problem with schrick cam

[dobbey1]

Hi can any one tell me if a schrick 284/272 cam would be lumpy on idle, i have just fitted one to my 325 cab and also had the throttle body bored out, when it is ilding it sounds and feels really lumpy , so bad that i have had to raise the idle to try to compenstate for this, but off idle its fine and there is plenty of acceleration there, is it a case of driving car for 40/50 miles to let the ecu adapt or is this the way it will be, any help would be great. it also smells rich out of exhaust.

[Fal_325i]

Mate if you've got a bigger cam, you will no doubt have lumpy idle, mine's the same, something your gonna have to live with i'm afraid.

Fal

[dobbey1]

cheers dude! just as long as i know

[Templ8e30]

Ideally you need to get it remapped, the cam and BBTB will provide more air but you need the correct fuelling to make the best of it all.

Cheers,

Iain T

[Andyboy]

How did you raise the idle speed? There's only one way to do this and that's on the thottle stop screw on the throttle body. This is bad news. What this will do is put the throttle position switch (TPS) out of synch and the car will be idling on the ECU part throttle/load maps - even rougher idle and horrific fuel consumption which is why your car stinks of fuel. The ECU thinks the engine is under part load and is telling the injectors to fuel to suit. The way to get around this is to screw in the throttle stop screw so the idle speed is around 1000 rpm. Then take the throttle body off, slacken the two screws for the TPS and nudge it back a bit. What you want is to hear the unit 'click' as you open the throttle - make sure it clicks the instant the throttle is opened. This click is the unit going from the idle to part load maps. Refit the throttle body and it should run a lot better!

[dobbey1]

cheers people !

[Brianmoooore]

Idle speed control should be left to the ECU and the ICV.
If you want to raise idle speed a bit, there's a small socket beside the ECU, coming off the loom to the ECU.
If you earth the purple/grey wire (I think) it will raise the idle speed a bit.

[Demlotcrew]

^ Yes that.

It would normaly be used with the Aircon.

But the idle should not be that bad!

Andrew

[Andyboy]

Idle speed control should be left to the ECU and the ICV.
If you want to raise idle speed a bit, there's a small socket beside the ECU, coming off the loom to the ECU.
If you earth the purple/grey wire (I think) it will raise the idle speed a bit.

Yes, but that was really for automatics with AC, foglights etc and a huge alternator load where putting it in D would make the poor thing almost stall. Having said that sorting out the TPS should sort it.

[--alpina--]

Put a Vernier pulley to advance the timing for quick throttle and pullaway but will compensate for losing a little top end, but you never do top end on streets anyway unless your doing airfield land speed record, like that prat who thought he was the don and crash, but the dark forces got hold of him and ended up in hospital,

And then chuck in a 2.7 alpina (copy chip) or any other which is already mapped to give more fueling then it runs sweet, mine does and am happy, phenominal power band with the 284` cam

But otherwise shrick cams compared to say, kentcams e.t.c. are better, kent cams and th rest are better for ford car and they really are lumpy.. if you cant get the right tune on your car then like Fal325 says you gonna have to live with it, anyway when you start the car up in the morning and its lumpy, this way the car warms up quicker


Regards


J.

[Turbo-Brown]

Or you could ditch the plenum and fit throttle bodies (and a mappable ECU) which would make all your lumpy idle problems a thing of the past

[maxfield]

Or you could ditch the plenum and fit throttle bodies (and a mappable ECU) which would make all your lumpy idle problems a thing of the past

And then you'd want more then go with a big cam and get a lumpy idle all over again

[Turbo-Brown]

By and large you should be able to do pretty much anything cam-wise once you've switched to correctly sized ITBs.

Just for heaven's sake don't fit carbs!

[dobbey1]

well now im totally confused of what to do next

[wildeian]

Mine is fine, not lumpy at all. A Zone chip would probably sort it out, try asking Ant.

[Andyboy]

well now im totally confused of what to do next

Just do what I told you to do! Seriously - if you increased the idle speed on the throttle stop screw the TPS will be way out and it will just stink of fuel. Sort it out like I've outlined and it should be okay. You will have a lumpy idle as the cam you've got it quite wild (An Alpina cam is only 268/270) so you're not going to have a silky 750 rpm idle I'm afraid. But it should idle okay at around 900-1000.
Chips etc are all very well but you need to get the basic settings right first.

[buster]

i had the 284/272 on mine with the BBTB.I had one of the zone chips also which raised the idle speed to 950 rpm.
It idled perfect and the TPS switch was obviously set up properly.So id try and get the zone chip with higher idle speed if i were you,as well as setting up the TPS switch properly.

[dobbey1]

i will set up the tbs this weekend and see how it runs , then go from there , cheers for all your help people!

[Andyboy]

Why don'y u give Ant a call. He's only in snod and it's not a big job.

[Ant]

Tis true, I'm jnct 4 M20, not a million miles from Medway