Thursday, October 16, 2014 - 07:10 pm, by: Tim Laird(Tim_laird)
hi all. i recently got a 92 sc400, and lately has started running on 4 cylinders. i did the diagnostics and found i was getting error code 15. something with ignition bank 2. ive narrowed it down to the drivers side. can unplug all the spark leads and does nothing. can unplug the coil (unless its the 2 pin wires, then it wont start) and still idles the same, if not a tiny bit smoother. ive swapped the coil packs and still the same problem on that side. i was thinking of pulling aprt the distributor, but realised i have to take the lower cover of, which means belt and all the other stuff to get to it. is there some way of testing the distrubutor without pulling it apart? thanks in advance. and i havnt checked all the leads and plugs yet, being that it has lost all from that distributor. thanks in advance!! im losing it. haha
Thursday, October 16, 2014 - 07:17 pm, by: Scott Vim(1uz1jz)
As I discovered its not too hard to take the lower cover off. Actually you can take the distributor off without taking the lower cover off (its harder with the lower cover on). The passenger side is easier. Have you checked both coils?
Thursday, October 16, 2014 - 07:24 pm, by: Scott Vim(1uz1jz)
Oh and the serpentine belt takes about 20 seconds to take off. If you have to draw a diagram of where it runs. But probably there is a sticker on the bonnet which shows that for you.
Thursday, October 16, 2014 - 07:28 pm, by: Tim Laird(Tim_laird)
thanks heaps mate, ill give it a go. ive seen instructions on here for it too. did you manage to get the bottom cover off without undoing any of the water hoses?
Thursday, October 16, 2014 - 07:44 pm, by: Scott Vim(1uz1jz)
Yeah do not remove any hoses. Take the belt off just to move it out of the way. It stays in the engine bay. It will make things easier if you just take bottom covers off. Drivers side has couple of hidden bolts.
Thursday, October 16, 2014 - 07:50 pm, by: Scott Vim(1uz1jz)
First try unplugging the other coil and see what happens. One coil does 2 cylinder on opposite sides so if you unplug the leads you should be able to tell which coil isn't working.
Thursday, October 16, 2014 - 07:54 pm, by: Tim Laird(Tim_laird)
beautiful. ive got the ones on the drivers side removed all the way up centre of the engine, but got worried when i saw it was one piece straight across and didnt wanna dive in. am i right in saying that there is only one cover for the bottom ? ill get the belt off tomorrow and continue on with going to the other side if so.
Thursday, October 16, 2014 - 08:00 pm, by: Tim Laird(Tim_laird)
ive gone though and unplugged all the leads on both sides again when i changed the coils over to make sure it wasnt the coil. dosnt matter which coil is on what side, its always the drivers side leads that dont make a difference. passenger side and it starts idling really bad and shaking. im assuming that would be down to 3 cylinders as ive tryed it with the drivers side all unplugged aswell.
Thursday, October 16, 2014 - 08:03 pm, by: Scott Vim(1uz1jz)
Have you disconnected the other coil yet? Its on the passenger side down lower then the one in the middle. If you can't find it just follow the lead from the distributor. Disconnect that and try start it.
Thursday, October 16, 2014 - 08:07 pm, by: Tim Laird(Tim_laird)
yeah, ive disconnected that coil before i swapped them over and after swapping them to test. the car wont fire at all without that side plugged in. just the starter motor cranking away.
Thursday, October 16, 2014 - 08:28 pm, by: Robert Day(Lexsmaz)
It wont be the coil or distributor if its down one Bank only as it wont effect just one bank as the leads don't actually just run down the one side some of them cross over cross over from one side to the other bank, possibly injector wiring fault ?? ..
Thursday, October 16, 2014 - 08:33 pm, by: Scott Vim(1uz1jz)
You can disconnect the leads and look for a spark. Start with the coil lead. If it's dark it will be easier to see. Look at the coil with the lead off it and you should see a spark. Don't put your hand there and turn the car off before you change anything. So I'm guessing you will see a spark. Next take out the leads and look for a spark. If all four don't spark it has to be distributor. Eliminate what's working and isolate the issue.
Thursday, October 16, 2014 - 08:38 pm, by: Scott Vim(1uz1jz)
Rob is right if its down one side only its not consistent with the ignition system. I would still look for a spark to elimate it. I'm not sure what that error code means to be honest. If it actually means one side of the motor then it can't be the ignition system.
Thursday, October 16, 2014 - 08:41 pm, by: Robert Day(Lexsmaz)
Four not sparking certainly sounds like the Distributor but Tim said its only down one side / bank, so it wont be the coil or Distributor, have a look at the leads coming out of the cap & each cap has 2 leads going to one side / bank & the other 2 going to the other side so it CANT be the coil or distributor as the leads don't go down all one side ..
Edit ..
Im not to good on my codes either I'm sure if you did a search it would come up, I think with the TT code 15 is a knock sensor ??
In this thread there is a pic posted by Dave Rose that shows the lead firing order so you can what Rob is talking about. It may help if you get stuck on the lead order as well.
Thursday, October 16, 2014 - 08:49 pm, by: Tim Laird(Tim_laird)
went thru and did all that aswell. spark is definately coming out the lead from the coil. can see any other spark when i unplug the other leads. i do head an occassional tick sound, like its trying to spark, but nothing like the other distributor that has full spark.
Thursday, October 16, 2014 - 08:52 pm, by: Scott Vim(1uz1jz)
If it is just the drivers side then yes can't be ignition system but how does Tim know this is case? Also disconnecting one coil makes no difference on one side but the other side it doesn't run at all. Meaning ignition system is very possible. If the right side wasn't working disconnecting either coil would mean it would be running on two cylinders only. So would run worse but both sides should be running equally as bad when disconnected.
Check for a spark on the end of each lead. If they all have sparks then look at injectors or other things.
Thursday, October 16, 2014 - 08:55 pm, by: Tim Laird(Tim_laird)
sorry robert. i missed a few of your comments. i did word it wrong. i mean only one distributor is firing. cylinders are firing both cylinder banks. i was just refering to the ignition 'bank'. ive checked all the leads back to the right cylinder to make sure its firing in the correct order... i was hoping it was gonna be that simple. haha