12340987

When the temp dropped below about 40 my car started having a tought time starting up smoothly. It cranks 4-5 times before it starts, and lopes when it does, as if a cylinder isn't firing. During this time the instrument cluster lights are all off. After a couple seconds it idles normally and the lights turn on.

It's friggin cold outside so I haven't checked the CSI.

llcoolpass

very first and simple/easiest thing to check in diagnosing this based on what you said, go get your battery and alternator checked , often done for free at autozone and advance auto type places.

leave the cold start injector out of your diagnostic equation at this point in time.

12340987

I charged the battery full and it's pretty new. I see >14V across terminals at idle. Assuming the alt is fine what else could it be?

It starts fine when the temperature is high or the car is warm.

I have yet to clean the IACV.

I did adjust the AFM by 3 clicks lean.

Would a video of my problem help?

llcoolpass

dont clean the iacv yet . K.I.S.S. at the moment.
the afm adj isn't really a factor here . show up a vid...ehhh i cant see how it would hurt. go for it, but......
i recommed you take your car somewhere with advance equipemnt to test the battery and charging and starting system. it only takes 10 min to check and is free. since you haven't done it, you have not really eliminated those areas which are what i would start with based on what you said. the next things are far more tedious to check and require special tools so i would save you trouble by starting where i started in this diag.

GEORGE_JET

I agree with taking it down and having them check the battery/charging system. A voltmeter give you some good basic information, but the correct testers will tell you much more, and this is important when you are dealing with extreme conditions. I am willing to be that it is getting real cold up the in Idaho.

There is one thing that I do find interesting, in your first post you mention that the instrument lights are off when the problem is present. This may be a significant clue. If the battery had enough energy to start the car, you would suspect that there is probably enough energy left to keep it running. Have you monitored battery voltage while the problem is present? It is possible that are problems with the power distribution. I would suggest monitoring the circuit that feeds the lights. You may have more than one problem here, and the extreme temps are just bringing them all forth at the same time.

GEORGE_JET

If you follow that thought just a little further, the next step would be which other circuits are not recieving full power. The dash lights are obvious, but there are more important circuits.

But check that battery and charging first, do not try to overanalyze the problem until you know the basics.

llcoolpass

yeah i like this by george jet , a possible bad ground connection, could be a few more things, but like he said, and what im afraid of, is telling you too many theories yet since you must eliminate one thing after another. if you can, have someone start the car and watch what comes out of the tailpipe if anything, the color, the length of time it comes and the amount as well as any smell [fuel, normal rich exhaust on cold state, burning oil, nothing, sweet like smell].

12340987

alt and battery were fine, is CTS possible?

GEORGE_JET

Coolant temp sensor is very possible, keep in mind that the ECM uses a different sensor than that coolant temp gauge in the dash. Do not make the mistake of thinking that if the dash gauge is working, that the ECM is seeing the correct temp.

There is also the cold start injector. On your car, there should be a 7th injector located on the far end of the intake plenum ( near the PCV valve ). This injector is designed to inject extra fuel directly into the plenum for 8 sec while cranking, whenever the coolant temp is below 59 deg.

The dash light issue still concerns me, but I would suggest checking the temp sensor and the cold start injector circuit at this time.

llcoolpass

EDIT: SEE THIS POST from Page 3 of this thread
https://www.clublexus.com/forums/5102688-post22.html
and
https://www.clublexus.com/forums/5102720-post23.html

what george jet said is 100% correct[add in there iacv], but i dont think it would address the strange electrical problem that seems evident. but definetely worth ohming out the coolant temp sensor. the 7th injector can be checked too.

i beginning to want to see a video more and more with good audio [so open door or window so we can hear the engine ito the cabin well] with the problem on the dash clearly visible while your starting issue occurs.

also check the coolant and oil, as usual, to see if levels are right and there is not mixing [head gasket fail]. i know it doesnt seem related.

cts:


7th injector ["cold start valve"]
[58 bucks on rockauto, for the 30day warr part]

12340987

I went to schucks and got this CTS, but the threads were too small. Nothing they have seems to look right (except for one that costs $32, which is wrong for a CTS)

Now I realize schucks.com just has one page for the gauge sensor and ECU sensor.

Does this more reasonably priced one look right?

I can tell from just looking at the picture llcoolpass, that those threads are too small.

GEORGE_JET

the one from schucks appears to have the correct connector. Are you sure that the one you are looking at the correct one? Where is it located on the engine?

12340987

the thermostat housing right under the alt.

llcoolpass

thats the right loc i believe. so did you check your sensor out before wanting to buy one?

that pic is correct dude, the reason i put that was so yo ucould differentiat between it and the coolant temp sender which is for the temp gauge in the instrument cluster

GEORGE_JET

My manual shows the location as being near the distributor. The one near the thermostat is for the cooling fan. I think the instrument panel gauge is also near that location. I have not yet found that location of the HVAC controler water temp sensor, but I am sure it is probably around there somewhere.

But IIcoolpass is suggesting, are you measuring the sensor? You are not just thinking of swapping it out, are you? The temp sensor is a very common problem, but there are other possibilities. You should check the sensor first.