P38 V8 low power, sluggish, what do I try?

Hi all.
I've had a search, but I'm struggling to find answers to what I suspect is pretty common...

The car is a P38 4.6 V8 2000.

I've noticed this problem developing over the last 2-3 months, and it seems to be getting progressively worse. It started off feeling like a misfire (or similar). It is now just generally low on power and doesn't want to pull up hills - at all.


So far, I've:

• Pulled all the plugs to look for anything 'odd' - all plugs looked ok.
• Made sure all HT leads were pushed well on to the plugs.
• Taken off the MAF unit and given all the connectors and insides a good spray with electrical contact cleaner.

At first I thought this had helped - but it hasn't.

I then disconnected the MAF sensor lead completely, and ran around like that for a day - no change.

This morning (MAF lead still off), and car stone-cold, I tried to set off to take my little-un to school, and the car did about 50yds before losing all power (half way across a junction!). I limped to the side of the road, plugged the MAF lead back in, and the car started to go again - but still low on power and not pulling very well (but at least it was going!).

I'm not really sure what this tells me, and I know I could throw a whole bunch of parts at it to try to help, but I really could do with a bit of expert guidance to point me in the right direction..... Please!

I don't have any kind of fault code reader, and I don't know anyone who has....

Can anyone help?

Cheers in advance.

Really needs to be code read,could faulty coil pack,lambda sensors etc,best get live data reading ,maybe someone close by from here with a code reader that will help,try lz rescue at top of main page.

dove said:

Really needs to be code read,could faulty coil pack,lambda sensors etc,best get live data reading ,maybe someone close by from here with a code reader that will help,try lz rescue at top of main page.

Click to expand...

Thanks for the reply Dove. I was hoping there was a magical solution... but clearly not!

Having mulled my options, I took it to my local independent this week to get it on his computer, and that rarest of things happened - an immediate and accurate diagnosis! One of the HT leads had died.

He had a spare kicking around, and £80 later my car has got it's mojo back! Its is almost worth running round in a poorly V8 for the great big grin it puts back on your face when you get it sorted again. Fab.

So, what have I learned?
- Not every V8 repair has to cost several hundred quid.
- V8s sound great when they're running well!
- If the problem is in the ignition system, get it on a computer.

Thanks again.
Turtled.

This happened to me - bought a 2000 P38 V8 which had a misfire under load, went to a local Indy ( Gigglepin) turned out it was leads and coil pack, this cured the misfire but it still would not rev freely, although there was no MAF fault shown and unplugging the MAF stopped the engine on tickover diagnostic showed that The MAF output was incorrect new one fitted and I have a different car.