deanshark

Primary coil resistence;
Cold 0.36 - 0.55 Ohms
Hot 0.45 - 0.65 Ohms
Secondary coil resistence;
Cold 9.0 - 15.4 Ohms
Hot 11.4 - 18.1 Ohms
http://airtexenginemanagement.com/pdf/W15.pdf

blacksc4

iTrader: (1)

kinda sounds like a bad ecu, had the same problem, tried checking codes and wouldnt really get one, CEL would randomly come on and off but nvr give a code, car wouldnt stay running unless i gave it sum gas, sumtimes it would start fine and then sumtimes not, put a new ecu in and boom worked perfect

KoukiMonst

if you tried to pull codes and you cant, thats a pretty solid sign of being the ecu.. at least pull it apart, takes a few minutes and it will rule it out!

mklaah

secondary coil resistance on both is 12.5.
primary coil resistance on both is 1.6
Both are coil are cold.
I checked it like in the diagram you provided.

So is the primary coil resistance bad?


Im beginning to think the ecu is bad also. The cel comes on for like 30secs to a min and then runs fine.
This morning it would not start right about 6am. when my wife was leaving to work. When i get ready to leave at 9am it starts right up with no cel.

How do i check the ecu


Thanks everyone for you help.

deanshark

Sounds like both those coils are bad, reading that high on the primary. You said you changed the drivers side coil. Which coils did you check, passenger side and old or new drivers side? Bad coils is possible b/c it runs bad when it warms up to operating temp. Like everyone is saying though, also check the ECU. All ya gotta do is remove it from the car, it's bolted up inside the passenger lower dash panel. (I think it's 3 bolts) Then remove the covers on the ECU and look for any capacitors leaking. You can see what it's not supposed to look like in this; https://www.clublexus.com/forums/ls4...-repaired.html If you have steady hands and good eyes it's not too hard to change any caps. That's what I hear, I haven't had the displeasure of doing any of them....yet.

mklaah

I replaced both coils. I took out the ecu and saw some slight leaking. I cleaned it up and put back in. When I put it back in I saw moisture near the ecu. I think maybe the moisture that is near the ecu might affect it. Is the moisture coming from the evap? I also notice the carpet wet slightly.

Dtwillis5

Could be coming from the evaporater if you low on refrigerant that would make your coils sweat when you run the ac or your sunroof leaking .

Dtwillis5

Or have too much refrigerant

deanshark

If the caps were leaking then they need to be replaced. Cleaning them isn't gonna do anything. Also, moisture is not good. Was there moisture in the ECU or just around the outside where it's mounted? Find the cause of that moisture and fix that b/c if it's not the cause of this problem, it might cause problems in the future.

mklaah

I cleaned the ecu caps that leaked. The car is working great now for about 1 week. I also have not turned on the ac since it has cooled. So I think the prob will come back when I use the ac or defrost.

SkulCracka

you also like they said need to repull the ecu and replace those caps that were leaking.

cj44

Hi I'm new here, but while reading posts I came across this one and it is very similar to my situation. but I have one more question to add, since I just had my fuel lines dissconnected and I probably have old gas( just bought it) is there any need to "prime" the fuel system after having it somewhat drained, or will the bad gas keep it from staring altogether?
Thanks and sorry to tag on to this post, it was just so similar to my situation.

mklaah

Update. Car has been running like a champ. It has not had any issue. I believe that when I turn the ac on it will act up again. Some how that moisture in the evap is leaking and it is tooo close to the ecu. That is what I think. Not sure though till next summer.

tonyfazt

if u havent change the ecu