# Missfire problem **URL:** \ **Category:** SON240sx Automotive\ **Created:** [November 9, 2008, 3:01pm UTC](https://forums.speedlife.net/t/missfire-problem/119751 "2008-11-09T15:01:55Z")\ **Posts on this page:** 20\ **Page:** 1
**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:** [November 9, 2008, 3:01pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/1 "2008-11-09T15:01:55Z")
This is a continuation from my other thread, Ok so i just installed my splitfire coils and the car now runs. Problem is im still missfiring in Cyl #4. So right now the engine is knocking. Ive ruled out these possible problems -Coils -plugs Now i might think its the injectors and one is just staying open. Any suggestions of what i can do would be gravy right now Thanks ---
**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:** [November 9, 2008, 3:29pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/2 "2008-11-09T15:29:45Z")
un-plug injector. see if any difference occurs. then go from there don;t leave it un-plugged for to long. no spark = okay no fuel = kaboom hypothetically speaking of course ---
**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 9, 2008, 3:39pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/3 "2008-11-09T15:39:30Z")
Missfire is normally caused by coils or plugs. Make sure your plugs are gapped properly. Try changing heat range, and try getting some OEM sr coils that you know work. Reason I say this, is because splitfire coils are known to sometimes cause more issues than solve one. Try that and see how it goes. ---
**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:** [November 9, 2008, 10:27pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/4 "2008-11-09T22:27:06Z")
what would unplugging a injector do? only thing i can think of is lean out the cylinder to see if the injector is over flowing. I guess ill try this to see if it makes a difference. i hope this is what it is ---
**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:** [November 10, 2008, 8:31am UTC](https://forums.speedlife.net/t/missfire-problem/119751/5 "2008-11-10T08:31:27Z")
ok so i unplugged my injectors, and yes when i unplugged number 4 nothing happened the rest there was a dramatic difference. I also went to a garage and he told me it could have been my ecu when the original detonation accured. I dont know if i should spend more money on a maybe issue or just get the motor swapped? ---
**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:** [November 10, 2008, 8:51am UTC](https://forums.speedlife.net/t/missfire-problem/119751/6 "2008-11-10T08:51:59Z")
compression test. get ALL the injectors flow tested. leak down test. be sure you have spark. ---
**Author:** ![bmart](https://avatars.discourse-cdn.com/v4/letter/b/9d8465/32.png) [@bmart](https://forums.speedlife.net/u/bmart)\ **Post date:** [November 10, 2008, 8:53am UTC](https://forums.speedlife.net/t/missfire-problem/119751/7 "2008-11-10T08:53:57Z")
check your injector o-ring. My brothers Supra was missfiring because of a missing o-ring between an injector and the manifold. ---
**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:** [November 10, 2008, 8:55am UTC](https://forums.speedlife.net/t/missfire-problem/119751/8 "2008-11-10T08:55:27Z")
^^^ which would create a vacuum leak which = high idle ---
**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:** [November 10, 2008, 9:30am UTC](https://forums.speedlife.net/t/missfire-problem/119751/9 "2008-11-10T09:30:41Z")
my idle is still at 700rpm. Does anyone live in the montreal region so i can test my ecu and see if thats the 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:** [November 10, 2008, 2:17pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/10 "2008-11-10T14:17:41Z")
honestly i don’t think it would be you ecm. just my opinion ---
**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:** [November 10, 2008, 2:52pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/11 "2008-11-10T14:52:24Z")
i dont knwo its wierd. Because when this problem originated what happened was i was driving in third going on the highway and i pretty much went up to 6000rpm and massive missfire happened and then after that my car was limping so maybe it sent a surge to my ecu and blew a resistor. This happened to my buddy in his gtr so maybe its possible it happened to me. Unfortunitely to find out i need to buy new injectors ---
**Author:** ![slipperysilvia](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/slipperysilvia/32/5485_2.png) [@slipperysilvia](https://forums.speedlife.net/u/slipperysilvia)\ **Post date:** [November 10, 2008, 2:53pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/12 "2008-11-10T14:53:57Z")
injectors for stock srs are cheap… i woudl check gaskets all around your turbo and exhaust manifold area also… ---
**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:** [November 10, 2008, 4:36pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/13 "2008-11-10T16:36:08Z")
> [@I hate sisters....](https://forums.speedlife.net/t/i-hate-sisters/19030/2): > > injectors for stock srs are cheap… > i woudl check gaskets all around your turbo and exhaust manifold area also… Can you get me some injectors? stock ones ofcoarse ---
**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:** [November 14, 2008, 2:45pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/14 "2008-11-14T14:45:40Z")
alright so i know my problem and its what i feared. I have low compression in cylinder # 4, I plan on doing a swap next week. Other then that what i can cause low compression so maybe its cheaper to fix the problem. ---
**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 14, 2008, 3:31pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/15 "2008-11-14T15:31:25Z")
Wait…so you had missfireing while in boost and you’ve found out you have low compression? Oh god… ---
**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:** [November 14, 2008, 3:43pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/16 "2008-11-14T15:43:25Z")
well i was having missfire under boost then one day the car just started running on 3 cylinders and the # 4 cylinder was knocking so i changed my coils and plugs that did nothing, So i bought another injector thinking that was the problem but i did a compression test and there was no compression what so ever ---
**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 14, 2008, 3:44pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/17 "2008-11-14T15:44:19Z")
ah, i need to do a test…_gulp_ ---
**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:** [November 14, 2008, 3:46pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/18 "2008-11-14T15:46:27Z")
> [@You know what really sucks?](https://forums.speedlife.net/t/you-know-what-really-sucks/19087/6): > > ah, i need to do a test…_gulp_ your having missfire problems? ---
**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 14, 2008, 3:48pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/19 "2008-11-14T15:48:18Z")
yea but at like 5grand…on an rb20…and my symptons all point to coilpacks so im not tooooo worried lol ---
**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:** [November 14, 2008, 3:50pm UTC](https://forums.speedlife.net/t/missfire-problem/119751/20 "2008-11-14T15:50:08Z")
how heavy is your missfire, meaning is it small hesitation or is it serious it shakes the car when it happens? [Next page](https://forums.speedlife.net/t/missfire-problem/119751.md?page=2)