Idle Issue

[Codelicious]

Hey everyone, I just got my 240 yesterday and am having an issue with the idle.

When the engine is cold it idles very rough and usually dies if I don't lightly step on the gas. Than once it gets warmed up it sometimes idles fine at 1k but than sometimes it jumps to 1200 and than drops to like 500ish and than sometimes it just dies. What could be the cause of this?

I have a 1989 S13 Fastback with a KA24E.

Will post pictures tomorrow btw

[Codelicious]

I will be trying this tomorrow.

{edit} Link removed due to going to a competing forum... {edit}

[jkollerS13 :]]

mine did this and i put in a new intake manifold gasket and now it doesnt die on me.

[Holvinator]

it sounds like a bad Mass Air Flow sensor. Does it trow black stuff through the muffler when it tries to go back to 1,000 rpm's?

[Codelicious]

it sounds like a bad Mass Air Flow sensor. Does it trow black stuff through the muffler when it tries to go back to 1,000 rpm's?

I haven't seen any black smoke, but my step dad said that he saw some the other day. I adjusted my idle screw and it is idling at about 1k now just fine on a cold start. Buth than when it gets warned up something makes the idle go from 1k to about 1.5-2.

I'm going to check for vacuum leaks when I get the chance. But I don't hear a hissing sound.

[Holvinator]

see if you have a friend that will let you borrow their MAF sensor so u can try it in your car. oR go to a 240sx specialist shop and c if they have 1 laying around that "u will buy it" but u gonna try it 1st cuz u "think" that is whats wrong with ur car...if it fix the problem buy it from them...or just tell em' u gonna get some ca$h and that u will be back.Then find it cheaper somewhere else lol.

Also if ur car is in a garage look on the floor bye the muffler area and look for some black stains,it feels like grease when u touch it. Hope u get to fix ur car soon. good luck

[Alteris]

I have a Nissan 240sx with a KA24DE it has idling problems and I was wondering how many wires are suppose to be in the Maf sensor harness to the connector mine only has 2 wires and 3 female pins on the harness and 4 pins on the Maf sensor itself...is that suppose to be like that?

[compactfean]

should be 3 pins and 4 wires. 2 of the wires are black grounds that are on the same pin, one to chassis,one to ecu. Have you checked to see if you have 12v ti the iacv motor when key is on.

[Alteris]

No I'm gonna have to check that and find the wires I'm missing...I also need to hook the iacv motor up got to figure out where to vacuum line go to

[Alteris]

Nevermind on figuring out where the vacuum hose goes I done that

[Codelicious]

So checked my ECU and got Code 12. So I replaced my Mass Air Flow Sensor. The problem is still going on though..

What should my next step be? Cleaning the IACV?

[compactfean]

So code 12...mass air flow sensor is code 12....your missing a wire to your mafs....why would you go buy a mafs if you havent figured out the wiring issue? Start with the obvious.

[Codelicious]

I'm pretty sure that there are 3 wires there. Isn't that how many there are supposed to be?

----- EDIT -----
Oh, I think I know what happened. You got me confused with the other guy. lol I have all my wires..

[Mazza]

With my RB swap I had a problem with my MAF, the wiring was fine but first I ran new grounds and 12v power and when that didn't help, I opened the MAF and found that the pins that go from the wiring to the pins on the MAF were bent and had lost solder, I re-soldered them and it was fixed.

I wouldn't go as far what I did, but it does sound like there's a wiring problem here. Try and test for continuity between the shielded wires.

[Codelicious]

After replacing my MAFs my idling issue has changed a little bit.

Now during a cold start it idles fine at 1k (how it is supposed to), but than when it starts to warm up it cost up to about 1.5k. Does this sound like the IACV or more along the lines of a vacuum leak?

I am waiting for a day off to take off the IACV just in case something goes wrong because I use my car for work so I can't be without it.