Guest GTZX Posted September 10, 2008 Share Posted September 10, 2008 Hello. I've tried looking the forum search around and haven't had too much luck. My problem is that I overheated one day due to a coolant hose bursting as I was driving and wasn't realizing my heat gauge went to H till I came to stop and saw the coolant burning off (evaporating) Now that I've got the car operable (oil change, rad flush... needed badly lol and pcvv changed) and went to crank the car I noticed that my idle now is low. . . 500rpms. Avg was arond 800-850 for me before. Until the car actually warms up to normal temperature pumping the brake will cause vacuum pressure loss in the car and it even killed it on my first three pumps. Is this likely my intake/exhaust manifold gasket leaking because the engine got super hot? I think I'm hearing a sucking noise from that "area" where the gasket joins but I can't be certain and don't want to go taking these manifolds off and there's so many rubber hoses and this car was butchered before I got to it, so some of the evap/emissions is not correctly hooked up. Any way I can test if maybe a hose line is causing this leak or a way I can pinpoint it to the manifold itself? I knew i had some small leaks when i bought the car but it never idled bad or shut off when cold by pumping brakes. After it's warmed up pumping the brake does not cause a vacuum issue or engine stutter, but still idles at 490-500rpms and you can WOT it w/o any engine gag (stutter) excepts it drops so low to 500. . . . Also, on atlanticz.ca they show you can adjust the AFM w/ a Idle Flow Control screw on the side . . . mine does not have this? is this specific differnece from Z to ZX?? Quote Link to comment Share on other sites More sharing options...
Guest GTZX Posted September 10, 2008 Share Posted September 10, 2008 I found the answer, car fiche rocks . . . idle is back to normal now. how can i delete this post. . . . Quote Link to comment Share on other sites More sharing options...
woldson Posted September 10, 2008 Share Posted September 10, 2008 I found the answer, car fiche rocks . . . idle is back to normal now. how can i delete this post. . . . Can you give us a heads up? Your post was good, and without a finish, possibly no one will find it in HybredZ's extensive data base. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted September 10, 2008 Share Posted September 10, 2008 yeh i would like to see the conclusion!! Quote Link to comment Share on other sites More sharing options...
Guest GTZX Posted September 11, 2008 Share Posted September 11, 2008 it seems the gasket at the down pipe from the exhaust had blown into peices, that's the sucking noise I'm sure; like, i can just look at it and see it in chunks trying to escape the pipe connection. I think there may be a leak on my valve cover gasket, it looks improperly set in the car and that thing was scalding hot on top when i stopped the car. . . but i checked my oil after running it a few minutes to see if my car had foamy/milky oil {which would tell me if my cyl head gasket had busted} and it looked like brand new oil mixed with that stuff that never comes out unless you drop the pan lol the idle problem was solved by finally finding out where the idle control valve was, and i just unscrewed (to open) till got 750rpms after warming up to average operating temps. The car sounded the healthiest (it purred again ) at 750. my AFM did not have one directly on it as on the photo on atlanticz.ca suggests, but there was one located on the intake manifold about halfway across the back side of the manifold (facing the tire... side of car the actual physical back of the manifold... not the side in the back of the engine compartment.) on the side of it facing the quarter panel & the screw is facing upwards... big flatheaded easy access... i was when i first noticed on the car-fiche, because my 82 one I have does not show it, so I was flabbergasted to see where and how easy it was to spot it but by looking at it I can't say i had ever noticed it as a possibility not used to them not being on the TB itself or the MAF/AFMs . . . still not sure why the idle had got so low, but it runs smooth again minus the leaky gasket issue that is still at large & the butchered setup from the previous owner disconnecting random evap stuff, so i'll have to figure out what goes where! I think somehow my AFM must have been told by the ECU after becoming so overheated that ti adjusted the idle within the afm, and rather then tinker w/ that and break it ([bad luck kinda guy] $80 for a new 1? crap...) http://www.xenonzcar.com has a cool carfiche for S30 S130 to z31/32/33 informative! Quote Link to comment Share on other sites More sharing options...
woldson Posted September 11, 2008 Share Posted September 11, 2008 Great to hear you have it running so well now:) Considering you had to let more air into the engine, have you looked for a vacuume leak? Quote Link to comment Share on other sites More sharing options...
Guest GTZX Posted September 11, 2008 Share Posted September 11, 2008 im in the process of doing that now, actually by this weekend i should have everything mapped out... !!!!!!!!!! Quote Link to comment Share on other sites More sharing options...
Guest michanic220 Posted September 12, 2008 Share Posted September 12, 2008 just be carful with over heating the engine.. aluminum heads and intakes dont like heat.. they tend to warp. then you have to buy new ones. glad you found the problem. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.