Won't rev past 5000rpm

[DuncanM]

Hello,

I've been busy trying to get my car running well enough to pass the MOT.

We changed the coil packs today and the fuel filter, with this the car is running much better and maintains an idle with the throttles at 20%.

Thing is, on a r quick run out the car feels ok at low revs and then just runs out of steam around 4500rpm. Just when you expect it to go mad and fly straight to the redline line it seems to hit an invisible wall at 5000rpm.

I have new leads hopefully turning up tomorrow and will check the plugs when I change the leads.

Please please please reply to this Topic if you have ANY info to add that you might think will be useful.

Regards

Duncan

[jammy_basturd]

Have you plugged in a laptop with the ECU software to check for any faults?

[BCA]

Had a similar issue on another car, definately sounds plugs/ leads related to me.

[DuncanM]

Hello,

Yes, laptop has been plugged in all the time I've been doing this, got the idle down to 20% both banks.

Ben, I really do hope it's the leads .

Regards

Duncan

[BCA]

Well the symptoms are the same as I had - one of the HT cables didnt seat correctly on the plug and made a "click" but wasnt fully on... the result was a car that idled perfectly* but would not rev out - it felt strangled. Incidentally this wasnt a Cerbera, but a Smart car, where as it is only a three cylinder, the issue was rather more pronounced! After a firmer push on the HT lead for a second "click", it worked perfectly once more - new HT leads will be fitted to that car next time I see it (its not at our house.) but thankfully all is fine!

• it idled fine as the set up is a twin-spark set up per cylinder, so it was ok until it was overworked with revs/load.

Edited by BCA on Monday 20th September 17:58

[FarmyardPants]

Blocked cats?

[Gazzab]

crank sensor?

[Tanguero]

Cam timing?

[Mr Cerbera]

Roll of Axminster stuck under loud pedal ?

Tabby Cat sleeping in the silencer ?

Sorry !

Edited by Mr Cerbera on Tuesday 21st September 09:52

[DuncanM]

Thanks for all of the replies, I'll update with the solution when we get it running properly .

Duncan

[Tanguero]

Coil pack has to be a suspect!

Yes I did read that you had just changed them - but it wouldn't be the first time that even the Bosch ones were bad out of the box.

[BCA]

Tanguero said:

Coil pack has to be a suspect!

Yes I did read that you had just changed them - but it wouldn't be the first time that even the Bosch ones were bad out of the box.

This too.. coil packs, ht leads, spark plugs. Its somewhere in that lot.

[DuncanM]

Hello everyone,

Having looked into this further it looks like it is cam timing!

I'll update this thread once we have sorted it and let you guys know if it solves the problems.

Thanks to everyone for the replies .

On a brighter note, I have driven the Cerb about over the last couple of days and it simply is THE BEST driving experience I have ever had!

Ha Ha Ha! Even running like a dog, with rusty brakes and old tyres, the Cerbera is the single best driving experience I've had.

A privilege to own .

Duncan

[FarmyardPants]

Silly question maybe, but how can the cam timing change, without having the engine out etc?

[DuncanM]

Not silly at all!

We've just had the engine out for a rebuild and are trying to get it to run right by fault finding .

Thing is, when it first burst into life it ran at a perfect 1000rpm idle which fooled us into thinking everything was a ok.

Having read up some more about the cam timing we feel we've not got it spot on so will be checking and correcting at the next opportunity.

Regards

Duncan

[FarmyardPants]

Ah that makes it quite likely then

[itiejim]

The cam timing is adjustable via slotted holes in the cam shaft gears. These need to be removed to shim the cams (and set the valve clearances) so, if you're not careful, they can be put back together inaccurately.

[Tanguero]

DuncanM said:

...Having looked into this further it looks like it is cam timing!

Having just done a 12k service and reset the cam timing on mine - I was horrified as to how much it had crept out in a couple of years. It makes a huge difference to have it spot on.

Edited by Tanguero on Wednesday 22 September 09:05