Jellybean Posted March 26, 2016 Share Posted March 26, 2016 How does a higher cam duration (i.e.264) affect Vacuum and Idle? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 27, 2016 Share Posted March 27, 2016 That's still quite a tame profile, but it will slightly reduce vacuum and slightly destabilise the idle. There's more to it on a twin cam engine, as the ability to alter the phasing of the two cams timing relative to one another will also affect idle and vacuum. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted March 27, 2016 Author Share Posted March 27, 2016 Thanks Chris I have the Tomei 264 cams in with the Stock ECU (Sard Rom in it) , on cold starts I need to keep my foot on the accelerator to stop her cutting out until it warms up and even then she can fluctuate between 1 and 0 rpm I was just wondering the principle behind what is causing it , Tomei Claim stable idle in stock ECU Quote Link to comment Share on other sites More sharing options...
bignum Posted March 27, 2016 Share Posted March 27, 2016 I just fitted 264 cams, idle was affected massively, overfueling in the 10-11 range until the remap was done. Do you have afr gauge jelly? Quote Link to comment Share on other sites More sharing options...
Jellybean Posted March 27, 2016 Author Share Posted March 27, 2016 Same here dude , over fuels till warmed up I don't have an AFR gauge but once she is at a temp of about 30 degrees , she runs fine and goes like an antichrist Garage said they checked AFRs Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 28, 2016 Share Posted March 28, 2016 I just fitted 264 cams, idle was affected massively, overfueling in the 10-11 range until the remap was done. Do you have afr gauge jelly? You, my friend, have just solved my long term headache. Quote Link to comment Share on other sites More sharing options...
bignum Posted March 28, 2016 Share Posted March 28, 2016 You, my friend, have just solved my long term headache. Good to know, whats happening with yours?, i was kind of stumped when i had the issue as i`d rebuilt the engine aswell and thought i`d missed something, but then found some info on the net and confirmed with my mapper it could be cams, it was tweaked on the map within 5 mins. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted March 28, 2016 Author Share Posted March 28, 2016 Its just on closed loop , needs fuel pulled till ECU goes to Open loop ; I was even contemplating a resistor and switch toggle to the TPS to get her idling on closed loop then once she goes to open loop , toggle the switch off I think HKS IS Fcon might be the most cost effective ECU solution plus no splicing into the harness , just PNP Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 28, 2016 Share Posted March 28, 2016 Good to know, whats happening with yours?, i was kind of stumped when i had the issue as i`d rebuilt the engine aswell and thought i`d missed something, but then found some info on the net and confirmed with my mapper it could be cams, it was tweaked on the map within 5 mins. Exactly the same as yours mate, running really rich on idle, pretty much exactly the same AFRs too. Ive changed just about every sensor and was about to tear it all down to see if Id missed something. Quote Link to comment Share on other sites More sharing options...
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