# Need help with sr20det please!? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** nissan, 240sx\ **Created:** [April 18, 2011, 9:42pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841 "2011-04-18T21:42:52Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 18, 2011, 9:42pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/1 "2011-04-18T21:42:52Z")
i have a 96 240 w/ sr20det 5 spd. problem comes and goes. when at a stop in neutral ides between 1300 rpm down to 0 and almost stalling, then when i take off ( and in any gear) there is noticeable lag and engine wont rev past 5200 rpm like there is a rev limiter or governor. then the problem will just go away for a while. i’ve only tried cleaning the IAC valve ---
**Author:** ![FoDaddy](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/fodaddy/32/717_2.png) [@FoDaddy](https://community.cartalk.com/u/FoDaddy)\ **Post date:** [April 18, 2011, 11:09pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/2 "2011-04-18T23:09:14Z")
You didn’t try to reuse the ECU from the stock KA24 did you? It sounds like the ECU doesn’t have proper tune, when it’s running it’s not running really rich is it? ---
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 19, 2011, 1:33am UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/3 "2011-04-19T01:33:13Z")
the ecu is sr. it runs perfectly when this problem isn’t occurring. when the problem does occur it runs really rich when im idling when its doing the fluctuating rpm thing ---
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 19, 2011, 1:35am UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/4 "2011-04-19T01:35:42Z")
could i rule out the maf or iac? if the maf or iac were broken wouldn’t the engine always run poorly? ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [April 19, 2011, 3:27am UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/5 "2011-04-19T03:27:12Z")
Are there any conditions that reliably trigger the problem? As an example, I had a CRX with a swapped intake manifold (swap done by the previous owner) that would do pretty much what your car does, every single time I floored it. After poking around, I found a detached vac line. It’s run fine ever since. ---
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 19, 2011, 5:37am UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/6 "2011-04-19T05:37:46Z")
no there is nothing that sets off the problem that i have noticed( and i pay pretty close attention). and the problem will NOT show up for weeks or months and then show up and seem to last for a day or two. and im just asking because i don’t know, but wouldn’t a detached vac line continuously cause problems? like i said, my particular problem will go away and the car runs like a champ. ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [April 19, 2011, 3:46pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/7 "2011-04-19T15:46:34Z")
Depends on where the vac line is - it might require certain conditions, like a WOT run to redline, to trigger it. Are there any stored codes in the ECU? Do you perhaps have a bad wire somewhere that from time to time could contact a ground? Other than that, is it possible you’re getting bad gas? ---
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 19, 2011, 5:16pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/8 "2011-04-19T17:16:02Z")
i can floor the car and have nothing unusual happen time after time. and im very cautious about what gas i use. what kind of stored codes? btw i did not do the swap so some things i may not be able to answer ---
**Author:** ![shadowfax](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/shadowfax/32/13026_2.png) [@shadowfax](https://community.cartalk.com/u/shadowfax)\ **Post date:** [April 19, 2011, 5:18pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/9 "2011-04-19T17:18:40Z")
The flooring the car was just an example. As for what kind of stored codes - codes stored by the ECU that might indicate a fault. Does your check engine light come on when it runs poorly? ---
**Author:** ![sleeperx](https://avatars.discourse-cdn.com/v4/letter/s/5e9695/32.png) [@sleeperx](https://community.cartalk.com/u/sleeperx)\ **Post date:** [April 19, 2011, 5:26pm UTC](https://community.cartalk.com/t/need-help-with-sr20det-please/63841/10 "2011-04-19T17:26:28Z")
no it never throws a code unfortunately