Idle Control Valve

[wrinx]

Is there a point where the ICV wouldn't be able to function correctly...for example, I have a "medium Street" C&B inlet camshaft and the car really struggles to idle for the first 5mins or so; it makes driving the beast a bit dangerous at first unless I have time to let it warm up at home first.

Is the ICV being affected by the changed inlet opening times of the camshaft or should it be able to cope?

I've cleaned it a couple of times and all seems well, but if it's FUBAR....?

wrinx

[wrinx]

Just checked, I replaced the ICV some time ago but no change...forgot about that :roll:

Any other thoughts?

wrinx

[corriedw]

Change the cam timing a little so that there are less overlap(time intake and exhaust are open together). The overlap cause little pumping at idle speed and without vacuum in the intake manifold the engine will not idle at normal speed. You will probably also find that the brake booster doesn't much with braking at idling as well.

It is difficult to know what is best if you are not on the dynometer. I don't know the particular cam, but we found that om most cams, we moved the intake cam 2 deg slower for every degree you make the exhaust faster. You can let yourself lead by the std cam timing of the Integrale, meaning the exhaust valve close at tdc. But this will effect the top end power on an NA engine, but my opinion is it does not effect a turbo engine at high revs as long as the boost holds.

I don't like wild cams on turbo cars, but we made 276 deg and 284 deg cams work on turbo cars.

[wrinx]

I can't recall the spec of the cams but 276 rings a bell.

The cams were set to the original timing marks as recommended by C&B but the car got worse.

There might be another reason for the fault but the cam has also robbed some low down power I might take it out again and return to the standard cam.

wrinx

[wrinx]

Found it - Columbo & Bariani "medium street" inlet cam, 10.46mm lift with 276deg duration.

winx

[Suzumushi]

Found it - Columbo & Bariani "medium street" inlet cam, 10.46mm lift with 276deg duration.

winx

dyno, and reprogramming ecu will help for sure, in my opinion

regards

W

[wrinx]

Yes, I think you're right. Not sure I can be bothered with all that now :lol:

I last had a quote of £500 but that was several years ago now, bound to be more now :eek:

wrinx

[corriedw]

276 deg is wild for a fast street NA car Vauxhaul(Opel in SA) Superboss had a similar cam. But it is crazy for a turbo car.

The standard cams for a Q4 is 223 deg intake and 210 deg exhaust with 8.8/7.5 mm lift. VERY big difference. What you could also try is the std Lancia intake cam on the exhaust, with the exhaust valve closing on TDC. That should solve a lot of these problems.

Please let us know what you do and the results.

[wrinx]

But it is crazy for a turbo car.

:lol: Thanks for confirming, so it is the cam causing the problem...good, it's coming out then!

wrinx

[corriedw]

In my opinion the std Q4 cams is too calm. That is why the boost pressure run so high on these engines, the air struggles to get into the combustion chamber due to the small lift. I like 236 deg 9.6 lift

If I were you I would really try the C+B cam on the intake, with the Q4 intake cam on the exhaust side.

[Suzumushi]

Yes, I think you're right. Not sure I can be bothered with all that now :lol:

I last had a quote of £500 but that was several years ago now, bound to be more now :eek:

wrinx



For that kind of money (little less i guess) You can have modified ECU that can be reprogramming online, so basically most of corrections You can "do it yourself" :)

regards

W

[wrinx]

Me...with buttons to twiddle :eek:

Perhaps not wise :lol:

wrinx