Bozz Posted February 28, 2006 Share Posted February 28, 2006 I have a standard 1.6K SS with Piper verniers, DVA 'adjusted' standard plenum and throttle body. Since the work was done I've only driven a few miles but have noticed the following changes to the engine's characteristics:- 1.Throttle response IS dramatically improved and feels like it's producing another 20bhp. 😬 2. Exhaust noise is much deeper and much more of a 'bark' (std short 4-1 ☹️) 3. Idling is less smooth (hunts s bit) but not dramatically so, but also seems to want to 'fast' idle at times rather disconcertingly. 4. Induction 'hiss' when throttle closed such as between gearchanges seems to have disappeared ( I quite miss this ☹️) Any thoughts, comments from the oracle that is BC Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted February 28, 2006 Support Team Share Posted February 28, 2006 Points 1-3 are almost certainly as a result of the corrected cam timing. Can't help with 4 although at a guess in fettling the throttle body a "problem" was cured. Yellow SL #32 Link to comment Share on other sites More sharing options...
CageyH Posted February 28, 2006 Share Posted February 28, 2006 I have a comment.... Fit throttle bodies and a proper exhaust Then see what the throttle response is like 😳 Link to comment Share on other sites More sharing options...
Bozz Posted February 28, 2006 Author Share Posted February 28, 2006 The induction noise used to be very noticeable - a loverly hissing 'slurp' as the throttle was closed between gearchanges, I supose this may be as a result of the throttle butterfly 'reprofiling'. Jenvey's here we come 😬 😬 😬 😬 Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Bozz Posted February 28, 2006 Author Share Posted February 28, 2006 And I only went to DVA for a head gasket job 😳 Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Mr Locust Posted February 28, 2006 Share Posted February 28, 2006 Bozz, Dave most likely opened up the throttle stop screw so that the engine is less reliant on the IACV at idle as more aggressive cam timing can confuse the MAP sensor. The hiss before was probably air flowing through the IACV. Ian Green and Silver Roadsport 😬 Link to comment Share on other sites More sharing options...
CageyH Posted February 28, 2006 Share Posted February 28, 2006 I only went to have vernier pulleys fitted Link to comment Share on other sites More sharing options...
Bozz Posted February 28, 2006 Author Share Posted February 28, 2006 Cagey H You know that and I know that but does SWMBO know that............No ❗ Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Bozz Posted February 28, 2006 Author Share Posted February 28, 2006 Ian Actually I don't think Dave did adjust the throttle stop so is it possible that my IACV is sticking? Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
CageyH Posted February 28, 2006 Share Posted February 28, 2006 I am lucky, SWMBO knows it is my car, my money and is happy as long as it keeps me out of the house She also lives in France, so can't see under the bonnet from there Link to comment Share on other sites More sharing options...
Bozz Posted February 28, 2006 Author Share Posted February 28, 2006 Lucky boy (in more ways than one) Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
old captain slow Posted March 1, 2006 Share Posted March 1, 2006 If you ditch the old exhaust and fit the long primaries you will notice an even bigger improvement. Very dangerous going to Dave. Checkbookitis hits very badly. 😬 C7 CDW Link to comment Share on other sites More sharing options...
Bozz Posted March 1, 2006 Author Share Posted March 1, 2006 'Tis in the plans if not the budget yet Be intersted to know anyone's thoughts on sticking IACV though Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Peter Carmichael Posted March 1, 2006 Share Posted March 1, 2006 The retiming of the cams makes the idle settings much more sensitive and a properly working IACV can still result in a fluctuating idle. The remedy seems to be to put a restrictor in the IACV pipe and allow slightly more air through on the throttle stop. A restrictor can be made from a piece of nylon bar with a 3mm hole drilled through the middle and inserted in the tube from the throttle body to the IACV. This can result in a very steady idle. Link to comment Share on other sites More sharing options...
old captain slow Posted March 1, 2006 Share Posted March 1, 2006 Peter, would that solve the problem of a complete dead spot just off tickover. The throttle on mine has always not permitted operation between tickover and about 2000rpm (no load operation - it's fine pulling below that with load on as the throttle is open further). It seems to point to a throttle pot issue, but the pot checks out ok. C7 CDW Link to comment Share on other sites More sharing options...
Bozz Posted March 1, 2006 Author Share Posted March 1, 2006 Ok thanks guys but......... if I wanted to check out the IACV with the manifold in place what is the best way of removing it without losing any bits in the manifold (if this is possible) 🤔 Do you just undo the two torx screws which fit the 'motor' to the valve body or do you undo the 4 torx screws that fix the valve and motor assembly to the manifold? Is it possible that a good clean and relub will reduce any likelihood of sticking? Bozz Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Bozz Posted March 2, 2006 Author Share Posted March 2, 2006 BTTT Sorry, but my karma just ran over your dogma My Chocolate Orange here Link to comment Share on other sites More sharing options...
Peter Carmichael Posted March 2, 2006 Share Posted March 2, 2006 Is it possible that a good clean and relub will reduce any likelihood of sticking Chances are that most instances reported as "sticking" are misattributed. I think you're barking up the wrong tree. Link to comment Share on other sites More sharing options...
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