Hey guys

Ill just fill you in on what's been happening with the ol' ca18de s13. It hasn't been running to the best of its ability lately and has had a rough idle, running a bit rich, all things I've read a blocked injector causes. So i spent a day taking them out, i took all the old seals and filters out, grabbed myself a 9 volt battery and some alligator leads (To power and open the little valve thingy in the injector) then got some throttle body/ injector cleaner spray and taped the nozzle to make the nozzle wider and make it air tight when i stick it in the top of the injector and sprayed it through to thoroughly clean out inside of them. this worked a charm you could see the difference almost immediately.. So when i was done with cleaning them i put all the new filters and seals etc back in and popped them back on the car. At the same time i upgraded to a bigger alloy radiator and replaced the thermostat with the recommended oem (i think the number 82 rings a bell?) one. Got the high flow one because it sounded fancy Annnyway back on track once everything was all in and checked over ready to go of course i fired over the car. It ran like a rotary and wouldn't accept any throttle input without the engine dying. Which hey i expected this to be somewhat normal, i mean the injectors would need fuel to be flowed through of course But then the following day (today) i went to start it from cold and it did the same thing Running like a rotary and wanting to cut out with any throttle imput.. sounds to me like its getting to much fuel (which would make sense if the injectors are now unblocked) but after no more then 2-3 minutes when the car warms up it is drastically better then it was before doing the injectors! Runs so much smoother and i'm positive it has increased the power slightly.. So basically the problem is just when its cold. Was thinking it could maybe be choke related or something? not entirely sure. if you need anymore info please ask and ill let you know..

Few things to note, before i did the injectors the car had no problem cold starting. Just didnt run 100%..

Now that the injectors are done (NO LEAKS ANYWHERE ) it sounds like a rotary(When cold starting) and wont rev without dying for the first 2-3 mins before it warms up. But like i said once it warms up it runs a charm. love it. Also one thing to note not sure if it's relevant or not the car use to idle around 800-950ish and now it sits around 4-500?

Thanks guys!

Would post some photos but i have absolutely no idea how.

I think i figured out how to attach photos

Pssst! Your turbo is missing and the steering wheel is on the wrong side! LOL! Seriously though, it sounds like an issue with the cold start valve. What RPM is it idling at when it's cold?

Ohhh how i wish it was turbo! Would feel kinda funny having the steering wheel on the other side though

It idles cold at 400rpm. But it sits there perfectly (Needle doesn't move at all) on idle. Only starts being a rotary when you apply throttle.

That's what I figured. There is a valve underneath the throttle body that is supposed to open when the engine is cold and increase the idle to approximately 1500rpm. It has a nasty habit of sticking shut/open, usually shut. When that happens, the idle isn't high enough when cold, so the engine runs poorly until it warms up. It's amazing you're even getting it to start. Mine wouldn't start when that valve failed.

Can this valve be cleaned / removed and cleaned? Is the an image of it lying around?

I think my DET has the same issue, when cold it idles around 1000rpm where it should be 1500rpm.

Is it directly under the TB?

silvios, did you find out how to clean that valve?


looks like I have the same issue, I tried replacing the valve with 2 spare ones, no luck (or maybe all of them are stuck)

it's likely they're all stuck. I've tried cleaning about 6 of them over the years and it's never worked. A new one always fixed the problem.

there's a small opening on them, but I haven't tested their resistance, if that'd show anything...if they are all stuck is there any way to bypass that valve during cold start up?

oh, also could the engine temp. sensor be broken as well? any way to test it besides ECU diagnostic mode III?

You can test the coolant temp sensor by checking the resistance at certain temperatures I believe. Not really a way to bypass the cold start valve unless you crack the throttle body by using the screw beneath the throttle pulley, but it takes time to get it right. You are better off replacing the cold start valve (aka air regulator)

thanks! yeah, according to the FSM the sensor output different ohms at 20 and 80 degrees or something like that.

what would be a good replacement? has the Autozone part #AC422 for a 92 sentra you mentioned worked out well?

I believe I used one from the 240sx.

I don't think he's in the US, so that's not going to help him.

AutoZone part number SU405. Fits a 91 - 94 Sentra with the 2.0L - This is for the temp sensor (if anyone was wanting to know lol)

I guess you're talking about the air regulator for the cold start, if so then yes it is Part number AC422 Sorry about that.