heavy cam syndrome

[timbo]

 

My EU3 1.6K performance at low revs/light load sites is abismal.

At start up from 1000 rpm to just below 3000 rpm at most load sites I get a quite significant vibration from the engine - there is only a couple of sites where the vibration smooths out. Once the eng temp rises it gets slightly better - but not much.

On driving, when I come off the throttle c. 3000rpm down or light loads I get a 'bubbabubbabubbabubba' sound from the exhaust. With this you can also feel the eng vibration in tune with the exhaust note. My best description is it is like the symptoms of an extreme cam - lumpy.

It makes the car quite unpleasant to drive at low load sites/revs (traffic driving).

As I am Ireland, I haven't got a chance to get the car set up on the rolling road.

I am using the spall.fig map which is closest to my setup I can find on your disc (5% fueling addition as using 45TBs instead of 42s).

My eng set up is based on the EMR kit (CCC feature article). I can't remember on who's cat 7 this was done. Who is that guilty party so I can obtain a copy of their map?

Or any other suggestions welcome - guys. I don't really have time to spend a week modifying the current map. LTL'03 is less than 30 days away & I would like to make progress in some improvement.

 

My set up:

1.6 K

std head

VHPD TB's

633 cams (timed with Johnty)

Verniers

M3DK

NO IACV - use slight throttle opening to achieve steady idle.

4-1 (long primaries) competition exhaust

 

[Goddard]

tbh i'd be skeptical if it was a fuelling proplem, i have had a few incorrect maps on my car and never experienced those symptoms. its the decel one that puzzles me, i found when too rich the car will judder at very low speeds on decel and be very snappy when going back on the throttle, but high revs were better. Hows your mpg? i also knew mine was too rich as i was loosing 20mpg

 

have you checked the cam belt? it almost sounds like its perhaps slipped a tooth or two, which they can do and produce an incredibly lumpy engine and lack of power. Either that or its SUPER RICH!

 

I tried a simlar map to my car which i found was no good, even though it was quite close engine wise. I have now mapped it myself, but I dont think it would be much help to you as its a 1.4 and no TB's (633 grind cams though) also regards other maps, they may be set on a different value for fuel pressure and injector size. ie the numbe,say, 30 on one map gives x ammount of fuel, but the same 30 on another map gives y fuel,you may just need to lean off the entire map by 5-10 points say?

 

i'm no expert but this is how i learnt and mine seems to run fine now.

 

hth

 

Goddard