Engine statered bucking yesterday, suggestions?
02-20-2008, 02:46 PM
#1
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Scikotics
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Engine statered bucking yesterday, suggestions?
I have an 06 xB with 20k miles on it. Exhaust has an Apexi Active Tail Silencer.
Yesterday I'm coming back from lunch (engine warmed up) and the engine starts bucking hard, sputtering and seems like it's about to die. letting ll the way off the gas stopped it, but pressing the accelerator would cause it to hiccup again. Made it back to work by cruising without really pressing the gas pedal. It did not happen that morning, going to lunch, or on the way home at the end of the day. I had also filled up a few days before at WaWa, I run 91 octane.
Sometimes at stop lights it bogs down for a second or two as well, Any ideas what happened yesterday; should I chock this up to an injector clog and jsut throw in some STP? I'll be pulling the plugs to check them for deposits. I pulled the silencer off to hopefully blow out any buildup in the exhaust system.
I've had one previous issues with the car:
1) Engine would cut out and stay dead randomly (at lights, when cruising, any time)
Cause: Was a loose EFI fuse in the engine fuse block. Wiggling the fuse with my finger while the engine was running would cut the engine off.
Fix: Bending the prongs holding the fuse closer in to each other for better contact.
Yesterday I'm coming back from lunch (engine warmed up) and the engine starts bucking hard, sputtering and seems like it's about to die. letting ll the way off the gas stopped it, but pressing the accelerator would cause it to hiccup again. Made it back to work by cruising without really pressing the gas pedal. It did not happen that morning, going to lunch, or on the way home at the end of the day. I had also filled up a few days before at WaWa, I run 91 octane.
Sometimes at stop lights it bogs down for a second or two as well, Any ideas what happened yesterday; should I chock this up to an injector clog and jsut throw in some STP? I'll be pulling the plugs to check them for deposits. I pulled the silencer off to hopefully blow out any buildup in the exhaust system.
I've had one previous issues with the car:
1) Engine would cut out and stay dead randomly (at lights, when cruising, any time)
Cause: Was a loose EFI fuse in the engine fuse block. Wiggling the fuse with my finger while the engine was running would cut the engine off.
Fix: Bending the prongs holding the fuse closer in to each other for better contact.
02-20-2008, 03:46 PM
#3
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14.7:1 is the theoretical ideal limit, where all fuel and air are used in the combustion process. In the real world, this will cause premature ignition and detonation in the combustion chamber. For daily driving, it's best to keep under 12:1, on racing fuel or meth injection you can lean out the engine further and still operate it safely. I think 13.8:1 is the upper on 106 octane.
For this issue, it's not the eManage fuel map causing it. My first thought was a clogged injector since I bought them used from a tC. Second was a fouled spark plug, third a loose throttle body cable. Since I haven't replicated the issue it's difficult to troubleshoot. The only other things I could think of were a misbehaving MAF or O2 sensor, but no codes have been thrown yet.
For this issue, it's not the eManage fuel map causing it. My first thought was a clogged injector since I bought them used from a tC. Second was a fouled spark plug, third a loose throttle body cable. Since I haven't replicated the issue it's difficult to troubleshoot. The only other things I could think of were a misbehaving MAF or O2 sensor, but no codes have been thrown yet.
02-21-2008, 07:05 PM
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Smaller injectors cause the engine to run lean in the top end. On xB injectors, it was tuned and was sill above 13:1 from 5.2k to redline at 100% duty cycle, not safe for WOT useage. Hasn't happened since, I'm going to chock it up to either a clogged injector or the eManage deciding to fight with the stock ECU, wait and see if it happens again.
09-03-2009, 12:10 PM
#11
nah - it just happened all of a sudden. im wondering if the o2 sensor on my header is starting to get damanged but not yet throwing a code ..... is that possible or will it throw a code as soon as there is an issue? the guy said there is no stage1 codes in the ecu so .....yea ....
09-03-2009, 03:19 PM
#12
It will only throw a code after a few mins of trying to change the fuel trims. If it just does it for a short time, it probably won't throw a code. Either way, that S/C setup runs pig rich and can take a toll on everything in the exhaust system.
09-03-2009, 03:35 PM
#13
^ makes me wonder how good condition my exhaust is in. Say i was to get a 3" cat back ....a new one .... how would my car run w/o FI right now? I think i will be loosing power with a 3" unless i am FI - or is my logic wrong?
09-03-2009, 08:18 PM
#16
It might throw a CEL from lack of back pressure on the secondary O2 because more air is floating around in there. It "might" throw the catalyst efficiency code. Other than that, should run OK.
01-04-2010, 07:48 PM
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Searching my old posts and found this dug back up. To answer my original 2008 question, this issue did happen again, only when it did a rod broke and took out the motor. Took it to a dealer and they said the cause was hydrolock from the CAI. I'm running the TRD design where the filter sits above the pipe. Toyota claimed that water built up in the pipe like a water trap in kitchen sink plumbing. If this was the case, it would explain the engine hiccuping at seemingly random times as water got sucked in, but not enough to hydrolock previously. The intake did have an AEM bypass on it but my understanding at this time is that they are really only effective when the filter is submerged, creating enough of a vacuum to open the valve flaps.
Unfortunately the 2006 TRD CAI is off-road use only and not covered by the Scion warranty. I went to arbitration on this and lost, so i was out $500 for the dealer teardown and $250 for a self-installed replacement engine, not enough for me to push this to court. I found out later that a Tech Bulletin showed that the 2004-2005 TRD CAI were now covered under warranty, but not the 06. I did not have a hydroshield sock on, I'd recommend anyone with a CAI get one.
Build has undergone mutliple iterations since then, a Greddy supercharger and later a Greddy turbo. A third, built motor will be going in soon and with it a Garrett turbo based 365Motorwerks kit. With no warranty, I have free reign on the motor.
Unfortunately the 2006 TRD CAI is off-road use only and not covered by the Scion warranty. I went to arbitration on this and lost, so i was out $500 for the dealer teardown and $250 for a self-installed replacement engine, not enough for me to push this to court. I found out later that a Tech Bulletin showed that the 2004-2005 TRD CAI were now covered under warranty, but not the 06. I did not have a hydroshield sock on, I'd recommend anyone with a CAI get one.
Build has undergone mutliple iterations since then, a Greddy supercharger and later a Greddy turbo. A third, built motor will be going in soon and with it a Garrett turbo based 365Motorwerks kit. With no warranty, I have free reign on the motor.
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