Cold Start idle problem...

GRRR!

It just never stops...:( ok, now when i start my car on a cold start it will stutter like hell, and will die if i dont give it gas. and once i give it gas it hesitates and rpms will take a while of bogging before the come up.

When i installed my BRAND NEW air regulator like 2 weeks ago it was taken care of. the problem was solved. now, after this damn brake fluid leaked through my master cylinder into my brake booster and got inside my engine my car is doing this shyt again.

I know its not my boost leak cuz after i fight with the cars idle problem for about a minute or 2 the problem goes away and the car goes back to normal. Can anyone plz give me kind of hope/info/solution/salvation?

can the temp switch cause this?

how about a vacuum leak? You should fix that gasket or get your intercooler plumbed up.

It does sound like a regulator though. did you get it out of a junkyard or is it new?

My Air Regulator is brand new from nissan.

I hear air whistling around the turbo side of the engine but, i dont think its the turbo. what else can it be on that side? can anyone post a pic and let me know what can be leaking on the driver side of the motor? i can hear air. but, when i place my hand on the pipe where the orange gasket goes i dont feel anything.

Well..........if the problem goes away after a couple of minutes and it idles smooth, I doubt you have a vac/boost leak anywhere. My guess is if brake fluid got sucked into the vac system, everything is probably coated with brake fluid, and your air regulator may have some in it, and your I.A.A. unit as well.

Will it eventually go away or?

Well..........if the problem goes away after a couple of minutes and it idles smooth, I doubt you have a vac/boost leak anywhere. My guess is if brake fluid got sucked into the vac system, everything is probably coated with brake fluid, and your air regulator may have some in it, and your I.A.A. unit as well.
The air regulator and IAA unit get their air from the intake tract, not the manifold itself, so, I doubt very much that brake fluid could have gotten in there. The only place it could have gotten would be directly into the intake manifold, but that should be well burned off by now. Have you run a diagnostic on your ECU?

Nope, i dont know how to run a diagnostic on my car.

If you can show me how then i will.

I have an '87 MarkII, so my ECU has 5 different modes. I believe yours is a bit different, so I can't help you out on how to do it. Do you not have a service manual? If nothing else, get a Haynes manual. You'll need it sometime in the future anyway, and it should go through the diagnostic procedure for the ECU.

Its doing the same shyt my car used to do when i had a bad air regulator.

Does this mean i need a whole new one which will cost me another 80$ :(

What about the electricl clip that goes to the top of the air regulator can that have gone bad? where does that go connected to?

Plz help, i need my car before the 10th. its the drift event.!

You can pull off your air regulator to check if it's still good....the shutter should be open when engine is cold, and closed when engine is warm.
Also the shutter should open and close smoothly with a screw driver.
To check the electrical connector, unplug it from the regulator, and turn the car to "on" and using a volt meter stick the probes to each connector.....you should get a volt reading.
Also check the connectors on top of the regulator.....continuity should exsist.
To check for codes....the easiest way is to pull out the ecu from the kick panel so you can gain access to the lights and mode selector screw or switch.
In the '84 FSM it says:
1. Make sure diagnosos mode selector is turned OFF(CA20) or fully counter clockwise(CA18ET)
2. Turn ignition switch to "ON"
3. Green and red inspection lamps should stay on.
4. Turn diagnosis mode selector "ON" (CA20) or fully clockwise (CA18ET)
5. Make sure inspection lamps display codes...23, 24(CA20) and 31
6. Write down any additional codes
7. Depress gas pedal then release
8. Make sure inspection lamps display 24(CA20) and 31
9. Write down additional codes
10. Shift tranny (CA20) neutral
11. Make sure inspection lamps display code 31
12. Write down additional codes
13. Start engine
14. Make sure inspection lamps display code 31
15. Write down additional codes
16. Turn A/C switch OFF> ON> OFF
17. Make sure inspectional lamps display code 44
18 Write down additional codes
19. Turn diagnosis mode selector "OFF" CA20) or fully counter clockwise (CA18ET)
20. Turn off engine.
Procedure for memory erasure
CA18: Turn ignition switch to "ON"
Turn diagnosis mode selector screw fully clockwise for atleast 2 seconds
Turn diagnosis mode selector fully counter clockwise for more than 2 seconds
Turn ignition "OFF"
CA20: Turn mode selector to "OFF"
Disconnect control unit harness or battery cable for more than 15 seconds
Reconnect harness or battery cable.

If you get some codes let me know and I'll look them up......some of them should be listed on top of the ecu
Hope this helps!!

When the engine is cold i pulled out the Air regulator, and it was barely open. it had a holso i stuck a screw driver and i would open it but when i took the screw driver off it will close again and barely stay open. only a couple cm will stay open.

Could this be a problem?

Well.....it works off of ambient temps......so if it Africa hot in Miami which is most always is, it's not gonna be open as far as if it were actually cold outside.
Put it in the freezer for a few minutes and it should open further.
Also....it only opens about 1/3 of the way when it's cold, and not totally fully open like you would think......this is what I was told anyway, and this is also how my new does as well.

Can there be anything else besides the air regulator, that would make the car bog, and die, in idle? then when warms acts fine?

I have a similar problem with mine. When the engine is cold and when I crank it, it will idle high around 1200 and perfectly smooth. Then after about a minute or so something will switch, and it will all of a sudden drop in rpms and idle rough for about 45 seconds. Then all of a sudden it will bounce back up in rpms and idle perfectly smooth again. It only does this when I crank it when the engine is cold after it has sat for a few hours or overnight.
I did discover if I disconnect the connector on the coolant temp sensor, and crank it, it doesn't do it at all. I don't know where to start.....because it did it with my old temp sensor, and also with my new one.
You might want to try disconnecting your coolant temp sensor and see if it cures it. If it does, then it looks like we're in the same boat! Just make sure you turn the car off before you plug the connector back on. I've heard it can damage the ecu if you plug it back on with the car running.

Yes it sounds like you have the same problem as me and Keith. My car also runs really rich and bogs upon cold start. It will also go away if the temp sensor is disconnected. I have a theory that it may be the oxygen sensor heater element is not getting power for some reason and this is causing the sensor to not responds properly until the exhaust warms the sensor up. The reason i've come to this theory is because the car feels much like it did when my last oxygen sensor failed and because the temp sensor and oxygen sensor work in conjuction. When my oxygen sensor failed i disconnected the temp sensor and was able to drive the car home as when the temp sensor is disconnected the ECU will ignore the 02 sensor. I really need to try the tests in the FSM to see if the wiring for the 02 sensor heater element is functioning or not. This may be why my last oxygen sensor didn't last very long. If anyone has any other ideas please share as this seems to be a problem among a few of us CA18ET S12 owners and so far we don't know the real answer yet. I know for a fact it doesn't involve vacuum leaks or anything to that nature because i've replaced all vac lines with silicone hose and that didn't change it. It is definetly some sort of electrical fuel component causing the problem.

I know for a fact it doesn't involve vacuum leaks or anything to that nature because i've replaced all vac lines with silicone hose and that didn't change it. It is definetly some sort of electrical fuel component causing the problem.
Yeah I agree as I've replaced all my vac lines with silcone lines too before installing new motor along with all new sensors.....and it did it too with old motor too.
I'll check out my fsm and test my o2 sensor hot wire and see if it passes or not.

As far as I know, on cold starts, the car should idle high until water temp is around 80degrees. In cold start mode, the engine does run rich, that is normal. After water temp reaches 80 degrees, it comes out of cold start mode and will idle down to whatever the air regulator is set at. I too have a rough idle at the moment that I have not been able to fix. However, I haven't replaced my air regulator, so that may be where some of this issue lies.

True that the car should run rich at first however this is more of an excessively rich/bog condition with mine. I also have a new air regulator and it didn't change anything. I have also played with the adjustement nut on the air regulator to increase the idle speed to let more air in and it still does it. Definetly an electronic fueling issue of some sort. I seem to recall Bart having some sort of oxygen sensor heater problem with his car a long while back? Bart if you read this can you comment on that?

Hey guys, I am finally happy to anounce that the car gods are finally letting me breathe a little.

It turns out that when i disconnected the vac that goes into the booster and pu my thumb on it the car idled perfect with no probems. so, since i installed a new master cylinder im here thinking fuk where is the booster leak coming from (i can hear it) so i put my fingers around the border of the master cylinder end (part that connects to the booster) and felt a lil air coming out.

So i went to Autozone and bought a universal mr gasket and made a template put it on the master cylinder screwed it in tight and my car now idles beautifull again.! :)

Oh happy days... :) :)

Sweet...............good job man

wow i jsut found this thread i have teh same prob but in fact i have a ca20e motor. I never tryed disconecting the coolent sensor but i might look in to thaty ok this is wat happened unhooked the batter the sensors and everythign to replace my intake manifold gasket. THen when i was done i reconected everythign started my car and it idled nice at 1500 rpms u knwo to warm up i was liek damn thats really good then after liek 15 cek it droped down and idled liek shit so i really dont knwo wats wrong . anybody w their own ideas that have figured out a solution