stiv2k Posted November 13, 2006 Report Share Posted November 13, 2006 OK so i've been annoyed by this for some time now. I think I have an air leak somewhere I have a hunch its the intake gaskets but i'm not sure. When I start it up cold in the morning it idles high (1500+ RPM) for about 5 minutes or so until it warms up. Also, it idles rough sometimes, even when it's warm. Today I hooked up a vac. meter to 2 different places. Video 1 is hooked up to the brake booster line coming directly out of the plenum, note the vac readings. Video 2 is hooked up to the small line that goes into the cruise control module. I think it goes down to the check valve and the vac. canister ball at the bottom. This is on a 1992 3.1 engine http://steve.neoturbine.net/files/100_2475.MOV http://steve.neoturbine.net/files/100_2476.MOV Sorry if it takes a long time to D/L, but please try and help me figure out if this is something I should be worried about or not, thanks EDIT, in the first video, when you see the level drop to 10 and back suddenly, that's when I'm giving the engine gas. Quote Link to comment Share on other sites More sharing options...
slick Posted November 13, 2006 Report Share Posted November 13, 2006 Didn't watch the video's, but a good way to test your intake gaskets or vacuum leak is to spray some throttle body or carb cleaner where the manifold meets the heads, and spray them onto your vacuum lines as well. If you hear any sort of studder or rpm change(should be fairly noticeable), then there's your culprit Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted November 13, 2006 Report Share Posted November 13, 2006 Downloading now. I'll get back with ya in about 15min. Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted November 13, 2006 Report Share Posted November 13, 2006 Alright, so when hooked to the booster, you got 18 in Hg and hooked to the cruise line you had 20-21 in Hg. Those seem like pretty normal numbers. In the first video before you hit the throttle it knida bounces around but still in the upper teens to 20s. Do what Chris suggested though with the carb cleaner. Quote Link to comment Share on other sites More sharing options...
stiv2k Posted November 13, 2006 Author Report Share Posted November 13, 2006 When i revved it in the 2nd vid, the vac level didn't really change at all, it just sorta slowly went higher...that's normal? when the vac. level sometimes drops to 10 or lower (first vid, hooked to brake booster), i can hear/feel the engine hesitating and it has stalled on occasion in the past Quote Link to comment Share on other sites More sharing options...
Robby1870 Posted November 13, 2006 Report Share Posted November 13, 2006 When i revved it in the 2nd vid, the vac level didn't really change at all, it just sorta slowly went higher...that's normal? when the vac. level sometimes drops to 10 or lower (first vid, hooked to brake booster), i can hear/feel the engine hesitating and it has stalled on occasion in the past I didnt know you gave it gas in the 2nd video. Yeah, it shouldn't go up if you hit the throttle. Quote Link to comment Share on other sites More sharing options...
stiv2k Posted November 14, 2006 Author Report Share Posted November 14, 2006 so i am still unsure if it's the intake gaskets or not...what do ya think? I've never dealt with this before... Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted November 14, 2006 Report Share Posted November 14, 2006 a good way to test your intake gaskets or vacuum leak is to spray some throttle body or carb cleaner where the manifold meets the heads, and spray them onto your vacuum lines as well. If you hear any sort of studder or rpm change(should be fairly noticeable), then there's your culprit Did you try this? Quote Link to comment Share on other sites More sharing options...
stiv2k Posted November 14, 2006 Author Report Share Posted November 14, 2006 ah right i forgot to mention that. I tried it once but a. i couldn't get all the way around the gasket, especially on the right side of the motor there was all this other stuff in the way and b. i couldn't reach the lower intake gasket at all. Maybe i didn't do it right but i did not seem to notice a difference Quote Link to comment Share on other sites More sharing options...
GIANT MOTH Posted November 14, 2006 Report Share Posted November 14, 2006 How can this be a vacuum leak if it runs normal after the engine warms up? I'm an idiot. I'm not a certified mechanic but I'll say . . . . I'm going to guess on checking your EGR Valve, Solenoid, and Throttle Position Sensor. But on the other side of the coin there's the idle relearn. Have you left your battery off the hook? Quote Link to comment Share on other sites More sharing options...
stiv2k Posted November 14, 2006 Author Report Share Posted November 14, 2006 I've done idle relearn a couple of times...EGR i checked about a year ago and seemed to be working fine i haven't looked at it since then though and i haven't unhooked the battery in a very long time...how is that a factor in idle? oh also I never looked at the TPS, is there anything specific i should look for when inspecting it? Quote Link to comment Share on other sites More sharing options...
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