Random idle surge, hangs high and automatic cruize w/90mm lsx 427, help please!
07-31-2004, 10:14 AM
#1
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Random idle surge, hangs high and automatic cruize w/90mm lsx 427, help please! Was hoping someone would share how they have cured this problem. An edit file of someone that has fixed this problem would be great! Made some gain by copying all the idle maps from a zr1 camaro, now it is more random, but there and very annoying to drive. VE table is 75% 400 through 1200, have tried the 400 at 60%, 800 at 80% and 1200 at 90%, symptom appears the same. Has an z1 MTI camshaft 236-585-112. Atleast I could have some things to try if I had someones edit file that has a similar setup. Would very much appreciate the help! 
08-02-2004, 04:10 PM
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I had a similar problem with my head/cam install. It was a vacuum leak. When you install the intake, you need to torque it down in a special sequence in two phases. The first phase is 49 in-lbs (3 ft-lbs). The second phase is 89 in-lbs (5.56 ft-lbs.)
See LS1howto: http://www.ls1howto.com/index.php?ar...7602ae7b3c1fce
Also you need to make sure that the fuel rails are tight on the injectors. After I re-tighten everything the surging disappeared.
Good luck,
Al
See LS1howto: http://www.ls1howto.com/index.php?ar...7602ae7b3c1fce
Also you need to make sure that the fuel rails are tight on the injectors. After I re-tighten everything the surging disappeared.
Good luck,
Al
