# Help please! Rpms fall and engine turns off **URL:** \ **Category:** SON240sx Automotive\ **Created:** [October 24, 2008, 3:31pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417 "2008-10-24T15:31:13Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![STREET-ANGEL](https://avatars.discourse-cdn.com/v4/letter/s/db5fbb/32.png) [@STREET-ANGEL](https://forums.speedlife.net/u/STREET-ANGEL)\ **Post date:** [October 24, 2008, 3:31pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/1 "2008-10-24T15:31:13Z")
i’ve searched and searched, and couldn’t really find a solution. I’ve had my SR20 for about week now and. it was pretty good, until I went to drive it, and when I go above 30mph, and put it in neutral to slow down, the rpms fall to zero and the engine dies! Can someone please help me out? thanks ---
**Author:** ![Tacoboy](https://avatars.discourse-cdn.com/v4/letter/t/2acd7d/32.png) [@Tacoboy](https://forums.speedlife.net/u/Tacoboy)\ **Post date:** [October 24, 2008, 3:33pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/2 "2008-10-24T15:33:16Z")
vacuum leak. ---
**Author:** ![STREET-ANGEL](https://avatars.discourse-cdn.com/v4/letter/s/db5fbb/32.png) [@STREET-ANGEL](https://forums.speedlife.net/u/STREET-ANGEL)\ **Post date:** [October 24, 2008, 3:41pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/3 "2008-10-24T15:41:48Z")
the bov is loose it moves around could that be it? ---
**Author:** ![Specialedition](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/specialedition/32/5714_2.png) [@Specialedition](https://forums.speedlife.net/u/Specialedition)\ **Post date:** [October 24, 2008, 3:43pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/4 "2008-10-24T15:43:33Z")
do a leak down test, tighten up your BOV and see if it helps ---
**Author:** ![STREET-ANGEL](https://avatars.discourse-cdn.com/v4/letter/s/db5fbb/32.png) [@STREET-ANGEL](https://forums.speedlife.net/u/STREET-ANGEL)\ **Post date:** [October 24, 2008, 3:44pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/5 "2008-10-24T15:44:35Z")
im gona go try that thanks guys ---
**Author:** ![kennyeros](https://avatars.discourse-cdn.com/v4/letter/k/49beb7/32.png) [@kennyeros](https://forums.speedlife.net/u/kennyeros)\ **Post date:** [October 24, 2008, 4:23pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/6 "2008-10-24T16:23:13Z")
my friend has a 240 with sr and all 3 inch piping and a greddy type s blow off vavle , if u down shift it wont do it , and if u put it in neutral it will just drop rpms and sometiems stall out , just downshift and ull be ok 🙂 or just give a lil gas when its in neutral 🙂 ---
**Author:** ![STREET-ANGEL](https://avatars.discourse-cdn.com/v4/letter/s/db5fbb/32.png) [@STREET-ANGEL](https://forums.speedlife.net/u/STREET-ANGEL)\ **Post date:** [October 24, 2008, 4:32pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/7 "2008-10-24T16:32:15Z")
thats what im doing right now, lol but i need to know exacly whats rong with it, it needs to be fixed ---
**Author:** ![polishprince](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/polishprince/32/5690_2.png) [@polishprince](https://forums.speedlife.net/u/polishprince)\ **Post date:** [October 24, 2008, 7:17pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/8 "2008-10-24T19:17:10Z")
i had this problem too… i tightened all hoses, cleaned maf and cas first with electrical cleaner… seemed to get better… then i clean iacv sensor through the idle screw then i cleaned my throttle body today… so much black crap… used a toothbrush too… does not drop idle when i clutch in anymore so i would do that if nothing else works ---
**Author:** ![Gongster](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gongster/32/5615_2.png) [@Gongster](https://forums.speedlife.net/u/Gongster)\ **Post date:** [October 25, 2008, 3:42pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/9 "2008-10-25T15:42:10Z")
If your BOV is atmospheric it will cause your car to cut off when you clutch in or put it in neutral. If that is whats causing the problem either recirculate your BOV or run the MAFS in a blow through setup. ---
**Author:** ![Jlevesque3](https://avatars.discourse-cdn.com/v4/letter/j/edb3f5/32.png) [@Jlevesque3](https://forums.speedlife.net/u/Jlevesque3)\ **Post date:** [November 12, 2008, 3:41pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/10 "2008-11-12T15:41:20Z")
how do you run in a blow thro setup? ---
**Author:** ![Jlevesque3](https://avatars.discourse-cdn.com/v4/letter/j/edb3f5/32.png) [@Jlevesque3](https://forums.speedlife.net/u/Jlevesque3)\ **Post date:** [November 12, 2008, 3:41pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/11 "2008-11-12T15:41:50Z")
im havin same problem, its a ka-t with a greddy type s ---
**Author:** ![Sky14](https://avatars.discourse-cdn.com/v4/letter/s/bcef8e/32.png) [@Sky14](https://forums.speedlife.net/u/Sky14)\ **Post date:** [November 12, 2008, 4:05pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/12 "2008-11-12T16:05:29Z")
if its none of hte above problems jsut get the hks idlestabilizer ---
**Author:** ![Martino](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/martino/32/5674_2.png) [@Martino](https://forums.speedlife.net/u/Martino)\ **Post date:** [November 12, 2008, 4:13pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/13 "2008-11-12T16:13:05Z")
If your running a blow off valve without any sort of recirculation, this is whats going to happen. ---
**Author:** ![ka2.4et](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ka2.4et/32/5727_2.png) [@ka2.4et](https://forums.speedlife.net/u/ka2.4et)\ **Post date:** [November 12, 2008, 4:41pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/14 "2008-11-12T16:41:59Z")
fuel is a problem, a vacuum leak or boost leak will not cause the car to stall, it would run rough during idle your leaning out during deceleration, what setup do you have running? this could also be the problem of a open atmospheric bov, the engine cannot compensate for the dramatic lose of air, and the maf will mis calculate voltage load on the hot wire ---
**Author:** ![Tacoboy](https://avatars.discourse-cdn.com/v4/letter/t/2acd7d/32.png) [@Tacoboy](https://forums.speedlife.net/u/Tacoboy)\ **Post date:** [November 12, 2008, 5:17pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/15 "2008-11-12T17:17:11Z")
> [@Your home theatre/stereo set up, Moffitt need not apply](https://forums.speedlife.net/t/your-home-theatre-stereo-set-up-moffitt-need-not-apply/19066/2): > > fuel is a problem, a vacuum leak or boost leak will not cause the car to stall, it would run rough during idle your leaning out during deceleration, what setup do you have running? this could also be the problem of a open atmospheric bov, the engine cannot compensate for the dramatic lose of air, and the maf will mis calculate voltage load on the hot wire dude, are you kidding? a vac leak will CERTAINLY cause a car to stall. ---
**Author:** ![Martino](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/martino/32/5674_2.png) [@Martino](https://forums.speedlife.net/u/Martino)\ **Post date:** [November 12, 2008, 5:29pm UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/16 "2008-11-12T17:29:48Z")
Lol, i can defiantly vouch for a vacuum leak causing the car to die. Even a bov that leaks is a vacuum leak, and will cause the car to die. Especially when off throttle. ---
**Author:** ![ka2.4et](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ka2.4et/32/5727_2.png) [@ka2.4et](https://forums.speedlife.net/u/ka2.4et)\ **Post date:** [November 14, 2008, 10:27am UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/17 "2008-11-14T10:27:10Z")
no it wont, the only vacuum leak possible to cause a car to actually die one be the main to the brake booster, no car would die or stall from a leaking vacuum line, the idle would be high or even eratic and jump from 500 to 1500 but it should never die, the only reason that happens is because the hot wire maf will be miscalculated, but and more fuel would be consumed to compensate ---
**Author:** ![ka2.4et](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ka2.4et/32/5727_2.png) [@ka2.4et](https://forums.speedlife.net/u/ka2.4et)\ **Post date:** [November 14, 2008, 10:34am UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/18 "2008-11-14T10:34:55Z")
please explain your theory of a vacuum line stalling a car, sorry if there are multiple leaks then yes, but a single line or even 2 should not cause a car to stall, possibly dirty hot wire ---
**Author:** ![ka2.4et](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ka2.4et/32/5727_2.png) [@ka2.4et](https://forums.speedlife.net/u/ka2.4et)\ **Post date:** [November 14, 2008, 10:38am UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/19 "2008-11-14T10:38:46Z")
and anything before the maf like the bov is not a vacuum leak, it is a boost, leak but i guess this depends on were you maf is located, which should be for the most accurate reading right before the throttle body, you want the air measured right before it enters the engine, after the intercooler because cold air is more dense, i see people have it near the turbo and that air is hot so the maf will calculate fuel for hot air not cold, which means you’ll be running rich, also there is manifold vacuum and ported vacuum, before and after throttle body ---
**Author:** ![ka2.4et](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ka2.4et/32/5727_2.png) [@ka2.4et](https://forums.speedlife.net/u/ka2.4et)\ **Post date:** [November 14, 2008, 10:42am UTC](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417/20 "2008-11-14T10:42:52Z")
sorry it will run lean [Next page](https://forums.speedlife.net/t/help-please-rpms-fall-and-engine-turns-off/119417.md?page=2)