View Full Version : Ka24de idle help

05-09-2010, 10:24 PM
I have a 1996 240sx. The problem is that i have a high idle. It ildes at 900 rpm. I tired adjusting the idle screw, with the tps off, but no luck. I closed the idle screw all the way and it didn't drop the rpm down the 600 or 700 rpm. Is something messed up?? EX: my car idles at about 900 rpm, if i unpplugged the tps, the idle will jump to 1,100 rpm. Why would the idle go up? BTW my car is turbo. The car runs fine expect for the idle. Any help would appreciate!! THANKS

05-10-2010, 12:14 AM
By idle screw you mean IACV screw? If adjustment by IACV screw didn't work, you can try adjusting the throttle body screw to close it up a tiny bit. Timing could also be a factor.

05-10-2010, 12:35 AM
Where is the throttle body screw located? BTW I have a SAFC install along with a RS Enthalpy ECU, if it matters.

05-11-2010, 01:31 AM
It's on the throttle body, right before the throttle opens there should be a screw/stud that keeps it opened (to a point) when there is no load. It should be a 8mm (wrench size) lock nut with a Phillips head. It's been a while since I've worked on a KA, but there should be a screw to adjust the throttle itself.

SAFC: Are your SAFC settings correct? If you are unsure, list all your SAFC settings (also the MAF you are using, and the ECU's program). And what is the correction data in the 'DECEL' section?

I'll get you pictures of the throttle screw tomorrow if you can't find it.

05-11-2010, 02:55 AM
Yes, the SAFC settings are correct. I do have a wideband and the A/F are where it's suppose to be. It idles @ high 14 to low 15, under crusing high 14 and under WOT low 11's to mid 11's. I'm using a N60 MAF. 4in & 5out for the setting. For Decel, i havent touch that, I'm a running DSM BOV recirculated. I do have a RS Enthalpy ECU tuned for my setup.

05-12-2010, 02:35 AM
Throttle Body: Here is the screw to adjust the throttle body.


SAFC: Your settings are not correct if you are running a N60 MAF and your ECU is tuned for an N60 MAF. Running 4 in 5 out would be re-correcting the ECU's measurement which already has a correction of its own. If you are running a N60 MAF and your ECU is tuned for stock KA MAF, then your 4 in 5 out setting is correct. Otherwise, If you are running a N60 MAF and your ECU is tuned for a N60 maf, you need to run in=out which runs no correction since the ECU already has this done (i.e: 4 in 4 out, 5 in 5 out, all the same).

05-12-2010, 11:44 PM
Thanks 4 the help A70lyte. I adjust the throttle screw and it didn't help. Do you think it's my SAFC? If i unplugged my TPS, my SAFC reads 100% on the Throttle. How can i i make it read 0%?

05-13-2010, 12:56 AM
If you unplug the TPS and the SAFC reads 100% throttle, that should be correct. It will read 0% once the TPS is plugged in.

It would be a problem with the SAFC if you have the in-out settings wrong. It's 4in-5out if your running N60 and ECU is tuned for stock MAF. Otherwise, it's in=out if your running N60 MAF and ECU is tuned for N60 MAF.

When you adjust your throttle body, did you tighten the IACV screw also? It's been a while since I've worked on a KA, but for applications that don't have an IACV, lowering the throttle body too low will actually shut the car down. Since your engine didn't shut down, the IACV is doing its job. Try adjusting the throttle body to a lower level along with screwing in the IACV screw. I am hoping that this will solve the problem.