Ka24de dies under throttle

[pooknasty86]

So I have a 1991 240sx with a 1994 Ka24de swap harness and ECU.

The problem is that it'll idle for about 4 to 5 seconds and then it boggs out and die under throttle.

Things i have already checked.

- checked ignition and timing all perfect.
- new distributor, cap, and rotor, plugs
- oem fuel injectors checked ohm reading 1.1 to 1.3 there clicking, using a screw driver.
- checked all sparks plugs smell like it's running really rich.
- checked fuel line coming from fuel filter it's getting fuel.
- checked fuel line coming from the regulator to return line.
- checked the knock sensor it seems to fluctuate way past .56 ohm multimeter set on ohms 20m ohm. Even though ecu gives me a code 55 all ok?
- Is it possible a Bad MAF sensor or maybe a Tps sensor what would cause this issue?

I'm really stomped hope I can get the right help.

[Kis4Kouki]

I' would check voltage I believe it's a .5 volt for signal wire for the Maf since your one of the rare people that know how to use a voltmeter. Also make sure coolant temp sensor is plugged up as well. Could also be a vacuum leak.

[pooknasty86]

Awesome thanks for the reply. I'm trying to slim it down but I really think the knock sensor is bad but don't know if it would cause this issue. Do you know what the specs are on how much resistance there should be?
Which vacuum lines are critical?

[w0nderbr3ad]

Resistance for ka24de injectors should be 11 ohms.

[Kis4Kouki]

Yeah it will run with a bad knock sensor. I believe all that will do is make for richer fuel mixture and back of ignition timing. I have a knock sensor I believe if you want it.

[pooknasty86]

Ill double check on the fuel injectors tomorrow might of had it on the wrong ohm setting. But it seems like this problem is being caused by my MAF sensor and also could be vacuum leak somewhere. Ill keep up to date been working on this car since it was given to me.

[zombiewolf513]

You need to make sure anything youre checking the resistance of is unplugged or else your reading will be wrong. Id check for vacuum leaks too, especially around bended areas of molded lines

[pooknasty86]

Yes i always make sure that i check the actual resistant with anything hooked up. Checked the injectors today. Cylinder #1 11 ohms #2 11 #3 11 #4 11 glad I know the injectors are good.
For the MAF I'm getting 3V off the signal wire so I think there's a problem in my harness. I'm gonna get that squared away tomorrow.

Does this dieing problem seem like it's the MAF sensor causing the dieing on instant throttle if so I'm already looking at upgrading it to a Z32 MAF along with the pigtail harness conversion.

[Kis4Kouki]

yeah your car could be going in to limp mode.

[pooknasty86]

Thanks man that could definitely be a possibility. I thought that limp mode still allows you to get to 2500 rpm but then again I'm pretty positive I have a vacuum leak somewhere, gonna just replace them and shouldn't have to worry about any later on down the road.

[pooknasty86]

So I tested the the maf today and back probed it and got a .3 on signal wire but don't get any reading from the harness could it be a bad ecu since I always get code 55.

[Kis4Kouki]

If you have one to swap out I would do it. Could be a bad connections just in case you haven't tried that.