# Engine/power screwed up **URL:** \ **Category:** SON240sx Automotive\ **Created:** [July 31, 2009, 1:33pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776 "2009-07-31T13:33:37Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![240xcsv](https://avatars.discourse-cdn.com/v4/letter/2/bbe5ce/32.png) [@240xcsv](https://forums.speedlife.net/u/240xcsv)\ **Post date:** [July 31, 2009, 1:33pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/1 "2009-07-31T13:33:37Z")
91 KA DOHC S13 I’ve changed o2 sensor a few months back, new fatter wires, new spark plugs, new coolant temp sensor, new fuel filter. I just changed the maf with one from avery in better shape than my old one. New oil/oil filter a while back, new air filter. I have only throttle position sensor and computer that i havent touched (auto ecu btw). I run 91 all the time and 94 when on track. This problem went away and now came back… it seems like as it gets hotter this comes? Someone lend me a hand here :-/ Since last few days it came again (different now though). Copy pasted from frustration post elsewhere lol: my engine is running like \*\*\*\* … i dont know what it is… before the prob i had we figured out that hitting the maf the car literally started running fine… so we figured maf… i just put a new maf in still acting same way… its running super rich as it backfires for sure from time to time. and… when i give it throttle it hesitates then suddenly goes and sometimes its like there’s nothing happening when u press throttle pedal and then suddenly there is and suddenly it starts slowing down then goes as well its weird Also at a stop light after a nice run… the idle goes way down like 600rpm and it starts jumping up down 100rpm broom broom broom broom broom and wants to shut down lights going out back and forth lol… I want this crap resolved ☹ ---
**Author:** ![ronnie416](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ronnie416/32/5480_2.png) [@ronnie416](https://forums.speedlife.net/u/ronnie416)\ **Post date:** [July 31, 2009, 1:42pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/2 "2009-07-31T13:42:19Z")
> [@Buffalo area snowboarders?](https://forums.speedlife.net/t/buffalo-area-snowboarders/23326/9): > > I have only throttle position sensor and computer that i havent touched (auto ecu btw). > > I run 91 all the time and 94 when on track. > > This problem went away and now came back… it seems like as it gets hotter this comes? > > its running super rich as it backfires for sure from time to time. and… when i give it throttle it hesitates then suddenly goes and sometimes its like there’s nothing happening when u press throttle pedal and then suddenly there is and suddenly it starts slowing down then goes as well its weird > > Also at a stop light after a nice run… the idle goes way down like 600rpm and it starts jumping up down 100rpm broom broom broom broom broom and wants to shut down lights going out back and forth lol… > > I want this crap resolved ☹ Well, if you haven’t changed or touched your TPS, that seems to be your culprit. Also, Why the hell are you running 94 on the track? It’s a stock KA man. ---
**Author:** ![ronnie416](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ronnie416/32/5480_2.png) [@ronnie416](https://forums.speedlife.net/u/ronnie416)\ **Post date:** [July 31, 2009, 1:43pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/3 "2009-07-31T13:43:10Z")
or even 91…why? Yeah, if you wanna troubleshoot your TPS, you can try mine and see if it fixes your problem. ---
**Author:** ![87s15lt1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/87s15lt1/32/5706_2.png) [@87s15lt1](https://forums.speedlife.net/u/87s15lt1)\ **Post date:** [July 31, 2009, 1:54pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/4 "2009-07-31T13:54:33Z")
just put a volt meter on the tps and do a slow sweep and watch for glitches. I don’t think that is the problem either way. ---
**Author:** ![R33](https://avatars.discourse-cdn.com/v4/letter/r/5f8ce5/32.png) [@R33](https://forums.speedlife.net/u/R33)\ **Post date:** [July 31, 2009, 2:06pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/5 "2009-07-31T14:06:44Z")
rotor / cap? try another maf ? The owners manual recommends 91 … , i ran 94 with advanced timing. ---
**Author:** ![240xcsv](https://avatars.discourse-cdn.com/v4/letter/2/bbe5ce/32.png) [@240xcsv](https://forums.speedlife.net/u/240xcsv)\ **Post date:** [July 31, 2009, 2:07pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/6 "2009-07-31T14:07:10Z")
Ya that’s the one thing left :-/… i hope its nothing else urgh… R33: Yeah that’s why I run 91, it even says run premium on the fuel filler cap. I just wana dump the ka and move on but its not gona happen this year… and i dun want an sr either… not that, that’s economical either lol. Rotor cap also changed recently. This is another maf i tried… so what are the odds of both having the same problem :-/ Not like avery would sell me a busted one… It’d be nice if i swing by someone or a shop that knows 240s and figures this simpleton stupidity out for me… ---
**Author:** ![ronnie416](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ronnie416/32/5480_2.png) [@ronnie416](https://forums.speedlife.net/u/ronnie416)\ **Post date:** [July 31, 2009, 2:10pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/7 "2009-07-31T14:10:00Z")
> [@FF or Cheap: Cleaning Garage - Now w/56k Warning!](https://forums.speedlife.net/t/ff-or-cheap-cleaning-garage-now-w-56k-warning/23327/26): > > rotor / cap? try another maf ? > > The owners manual recommends 91 … , i ran 94 with advanced timing. Doesn’t the owners manual recommend 91 RON, whcih is different from 91 MON. his timing is not advanced. It’s pointless to throw money away on a stock motor. ---
**Author:** ![R33](https://avatars.discourse-cdn.com/v4/letter/r/5f8ce5/32.png) [@R33](https://forums.speedlife.net/u/R33)\ **Post date:** [July 31, 2009, 2:18pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/8 "2009-07-31T14:18:55Z")
swap mafs with a running 240’s maf … and see if that makes any improvement - shouldnt take more than few mins. That way you will know for sure if the maf is the culprit ---
**Author:** ![bmart](https://avatars.discourse-cdn.com/v4/letter/b/9d8465/32.png) [@bmart](https://forums.speedlife.net/u/bmart)\ **Post date:** [July 31, 2009, 2:24pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/9 "2009-07-31T14:24:37Z")
coolant sensor? ---
**Author:** ![240xcsv](https://avatars.discourse-cdn.com/v4/letter/2/bbe5ce/32.png) [@240xcsv](https://forums.speedlife.net/u/240xcsv)\ **Post date:** [July 31, 2009, 2:27pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/10 "2009-07-31T14:27:53Z")
i just swapped the maf… coolant sensor was changed… only thing left is tps really :-/ … dont know what else to look for… I guess ronnie we can do something… im working literally until 3am today… so maybe tomorrow morning… i wish and hope this could be resolved tomorrow so that i can go dunnville for some fun and not live with just another hassle on our broke ass 20 year old cars hah… ---
**Author:** ![twistedj89](https://avatars.discourse-cdn.com/v4/letter/t/b5ac83/32.png) [@twistedj89](https://forums.speedlife.net/u/twistedj89)\ **Post date:** [July 31, 2009, 2:56pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/11 "2009-07-31T14:56:06Z")
take a close look at the electrical wires sounds like u might have a broken wire or even loose contacts at maf or one the other sensors. ---
**Author:** ![240xcsv](https://avatars.discourse-cdn.com/v4/letter/2/bbe5ce/32.png) [@240xcsv](https://forums.speedlife.net/u/240xcsv)\ **Post date:** [July 31, 2009, 6:53pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/12 "2009-07-31T18:53:12Z")
You know someone suggested to run an extra ground… I am not sure from where to where… anyone done this? This could aleviate some issues no doubt anyways? Someone got a pic of this sort of marvel? Ronnie respond I want zee tps sir. ---
**Author:** ![ronnie416](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ronnie416/32/5480_2.png) [@ronnie416](https://forums.speedlife.net/u/ronnie416)\ **Post date:** [July 31, 2009, 7:03pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/13 "2009-07-31T19:03:18Z")
you can come over anytime you want. swap TPS’s and try em and then swap em back. 🙂 text me. check my FS posts. ---
**Author:** ![BRA\_GANZAAAAAA](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bra_ganzaaaaaa/32/5673_2.png) [@BRA\_GANZAAAAAA](https://forums.speedlife.net/u/BRA_GANZAAAAAA)\ **Post date:** [July 31, 2009, 7:46pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/14 "2009-07-31T19:46:32Z")
vacum leak ---
**Author:** ![simplemind7](https://avatars.discourse-cdn.com/v4/letter/s/0ea827/32.png) [@simplemind7](https://forums.speedlife.net/u/simplemind7)\ **Post date:** [July 31, 2009, 8:28pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/15 "2009-07-31T20:28:24Z")
Sounds like TPS to me. Test or swap it. ---
**Author:** ![kimmerkaze](https://avatars.discourse-cdn.com/v4/letter/k/9d8465/32.png) [@kimmerkaze](https://forums.speedlife.net/u/kimmerkaze)\ **Post date:** [July 31, 2009, 11:48pm UTC](https://forums.speedlife.net/t/engine-power-screwed-up/126776/16 "2009-07-31T23:48:11Z")
why don’t you just check your full close voltage and WOT voltage for the tps? then evaluate what kind of range you’re getting from full close to open, refer to specs, adjust if necessary, and then decide on whether or not it’s worth your time to get another tps? it takes literally 1 min to check your tps voltage range…not sure why you haven’t done this already before looking into getting another tps. btw, throw some 87 reg gas in and try that out. like ronnie said i don’t know why you’d run 91 or 94 on a stock ka…even if the manual ‘recommends’ 91.