phantaz Posted April 6, 2007 Share Posted April 6, 2007 In my 77 When im just revving the motor or just driving around town my RPM hangs around 2500 and slowly idles down ..it pauses at a few points along the way down to 850. for example... sitting in my drive way i can blip it to around 3500 or 4000 quick and let off and it just drop quick right to around 2500..it will pause/ level for about 1/2 a second then slowly comes down to normal idle point. Now when im running it around and playing with it this isnt an issue since my shifts are at a much higher RPM and when upshifting its usually dropped to a point above that really quick. but when just cruising or revving it does this. it sounds like its almost the throttle sticking but its not that.. is this a sign of bad compression?? weird FI thing?? or just the natural point of air and fuel idleing for the the FI? I have played with the AFM for better flow rate and have a slightly hotter cam in it from MSA but no aftermarket FI yet. Quote Link to comment Share on other sites More sharing options...
naviathan Posted April 6, 2007 Share Posted April 6, 2007 Search for BCDD (Boost Controlled Deceleration Device Quote Link to comment Share on other sites More sharing options...
phantaz Posted April 6, 2007 Author Share Posted April 6, 2007 Boost?? whats this here BOost thing eveyone keeps mentioning?? LOL sorry for not mentioning.. its the stock NA motor other than the afore mentioned upgrades.. hell i dont even have headers yet.... im so in the stone age. Quote Link to comment Share on other sites More sharing options...
naviathan Posted April 6, 2007 Share Posted April 6, 2007 No, it has nothing to do with a turbo. Your engine has one trust me. Quote Link to comment Share on other sites More sharing options...
phantaz Posted April 6, 2007 Author Share Posted April 6, 2007 hmmm off the the haynes manual i go. Quote Link to comment Share on other sites More sharing options...
ZDrifter Posted April 6, 2007 Share Posted April 6, 2007 Make sure your air filter is clean as well... Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted April 6, 2007 Share Posted April 6, 2007 Read these two links.... http://www.atlanticz.ca/zclub/techtips/aar/index.html. http://www.atlanticz.ca/zclub/techtips/airleaks/index.html. LARRY Quote Link to comment Share on other sites More sharing options...
JSM Posted April 6, 2007 Share Posted April 6, 2007 Also check for a vacum leak. I'm 99% sure mine has a slow leak in the brake booster. When I step on the brakes at a light the RPM's go up. If i put the emergency brake on and hit the gas real quick it dies down to normal. Give it a shot, it could be your brake booster leaking. Quote Link to comment Share on other sites More sharing options...
phantaz Posted April 6, 2007 Author Share Posted April 6, 2007 The idle isnt running fast as those two articles seem to mention but the idea of airflow confusing the sensors might be the culprit since its rmp on the way down after you blip the throttle... its not realy harming anything just mostly annoying. a few people around the block like the car and love how it sounds at high RPMS but that weird hang up is starting to make me wonder if something else is about explode in my face. =0) Just for clarifacation.. when the car is in neutral or with the clutch in and parkingbrake set.. if you blip the throttle it hangs up around 2500rpm on the way back down .... that one of the reason i thought it might be bad compression... no compression means no force on the revs to idle it down.. it does idle down it just pauses at a few place but most noticable at 2500 rpm. Quote Link to comment Share on other sites More sharing options...
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