Please confirm my idea about my misfire!
09-10-09, 05:09 PM
#19
Cap/Rotor did not fix the problem, but it did help... The rotor was cracked, so at least it was replaced now.
However the car still misfires under load. It sounds like a WRX STI with exhaust (you know that very strange 4cyl sound?) under load when it misfires.
I took a video.. you can clearly hear the difference from when the car sounds normal and sounds like it is misfiring....
Around my apt complex its fine. When I am in load (very noticeable in 2-3 gear in this video) it misfires.
http://www.youtube.com/watch?v=lGzBqwLz5j8
However the car still misfires under load. It sounds like a WRX STI with exhaust (you know that very strange 4cyl sound?) under load when it misfires.
I took a video.. you can clearly hear the difference from when the car sounds normal and sounds like it is misfiring....
Around my apt complex its fine. When I am in load (very noticeable in 2-3 gear in this video) it misfires.
http://www.youtube.com/watch?v=lGzBqwLz5j8
Last edited by RedPhoenix; 09-10-09 at 05:28 PM.
09-10-09, 05:54 PM
#20
Lexus Test Driver
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kind of a long shot but worth a try. find a friend with another sc400 and swap ecu's. only reason i say this is recently a friend of mine had almost all the problems you are having and we went through just about all the fixes you have tried and it ended up being the ecu. like i said a long shot but its so easy to try
09-10-09, 07:12 PM
#21
kind of a long shot but worth a try. find a friend with another sc400 and swap ecu's. only reason i say this is recently a friend of mine had almost all the problems you are having and we went through just about all the fixes you have tried and it ended up being the ecu. like i said a long shot but its so easy to try
I did some simple resistance checks...
It was getting late so I only checked both coils, 1 plug wire, and 1 coil wire.
The coil packs are supposed to be 10-14k ohms... mine were 16-17m ohms...
Coil wire was 5k ohms (within spec)
Plug wire was 30m ohms...
k = kilo
m = mega
mega ohms is a HELL OF A LOT more than kilo ohms...
So my wires AND my less than 2 year old coil packs are out of spec... by a lot....
09-10-09, 07:59 PM
#22
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It seems like you have covered almost everything man. Have you tried re-gapping the plugs? A buddy of mine had a similar issue arise with his bpu SR. He looked into re-gapping the plugs and the problem was fixed believe it or not. I still felt like whatever the underlying problem was, re-gapping the plugs wasn't the actual fix but the motor is solid and is still running like a champ a year later.
09-10-09, 11:38 PM
#23
I had the same issue with my sc300...i changed my spark plugs and no more misfiring or hesitation. OneJay can verify how bad it misfired....sounds like your vid. I'm a noob at fixing cars but I bough NGK platinum...not sure if that is any difference than copper. GL buddy
09-11-09, 09:42 AM
#24
My vote is as follows after reading this thread....
-Timing
-Check ALL your wires in your wheel well wiring harness, i had the SAME exact problem and i spent well over 1000 Dollars on parts just to find that there was a small break in one of the wires running under my wheel well..
-Try another ECU, i know it seems like it wouldnt be a problem, but i know that some times with this electric mumbo jumbo things can get messed up
-Check all the wires and harness's in your engine bay
-When i did my plugs and wires once, Without knowing i pinch one of the Coil wires with the plastic cover piece, Making the wire "ground" out to the block, 3 cylinders wouldnt fire...
-Check your coils, clean the connections
thats all the things i can think of
-Timing
-Check ALL your wires in your wheel well wiring harness, i had the SAME exact problem and i spent well over 1000 Dollars on parts just to find that there was a small break in one of the wires running under my wheel well..
-Try another ECU, i know it seems like it wouldnt be a problem, but i know that some times with this electric mumbo jumbo things can get messed up
-Check all the wires and harness's in your engine bay
-When i did my plugs and wires once, Without knowing i pinch one of the Coil wires with the plastic cover piece, Making the wire "ground" out to the block, 3 cylinders wouldnt fire...
-Check your coils, clean the connections
thats all the things i can think of
09-12-09, 01:12 PM
#25
Thanks for the reply.
Like I said in my previous post, I checked both coils and some plug wires and all of them were HORRIBLY out of spec. The coils were over 2000 times the "spec" resistances. Same with the wires.
I ordered my wires to make a custom 8mm kit (in red to add more hp of course) and I warrantied out my coils and picked up 2 new ones . And the resistance of those is 13k each... where my old ones were 30M each.
I wont install the new coils yet until the wires are done. No need to put stress on new coils with high resistance wires.
Like I said in my previous post, I checked both coils and some plug wires and all of them were HORRIBLY out of spec. The coils were over 2000 times the "spec" resistances. Same with the wires.
I ordered my wires to make a custom 8mm kit (in red to add more hp of course) and I warrantied out my coils and picked up 2 new ones . And the resistance of those is 13k each... where my old ones were 30M each.
I wont install the new coils yet until the wires are done. No need to put stress on new coils with high resistance wires.
09-17-09, 08:23 PM
#26
just want to bump this up....
both coils reading @ 30M ohms, replaced with 2 new ones, 12k ohms each now.
3 wires were broken and just arcing from the wire to the terminal
1 was at 40M ohms
rest were just barely out of spec.
Replaced them with some custom made 8mm wires... car runs great!
both coils reading @ 30M ohms, replaced with 2 new ones, 12k ohms each now.
3 wires were broken and just arcing from the wire to the terminal
1 was at 40M ohms
rest were just barely out of spec.
Replaced them with some custom made 8mm wires... car runs great!
