sc710

So i have been searching all day and im stumped. I started my car this morning and its running fine. Go to leave for work put it in gear and it has a misfire. so turned it off did some searching checked the codes and got 14 and 15. seen similar problems where the car doesnt run but mine still does and if i let it sit for a bit start it and it runs fine again for a few minutes or you put it in gear then misfire. im really confused has been running no problem then this. any help would be appreciated thanks

sc710

really? nobody has anything. i need help this is my only car so without it i cant get to work. please help

SC400slide

iTrader: (11)

14 = Igniter signal, 15 = Ignitor signal. I bet that your coils (or ignition coils) went. While the vehicle is on idle, unplug one at a time. If the idle changes, you know that coil is good. There are two on your SC.

sc710

ok thanks thats kinda what i was thinking but since this is my first sc i wanted some imput before i spend money on something i dont need. last night i started it drove 3 miles to town started missing when i got there. then on the way back it got way worse. crazy cause it drives fine all the time parked it for 2 days to fix my headlights and replace the front upper support and hood hinges now this lol.. i give that a try i appreciate it.

RandC

It's also a good idea to check for a faulty ground connection on the engine block. I believe the ignition and efi grounds are connected on the back of the left cylinder head.

sc710

So went out started it ran fine had to wait about 5 minutes with it running till it started misfiring. Tried unplugging the coils and the car died both times. Not sure what that means.

sc710

ok ill check the grounds

SC400slide

iTrader: (11)

That means your coil packs are good. Moving on to different things. Check the grounds like mentioned.

sc710

been trying to search for grounds. did they decide to hide a few? someone said that there might be moisture in the gas tank cause when missing it runs fine for a minute then misses then fine for a minute then misses again.. or could it possibly be my altenator going out on me and not sending the right amount of juice to the system?

SC400slide

iTrader: (11)

Grounds.
https://www.clublexus.com/forums/sc-...nds-sc400.html
https://www.clublexus.com/forums/per...for-sc400.html

sc710

thanks for the links. the pictures wont come up anymore so i cant really see where they are. but i guess ill do some digging around under the hood again today.

jkieffer12

did you ever figure this out? i have the same issue in my ls400. Cold start it runs great but starts to miss as it gets warmer and i only get code 14 and 15

SC400slide

iTrader: (11)

Did you test ignition coils? My 93 SC400 did exactly this when the passengers side ignition coil went out. Running cold it would run great and had perfect response on the entire power band. Once it warmed it it would misfire and bog down under light throttle, but hammer and it goes. however, I had no light.

jkieffer12

i put two new coils in and the condition didn’t really change.