Running Problems....

[AllezWasps]

Over the past month or so my 4.5 has been what I would describe as a bit lumpy at low speed or when accelerating with about one third to half throttle. It has been an intermittent problem and it almost feels as if the car has been running on 7 cylinders. Under acceleration it has been hesitant (best described as if there is a blockage of some sorts) but then all of a sudden the problem clears.

Two days ago it seemed much worse. The car didn't like pulling away from stationary (very lumpy) and having been out for a good 40 mins (i.e engine was properly warm) I returned home and left the car idling on the drive (normally idles at about 800-1000rpm) and it cut out. I restarted it and blipped the throttle, took my foot off the throttle and it immediately stalled again. This happened a couple of more times before I started it and revved it to about 4000- 4500 rpm when it idled as normal.

I am thinking ignition coil but wanted to know anyone else's thoughts...

[itiejim]

Symptoms are similar to when my coil went down. They do suffer down there in the middle of the V and get very hot, therefore I'd really consider them a service item.

Bung a pair in and see how you get on.

[brakedust]

I had the same problem with mine, turned out to be the coils and one of the HT leads was arking against the engine, and one of my TP's was knackered!

If you have the AA breakdown warranty thing they will pay for it all, so only cost me £50!

[pmessling]

Sounds the same as I had. Although I never narrowed it down to one specific thing as I changed the coils, plugs and leads. But solved the problem and runs great

[The_Edge]

A classic, but, always worth checking the big fuse...

While back now, but I had similar random problems which felt like power loss, but were a badly eroded fuse making intermittent contacts as it heated/cooled etc, but with no obvious pattern at the time.

Edited by The_Edge on Monday 3rd January 19:28

[AllezWasps]

Thanks for the replies.

The HT leads were changed a month or so back. Will check the fuse but I am leaning towards the coils.

What with that and the 450SE needing a new starter motor, not an ideal way to start the year!

Matt

[AllezWasps]

Coils have been changed.

It is like a different car. I reckon it was about 20% down on performance beforehand. It is now lightning quick again and so much smoother.

Very very happy.

[brakedust]

AllezWasps said:

Coils have been changed.

It is like a different car. I reckon it was about 20% down on performance beforehand. It is now lightning quick again and so much smoother.

Very very happy.

Good to hear you got it sorted fella!