Sr swap idles funny after warmed up a little

[DinoMan]

So i finished my swap a couple weeks ago and its been driving okay. But i've noticed that when i start my car and let it idle for a bit its starts going up and down. When i first start the car itll idle around 1500. after maybe 30 seconds to a minute the idle is down to about 1000. But it seems when it starts idling lower itll slowly rise up for 2k revs and drop back down to 1300 then slowly back up again. if i give it gas, itll come back down and idle good for like 3 second ands then start to build up slowly and do it all over again. Not sure what the problem can be. Any ideas?

[cotbu]

sounds pretty close to a bad coolant temp sensor, but could also be a vacuum leak or tps etc.
pull codes and post video

[DinoMan]

I replaced the coolant sensor for the gauge recently since i needed the one to match with my cluster. Didnt replace the one for the ecu. Ill pull codes tomorrow maybe ill get something. Thanks for the suggestion.

[240sx-pat]

I got the similar issue after my car warms up the idle will drop and lets say when I come to a stop the car sorta boggs like its about to shut up then the idle will come back up after about 5-6 seconds.

I sprayed some carb cleaner into the hose that connect to your cold intake. I've got a new ECU temp sensor but I haven't changed it yet.

My question is , if it was the coolant temp sensor wouldn't I see the temp gauge acting funny? unless this ecu temp is completely isolated from the gauge then that makes sense.

[DinoMan]

Theres two different sensors for the temp. theres one just for the gauge with just one wire i believe and one for the ecu. The one for the gauge is just for your purpose so you can see the ballpark temp. The other one is for th ecu and what really counts. Stock gauge is pretty inaccurate but its still useful to see what your general temps are if you dont have an aftermarket temp gauge.


This is the one for the ecu.

This is the one for just the gauge.

[cotbu]

Originally Posted by 240sx-pat

I got the similar issue after my car warms up the idle will drop and lets say when I come to a stop the car sorta boggs like its about to shut up then the idle will come back up after about 5-6 seconds.

I sprayed some carb cleaner into the hose that connect to your cold intake. I've got a new ECU temp sensor but I haven't changed it yet.

My question is , if it was the coolant temp sensor wouldn't I see the temp gauge acting funny? unless this ecu temp is completely isolated from the gauge then that makes sense.

No, not normally but if it overheats there an audible and visual warnings. the revving of the engine and rpm fluctuation. Usually happen when the ecu thinks it's over heating, but the temp gauge reads normal (HTE)

You other symptoms may just be tuning, temporarily raise you idle about 300rpm and take a test drive. Any difference?

For the record CTS is the 2-wire sensor and the thermistor (thermal Resistor) is the single wire sensor.

[DinoMan]

Pulled codes and I got a code 11? Which would be my CAS right? How would I go about getting rid of this code?

[240sx-pat]

hey how did you even replaced the coolant temp that thing is a pain to get to if it is where i think it is which is right under the manifold

[240sx-pat]

n/m I got it I had to use a long 19 MM with an extender, also anyone else who might need to change this beware that there is a pin holding down the clip. I was working in the garage with not enough light so I couldn't see it til I got a flash light.

[Leetfade]

Originally Posted by DinoMan

Pulled codes and I got a code 11? Which would be my CAS right? How would I go about getting rid of this code?

Is it saying there is something wrong with the sensor / plug or timing? I'm not that familiar with code 11 but when my CAS wasn't lined up right the car wouldn't even start....

[DinoMan]

I have an isis intake mani and i guess it clears up some space for me to get in there.

[DinoMan]

Originally Posted by Leetfade

Is it saying there is something wrong with the sensor / plug or timing? I'm not that familiar with code 11 but when my CAS wasn't lined up right the car wouldn't even start....

Im not really sure. I just searched for sr codes and got this
Code Meaning
11 - Camshaft Position Sensor

It starts and the only problems are whats stated in OP.

[DinoMan]

I just noticed that the code is for camshaft position sensor not CAS. But those are kinda the same right?

[240sx-pat]

Hey sorry I don't know if you mind me posting my issue in this thread I just saw we had similar issue so I didn't wanna start another one but this is a video that I took

that whining noising is coming from the P/S pump I don't think it has anything to do with this tho

[cotbu]

Originally Posted by DinoMan

I just noticed that the code is for camshaft position sensor not CAS. But those are kinda the same right?

Clear the code and start your car then check codes again. get it up to op temp

cas = camshaft position sensor / tomato tomato

[240sx-pat]

http://www.youtube.com/watch?v=bUVORK_9_-g guys try this link I can't post the vid for some reason

[ultimateirving]

Originally Posted by DinoMan

So i finished my swap a couple weeks ago and its been driving okay. But i've noticed that when i start my car and let it idle for a bit its starts going up and down. When i first start the car itll idle around 1500. after maybe 30 seconds to a minute the idle is down to about 1000. But it seems when it starts idling lower itll slowly rise up for 2k revs and drop back down to 1300 then slowly back up again. if i give it gas, itll come back down and idle good for like 3 second ands then start to build up slowly and do it all over again. Not sure what the problem can be. Any ideas?

dude mine did this for such a long time, would idle fine for a few months. then out of the blue would start surging, up and down. never dropping below 1100 rpms. I ended up replacing my IACV and adjusted it all the way off, then reset the ECU and did a fresh idle adjustment, now it purs at like 800 or so. havent had the problem since.

[cotbu]

It does sound like he needs to adjust the iacv, but also check or set base timing. I also think that adjusting the idle lower without setting timing will cause him to stall.
If that cas code stays gone, check timing adjust idle

[DinoMan]

Unplugged my battery for a bit then plugged it back up to restart my ecu and now its throwing 55 which is fine. For some reason every time i try to take a video of it it decides to go just fine. My timing is good because it was off by a bit previously and had my brothers friend set it right so that should be fine. ive taken my iacv off and cleaned it not too long ago maybe a month so it should still be clean. Havent had time to play with the iacv and adjust it where it needs be since its kinda hard to reach with my intake mani.

Originally Posted by 240sx-pat

YouTube - ‪Idling/ stalling issue‬‏ guys try this link I can't post the vid for some reason

Try taking off your iacv and cleaning it with some carb cleaner. Spraying it down the tube isnt very effective really. just google how to take it off it should be pretty easy, think 4 bolts. and clean it thoroughly spraying it alot and making sure the spring is clean. when your throttle plate closes its up to the iacv to provide air to the engine at idle. sometimes when its dirty it takes awhile to open up and let the air in hence the car dipping down then coming back up after a couple seconds.
As for the whining, my ka ps pump used to whine alot but mostly when i turned the wheel. i just added more fluid in it until it didnt whine anymore and couldnt fill it anymore and i was good.

[240sx-pat]

Originally Posted by DinoMan

Unplugged my battery for a bit then plugged it back up to restart my ecu and now its throwing 55 which is fine. For some reason every time i try to take a video of it it decides to go just fine. My timing is good because it was off by a bit previously and had my brothers friend set it right so that should be fine. ive taken my iacv off and cleaned it not too long ago maybe a month so it should still be clean. Havent had time to play with the iacv and adjust it where it needs be since its kinda hard to reach with my intake mani.



Try taking off your iacv and cleaning it with some carb cleaner. Spraying it down the tube isnt very effective really. just google how to take it off it should be pretty easy, think 4 bolts. and clean it thoroughly spraying it alot and making sure the spring is clean. when your throttle plate closes its up to the iacv to provide air to the engine at idle. sometimes when its dirty it takes awhile to open up and let the air in hence the car dipping down then coming back up after a couple seconds.
As for the whining, my ka ps pump used to whine alot but mostly when i turned the wheel. i just added more fluid in it until it didnt whine anymore and couldnt fill it anymore and i was good.

wow this is good info I will give it a shot and see whats up

[240sx-pat]

I fixed my issue, man it got so bad that whenever I decelerate and put my car in neutral it would die. I ended up cleaning the the shit out of the throttle body and got some maf cleaner now my car idle great doesn't go up and down anymore