Car not idle, weird air temp. Need help
 

First of, I apologize for posting on a Rx7 forum. I own a Nissan 200sx S13 with a SR20DET (redtop). Most Nissan forums are dead or I cant register for some reason. (already posted on zilvia, but almost no responses)

Anyway, yesterday I started up my car after 1.5 years after upgrading my turbo, injectors, mapsensor, IAT and a Power FC D-Jetro. (map sensor running a vacuum line to the throttle body, hope this is alright)

First start up went great, bit of cranking and it started. Had a oil leak from my oil feed but I fixed that later. (not really idle, but it started after 1.5 years)

So I started again and the RPM was between 800-1100. Not idle, car shaking. Found out that I put my injectors at 0,72ms and it shouldve been 0.04 or 0.02. So I changed that and the RPM stayed between 800-900. It dropped down to 600 for a few seconds but that was only once.

Next start up I read that I should initialize it again, so I removed everything, set my injectors on the right thing again. (66%, 0,04ms) And turned off boost cntl.

Car didnt start at all. Only cranked and thats it. BUT here is the weird part;

When I just have the car on (not started) my air temp says: 10 or 15 celsius, like it should be. But when I start my car it drops down to -8 (first and second start up) and on the last start up when it only cranked it said -34???? I don't think the IAT is bad since it reads fine when the car isn't running.

edit; also my car did start up with boost cntl on, but it doesnt start with boost contl off. I still have to try to put boost control on to see if it starts with that after the reset. (i dont have the pfc boost controller)

https://cimg3.ibsrv.net/gimg/www.rx7...b85e2e9843.jpg

Honestly all help is appreciated.... :(

sounds like your sensor ground or sensor signal wire is crossed with chassis ground, some other signal, or power somewhere. trace those 2 wires and make sure they are isolated. you'll get more help if you sell that car and get a more proper ride. ;) jk

Alright thanks, ill check it out in a few minutes.

hahah i wish i could afford a rx7 :( poor student here

Alright, your tip worked. My ground wire was hooked up to the wrong one. Fixed that, initialize it again, started the car and it was around 850-950rpm. Air temp stayed at 15 degrees and didn't change a single time in 10 minutes.

My other issue tho, during the selflearning process you have to turn on the A/C and I don't have that. So I thought using my fans on high would do the trick. However, when I do that my RPM drops to 480 and the car does some weird shit. I filmed the hand controller: https://www.youtube.com/watch?v=GZXVeiSi1y0


What do I have to do now? My defroster also doesn't work since there are cables missing somehow.

edit; it also doesnt see my o2 sensor. it stays at 0.0v. (the stock sensor in my turbo elbow) I have a wideband in my car but I didn't plug it in yet. Do I have to connect my WB output to the O2 wire?

It seems like your car has a lot of wiring problems.
You would need to load your map and a log of the car idling in order for any type of analysis.

Ye it had a lot of wiring issues. I bought a new engine harness and tried again. Didn't fix my problem. Haven't replied in a while but here is what I've done till now.

Note; The car doesn't rev past 2k. I get a fuel cut around 2k rpm.

New waterpump (old one was leaking)
New radiator (mishimoto send me one that had a leak...)
New thermostat
New O2 sensor
New TPS
New engine harness
Switched the 555cc injectors for my stock ones. (370cc)

At first I had a lot of air in my coolant system. After all the air escaped and the engine could rev over 2k. Best sound ever, I was happy af lol.

Day later, I thought I'd drive it to my front door to clean it and it didn't rev past 2k again... Thought it was the waterpump, thermostat or radiator. They were leaking and I didn't get hot air from my heater so I switched all of it. Didn't work, engine harness swapped, O2 sensor swapped. No faulty sensors everything works fine I guess. It just doesn't rev past 2k.

Today I made a fold in my vacuum line to see if it will do anything crazy if it doesn't get air. Nothing happened. But then when I keep the fold and I rev it doesn't go over 1k? rpm, and without the fold it doesn't go past 2k. Can it be a bad map sensor? I don't really wanna buy one without knowing for sure that the map sensor is the problem. Those damn things aren't cheap.

Would this be the map sensor hose as map sensor problems can cause your problems?

Get a compress air source and a regulator and check what your PFC logs from the map sensor.

Someone told me to use a T on my FPR vacuum and hook up my MAP sensor on it, after I did that it could rev till 4k.

I am busy now with my exams, but i'll try to do that soon, thanks.