1990 240SX Idle Problem

[KASilvia90]

I have been on here trying to figure out my idle problem before. After I did some more research and tried more things, I have come back with beter details of my idleing problem. ITs a 1990 Nissan 240SX KA24E w/ A-Trans.

My car will idle at random speeds, recently it cold-started at 800rpms I believe. It will run at 550rpms in drive. During this time the car shakes badly, is running lean and there is a different sound on just one of the cylinders (cant tell which). It will go glugglugglugglugpschglugglugglugglugpsch etc.

I went into my ECU for some help, but I don't think its telling me my whole problem. The 02 Sensor is registering lean until about 2800rpms, in which it switches to normal (but still noticing the miss/detonate/backfire like sound). I got an error code 13:Air temp sensor and error code 41: coolant temp. sensor.

My car does this from cold or warm starts. It is also random. It can start fine and 5minutes into idle run like crap. It can start like crap and run fine for 2 minutes and back to crap, it just decides on its own. I don't think the coolant sensor would be causing that? My car doesnt change at all with the air temp sensor unplugged.

I have had a leaky o-ring on my 4th cylinder fuel injector, due to weather and work I haven't been able to fix this. It may just be compression related but the randomness isnt adding up.

I don't want to shell out all kinds of money on air and coolant sensors is these are just other problems, i need my idle fixed. I am tired of seeing my car sitting at the end of my driveway not being driven.

Thank you for any help possible. I would like to finally get this problem fixed, I am just too poor to go and replace anything that looks faulty and hope one day I do the right part.

[S13inBatnRuge]

you could try cleaning the contacts on the coolant air temperature. i have a 93 ka24de with auto and mine did something similar and come to find out my coolant air was just unplugged completely. its worth a shot cleaning contacts.

[Ni2s4s0aSnX]

Ok, first check and/or replace the sensor that the ECU threw out codes for. Replace the O2 sensor too, what the hell, that's not very expensive. Just check all of your major sensors while you're at it. Check the spark plugs and wires and cap and rotor and everything, make sure you're running on all cylinders. The the Intake Temperature Sensor doesn't matter if its plugged in or not, it never affected my car all the times that it was disconnected.

[KASilvia90]

I recently replaced the 02 sensor. As for air-temp, i dont know what the deal is. I reset my ECU codes and never saw that one come up again, I guess someone might have tried to start my car when I had my intake off or something.

I disconnected the sensor plug part (where the wires click together, not the actual TPS unit on the t.b.) and checked its voltage on ACC, it read 4.6volts?

I bought new orings and a water coolant sensor, I also replaced the temp switch because i got a new one for free.

I tried to adjust my timing, blind style (retartding/advancing to see effects w/o looking at timing chain or anything else, only a mark where it was before i tampered). Fully retarded it seemed to run just a hint smoother, but still horrible, then mildy worse until i overadvanced it. I dont think timing is the issue.

I am replacing the orings and water coolant sensor this afternoon. I checked my ECU and now it is reading over lean (flashing green light) all the way to redline. I think my car is getting a lack of fuel somehow? I have a new pump, filter and injectors though?