Need some help, surging idle. Logs included!
Good evening all!! I've been lurking a while and have used the site as an aid for some of my tuning and setup problems. Ive finally got to the point of logging and getting my idle right. So here is a log of the problem I am having. 1955 Chevy Bel Air 355sbc 440hp Fitech 600PA. The idle surges a lot, please hopefully someone can advise.
Was this log recorded when engine was at temperature. If so, you have an issue with your CTS. Replace with part listed on the Parts and Accessories topic.
no it was not up to temp but I took another log once it was up to temp at the end. then when I hit the throttle it lean popped and died. that is at the end of the first log. the second log was taken just 10 min or less after the pop and die, but it was idling great and barely surging at all.
https://www.dropbox.com/s/3b86myx7njtl1vs/DashBoard18.csv?dl=0
https://www.dropbox.com/s/88dwev34pw2q3n1/DashBoard19.csv?dl=0
That last log is looking fairly good. I really need to see a 30 second idle log at 195 or whatever your thermostat is. Until we get the idle correct, we cannot tune anything else.
ok so I know it has been a few days but I got busy at home and the shop and just had time to do a full warm up and log. Sorry it is such a long log. I had a shorter demo log but I forgot to end it before disconnecting just now. I hope this can help. It seems to be idling better but now my question is how to get rid of the long hang it has coming down from reving. Thank you again for all the experience and help.
https://www.dropbox.com/s/vyw8y2z1zym1hcf/DashBoard24.csv?dl=0
Also even though my idle is better it never really evens out or is that just the lag in the ecu making it look that way? I would also like to lean out more at idle but when I go leaner than 14.10 I get a bad lean pop on fast acceleration
Tell me about your engine and Fitech settings. Cam specs specifically
Motor is a forged 355, 10:1ish compression hogged out hump heads, comp cams cam card included below. As far as fitech settings they are mostly factory.
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What is your cam setting, idle setting?