Project_Dragon

That is the coolant level sensor on top of the radiator, as far as I know all it controls is an annoying af buzzer and an idiot light on the dash that tells you to put coolant in before you kill the engine.

The coolant temperature sensor is located on the back side of the water pump housing, between it and the dynamic chamber/intake(green colored rectangular connector with a metal retaining clip). You would be hard pressed to rest a box on it with the intake still attached to the engine. And while yes it can cause issues, in my experience it causes a no crank and most people just think they "flooded" the engine and go on about their day attempting to start it till it returns a value to the ECU that results in a proper fuel amount to start the engine (then they go and complain about flooding issues on the internet)... Not rev to 3k and die. There are two ways to test it, first is to remove the electrical connector from the sensor and attempt to start it. The ECU will put in a default value for the sensor, and it will idle fine without it connected. The second way is to read the FSM and do what it says.

Since your engine is starting I doubt these two methods will be helpful.

Do you have the power steering belt hooked up? Do you have the AC belt hooked up?

PnoyRx7

iTrader: (3)

I appreciate the response, yes you are right, I remember it broke on my first ever rx7 and the buzzer was going wild.

I agree, I don't think that is the issue. It starts up perfectly fine. Hell I could do it all day long and it will just keep starting. It just won't do the MAF hand off after the initial start-up, except if someone is holding the MAF open fully or it is unplugged. If it is unplugged it runs like dog doo-doo but it pops the fuse after 1 min in the cabin for the engine. Which is weird because it doesn't do it with the MAF plugged in. Not one popped fuse with the 15+ times I tried to start her up and keep her running or when the MAF is held open, and when it is held open I can keep her running indefinitely and no fuses popped.

I am trying to get some time this weekend to check the wiring anyways.

Power steering is hooked up. AC is seized but I cut the belt off because one day a few years back it seized up while driving and it caused a burning smell.

Project_Dragon

I went through the same thing. It is not the resistor pack, it is not the MAP sensor, it is not the AFM, it is not the AFR resistor, and probably not the CAS unless you f'ed with it.

Remove the power steering belt and report back if it idles.

PnoyRx7

iTrader: (3)

I have never heard of this being an issue... I will definitely try anything once at this point lol.

It steers fine by the way when I could get it running, also when the MAF is unplugged it stays running ish

Either way I'll try it out. If it works my head will implode then explode.

Project_Dragon

The power steering itself is not really the issue, what I suspect is your engine is running on a single rotor. The car will idle with just the one rotor but under the slightest butterfly kiss of a load(the power steering pump) it will die immediately.

PnoyRx7

iTrader: (3)

Hmm, weird. It's pouring currently so I cannot make it outside today.

Wouldn't a single rotor cause massive vibration? The only reason I am asking is that when it does jump up to 3k it does so smoothly. The only reason I could think of if it is only running on one rotor would be it got a deal stuck while sitting (happened before) and I fixed it with a little oil in the chamber.

The car isn't moving anytime soon and it's pouring, wondering if I should just cut it off. I need to replace all the belts anyways. Just don't want to get soaked trying to get it off.

PnoyRx7

iTrader: (3)

Ok so I got the PS belt off, it was misting so I ran outside.

Now the car won't even start... it's not flooded...

I have read about others having weird issues show in humid or rainy conditions. She's been stored in a locker for 7 years so maybe she is just accustomed to a climate controlled environment lol?

Project_Dragon

Yes, the engine would be visibly bucking and look like it was trying to climb out of the engine bay. Please don't cut good belts, it's literally just a few twists of a 10mm socket.

First off before we proceed, did you do anything to the plug wires, spark plugs, or wiring to the fuel injectors? Even just replacing them as a part of a tune up, or getting rid of some old crumbling electrical connectors? No?

Then you have a vacuum leak. Find it.

PnoyRx7

iTrader: (3)

Ah, so it is not doing that. Maybe very minor lumpy-iness.

I got it off, the pulley bolt wouldn't budge after loosing the tension bolt, I gave it a very light whack and it loosened. Belt is safe and sound. No need to worry.

I only did the "oil" trick when I first tried to start her up after the issue started. Thought it was because something was stuck or needed a little help. It helped for 5 seconds longer than the usual start/jump/die cycle I am running into now.

I have plugs/wires/fuel filter in my rockauto cart, just waiting for payday.

Do you recommend a smoke machine vacuum leak tester on Amazon? I thought the car had to be running, or is that for checking vacuum pressure?

Wouldn't it have to be a massive leak to prevent no start/running issues?

I'm hoping the car dries out over the weekend. I literally left it for 2 mins running back to get my tools, it was misting with the hood open. I get back then it's raining and getting wet but not drenched. Hope nothing got ruined.

Project_Dragon

Only if you have no clue what you are doing. I built my vapor tester out of an old Tostinos salsa jar, a cheap soldering iron, some aquarium tubing, a bicycle pump, a Bic pen, some mineral oil, old shop rags, and JB weld. It works surprisingly well, actually. Most of my hack job equipment doesn't. This is one of my rare projects where I am getting more than my moneys worth.

I went down to my S4 tonight and pulled off the air hose that wraps around the intake. Revs up to 2-3k then dies immediately. If there is nothing electrically wrong with the fuel, air, spark.... Or mechanically wrong with the compression... IMO it has to be a vacuum leak.

Edit: And a BIG one too. It'll run like **** with a few minor vacuum leaks.

PnoyRx7

iTrader: (3)

Alright sooooooo....

It still did the same thing but I don't know if it's because it's not cold out it's 20c+ and it started but only went up to 1500rpm then died.

The belt had no effect.

I looked all over the engine bay for 2 hours looking for vacuum leaks and unplugged plugs, nothing.

I was wondering if it would be beneficial to have a plug/wire tester? They are 20 bucks each and perhaps it will knock one thing off the list. Apparently the wire tester can see if it's not consistently sparking evenly.

Also, just for checking, how effective is the piston compression tester method with the relief valve removed?

I had an issue with the back rotor being "stuck" when I bought it, that's why it was so cheap but I fixed it with the oil in the spark plug hole. It has never shown signs of any issues the entire time I have owned her. Now I am starting to worry if it has bad compression or something stuck on the back again as it sounds weird the cranking outside of the car.

Then again, maybe it's not sparking because of a plug being fouled because of the oil.

I'll dig deeper, order new plugs and wires, and do the oil trick with the old plugs and wires since I'm replacing them already.

​​​​​​Edit: just realized that the tach does not bounce when cranking and all the fuses are good. Which is weird because the coils rarely fail according to most reliable sources. That leaves the plugs/wires or back to a bad AFM because apparently it controls the sparks. Is this a symptom or unrelated?

j9fd3s

iTrader: (3)

you can use an Ohm Meter to test the wires. new ones are like 8k Ohms, and the upper limit is 16k Ohms.
spark plugs should just be new

PnoyRx7

iTrader: (3)

I have solved the issue... Get ready... It was... The MAF. I finally grabbed a used low mileage one and plugged her in. She was flooded as well so I put a little bit of oil in the plug holes and she fired right up.

Ironically, she idles better NOW than previously. She used to surge until she was cold, but now she idles even and when up to operating temperatures she purrs...

Just want to thank everyone for their experience and help, and just thought I would reply with my solution. If anyone has an issue on an S5 NA at least, and it starts but then dies after 3 seconds check the MAF first.

I also picked up a low mileage GT 07 Rx8 6spd for a daily so I guess I am masochist for rotaries. I also aged 20 years trying to figure it out...