1999 P38 hesitates around 4000rpm

It drives fine up until you plant your foot, its asthough it does not want to go past 4500rpm... Even if Sports Mode is pressed the same thing happens.
At stand still I put her into Park and revved the engine and it does the same when no gear is selected too...
Anyone had this problem or know what it is?

Your help will be greatly appreciated

Thanks
Daz

is it a petrol or diesel? sport mode wont make a farts worth of difference as that only changes gearbox selection points ie when it changes.
shouldnt rev the engine in park a good way to f**k the zf auto gearbox!

If it's petrol I would check the fuel pressure. A 4.6 Thor should be about 55 psi. The test point is to the right of the engine as your standing at the front looking in and right at the back.

Sory guys, its a 4.6. The car drives fine and to be fair I only noticed that its hesitating as I was on the motorway last night and decided to overtake sharpish, so planted my foot too fine it really did not want to rev and seemed to be holding the gear at 4500 rpm, so I shut off slightly and it the changed gear straight away. I pulled into the next services thinking it was my gearbox that was the problem. So when in Park I decided to see if the engine would rev up without being in gear, which it did until 4000-4500 rpm then started to sort of judder & hesitate is the best way I can dedcribe it. That to me then took the gearbox out of the equation, so thought it kust be an engine problem. Though there is no engine management light on at all.....


Hope that explains my problem a little more.

Thanks again
Daz

rewmer said:

If it's petrol I would check the fuel pressure. A 4.6 Thor should be about 55 psi. The test point is to the right of the engine as your standing at the front looking in and right at the back.

Click to expand...

So is it sort of a tyre valve I am looking for? Do I check the pressure with a tyre gauge? Will it be 55psi at tick over, or do I need to check the pressure at different revs to see if it drops ?
Cheers for you help

The other thing I forgot to mention I only got 15 mpg as an average over 120 miles motorway miles sitting at 70 mph most of the time which is less than I usually get. Thought that may help in the diagnosis
Cheets again Guys

I have been told today it could be Air Flow Meter. Dowa that sound like a possibility?

Cheers