Engine issues on project: Chav running very flat

[Djw Dave]

I bought chav a few weeks ago now with the intent of turning it into a track day/b road car.

Project thread here: http://www.cliosport.net/forum/showthread.php?587048-Project-Chav

I bought it knowing that the light was on. Checked it with the code reader, it had 3 codes, O2 sensor, knock sensor and idle control valve.

The control valve was not plugged in after a plug change so that was a easy fix, the O2 sensor had bad wiring so a re-wire seems to have fixed this (needs more running time to confrim) and the knock code has never came back.

the thing is it's very flat up the rev range to 3.5-4k then it takes off???

No other codes have come back on, and its probably a stab in the dark but any ideas??

Could being timed wrongly do this?

A blocked cat?

Would the knock sensor fault do this??

So many questions i know, but hopefully some one wiser than me will have the answer.

Thanks in advance guys

Dave/John

 

[Russ_16v]

Id look at cam timing mate, usual culprit, and in my experience they are flat until higher revs - I think my projects timing is slightly out.

Plus if it was chav owned, the chances of it being done properly is low.

Get it on a rolling road, the shape of the graph normally give a clue to the timig

 

[Cookson]

I agree, timing probably out. Buy a pair of cam seals and have a look

 

[Djw Dave]

Cheers for the advice guys. Will this have caused any damage and will continuing to use it make it worse?

 

[Jonny1*2]

as longs as the valves don't drop you'll be ok, but it's advisable to get it sorted asap. It's more of a problem with aftermarket cams where lift etc is greater, so there is a risk of valves hitting pistons.

 

[Djw Dave]

No aftermarket cams on this one. I'll get it checked over asap then.

 

[Russ_16v]

Cheers for the advice guys. Will this have caused any damage and will continuing to use it make it worse?

They can do, but normally it's only slightly out, which gives poor performance (Thats why half pf 172's only make 150something bhp) so im sure if you can't here any worrying knocking/tapping noises then she will be fine fella

 

[Djw Dave]

Cheers guys got a mate coming to have a look at somepoint this week.

 

[Djw John]

It slightly lumpier than they normally are as well. Everything is kinda pointing to the timing isnt it?

 

[MicKPM]

Yep, afraid so and for £12 in parts its not worth ignoring something that's easily confirmed/denied.

Mick