KA24DE S13 Idle Problem, Please help!

[AeonTorpor]

Ok, so I swapped a newer (94) KA into my car for the blown one (91 original).
I have many new parts in here and it's been running great for the last 6 months.
New:
fuel pump (walbro kit)
fuel filter (z32)
fuel lines (the rubber interconnects)
air filter
spark plugs (single prong)
plug wires
rotor & cap
exhaust mani gasket
and catalytic converter

Again, it's been running like a gem until earlier this month. It began sputtering, it's idle became a bit loopy, slowly it got worse until it became really difficult to turn over. I checked the spark plugs, they had soot on 1&4 most prominently. I measured the ohm rating of the injectors and it seemed as if 2 was dying with a reading of about 24 Ohms and 3 was dead at 300-something Ohms.

I replaced all injectors with those that measured about 11 Ohms (had spares lying around) and it's still bucking a little and it's just a little loopy, I can also smell a strong odor of gas. I checked all vac, gas and electrical connections, they're all fine and connected properly.

The car runs and all, but I'm worried again that this could be an indication of something else. Anyone have any suggestions?

[vmiramon69]

how is ur timing 240 seem to move all the time

[AeonTorpor]

Timing had been fine upon initial install. I wouldn't think it'd skip any teeth or enough of them anyway to do that, could it have? I've kept the RPM below 5k.

[AeonTorpor]

Bumpity bump. It's been stalling recently, I have to break with it in gear and only release the clutch when it's at around 600rpm so that it won't slam the rpms to the floor. Someone!?

[Justinians_2:40]

Have you checked the IACV/IAA yet, that's a common culprit with KA's having idle problems. If that's the case, too much un-metered air is being let in and it's leaning out to the point that it stalls. Just saying the plugs are sooty is kinda hard to diagnose, compare them to a chart like this one: http://www.dansmc.com/spark_plugs/spark ... talog.html

I would check the IACV/IAA first, but if that's not the problem, reading the plugs using that chart would be a good place to start. You can get an FSM here http://www.nissantechdirectory.com/gene ... ofsms.html
240sx > 1994 240sx (KA24DE).zip
open the EC section, you'll find what you need in there.

[AeonTorpor]

I kept tinkering around with stuff and I think I found out what it was. There's a valve with a diaphragm near the back of the intake, it had been stuck. I pressed on the bottom of it and the car almost died, after which it regained idle and is running great. Thanks for your help!

[Justinians_2:40]

Not a problem. Hopefully that solved it and you won't have anymore issues, good luck.

[AeonTorpor]

Here we are in May again... And the Idle problem is back. So Obviously it's temperature related. Anyone? Exact same issues as before. That valve doesn't really do much other than nearly make it stall.

[4cefed]

I believe that's the EGR you are pushing on. Problems with that and the IACV will cause idling issues. Have you removed the IACV and cleaned it out? Where are you smelling gas? Under the hood or in the exhaust? This could also be related to the MAF or the TPS.

/Zombiethread

[davidoliva]

Most 240sx's eventually have a problem idling. This is related to the IAA valve which control the air mixture during idle. The two options to fix this are to have a dealer adjust the valve or simply have it replaced.

The symptoms are clear: as you hit the clutch or lay off the gas and the car begins to slow and idle the RPMs may drop (sometimes quite rapidly) to extremely low levels, sometimes actually stalling completely. If this is happening have someone check out your IAA valve and you may wish to clean all the ground wire connections for the car's ignition and injection system.