Im going to try and keep it simple
I just got my s13 running from it being out of service for a couple months. Some guy hit me on freeway and messed up entire front suspension. Now that I have it running, idle has been off recently. Ive only been driving it these past 2 days. It wasnt moving for almost 3 months. When coasting in neutral going around 45 mph, car idle bogs down and wants to stall out but them goes back up when at a complete stop. Even at a red light, idle goes up and down. Drops to about 400 rpms and them goes up to about 1500 rpms. Another thing to note is the temp gauge has been acting up too. Im assuming that could be my coolant temp sensor. I bought one from Nissan. As far as my idle goes, i hear IAC valve? Throttle body? Again, forgive me for posting another idle issue, ive seen tons but wanted to see if my car was any different with a potential diff problem. Last thing i want to mention is car has been backfiring more often than before. I am running a CXRacing catback exhaust. Ka24e.

Another thing I forgot to mention is when about 3500 rpms in 2nd gear, the car "chugs". What I mean by chug is i feel there is some sort of gas cut within that range. When trying to give it gas at times, it refuses to go and it jerks back and forth. At a stop, it smells like gas as well. Idle has been fluctuating a lot more now

BrianZ32 wrote: ↑

Tue Dec 04, 2018 10:17 am

Another thing I forgot to mention is when about 3500 rpms in 2nd gear, the car "chugs". What I mean by chug is i feel there is some sort of gas cut within that range. When trying to give it gas at times, it refuses to go and it jerks back and forth. At a stop, it smells like gas as well. Idle has been fluctuating a lot more now

Update: So I had this issue before, when i replaced the coolant temp sensor from one that i bought from O Reilly, the car wouldnt start with the new one. People told me to buy an original from nissan so i threw on the old one and it started right back up. I picked up an original one from my local Nissan and replaced it and it STILL didnt turn on. Now it wont turn on at all even with the old one. I can manage to turn it on by giving it gas sometimes but will immediately turn off. It also will not go rev past 2500 rpms. Now, what do you guys think my best bet is? I am going to clean out thr throttle body and try to clean out IAC but im a noob and im still trying to located it (ka24e)
All of the wiring and sensors are old and original so maybe that could be another issue? A local shop told me to check the connections and most connections are blue/green on the inside but it ran fine before. To PROPERLY clean the TB, do i have to remove it? And is it okay for me to spray the throttle body itself? Forgive me for the noob questions but im trying to learn for future reference.

Hmmm, the TPS and MAF sensors can do that sort of thing. So you can test those per the FSM or search here for instructions. Checking wires and looking for vacuum leaks seems like a good idea. Pulling codes from your ECU would be a good as well (instructions for OBD-1 ecu are here somewhere also). Please keep us updated.