889']
I eventually sorted this problem, in the end the car was undriveable and i couldnt get home from work so i called the AA out, they diagnosed a blocked Cat in the exhaust. I drilled some holes in it and it worked fine thought it did sound like a turbocharged hair dryer.
So a trip to the exhaust depot and £139 later its all fixed and revs fine.
[/quote]

ah the blocked cat usually there are symptoms prior to it collapsing like gradual loss of pwer and electro star water from the exhaust is normal so why they changed youre centre section is frankly beyond me whaen an exhaust cools a natural reaction is that it causes water in the exhaust even burning the petrol through driving does this so water from the exhaust is not a reason to change it and the mechanic should have known that

I think you have solved my problem I have an Xreg 1.8 and it wont rev above 1000-1200 revs thought it was fuel but drained tank and put clean fuel in and no change. Also connected to diagnostic tool no faults shown. Sounds like its gasping for fuel and air. Have noticed not much pressure from exhaust pipe. Will check cat now. Fingers Xd