DarkSpoon

I bought a 1987 Mazda RX-7 Turbo on friday. It was not running, but that is not the important part. I will list and post what I have done.

Initially the previous owner (As I shall call fucktard) decided to wire up his own fuel pump cut off switch. Aside from the fact he wired it wrong, the fuel pump wouldn't turn on. After I removed his wiring incident, I had noticed that alas my efforts the pump wouldn't turn on. I read through the wiring diagrams and found I could pass the second relay on the fuel pump switch. I was wondering if this would ever be a problem I should look into (It's wired up like an NA would be)

After toiling with the car for a few hours, and doing research on possible outcomes of WHY it wouldn't start, I went for the basics. I pulled the spark plugs not only to find the ones on rotor 1 fouled, but the stench of gasoline. I did the spark plug removal and adding of oil routine to the rotors. After we had the car boosted off of another car, it started (without an oil change). It ran, didn't make noise at first, but slowly degraded in performance. It didn't have the power initially, but it ran. I'm confused about it, I would have my foot to the floor and it would drag to 5000 RPM, but when I hit close to 5000 the motor flew right up to 7000 RPM like it should (Full of power). Would this be symptom of an impending rebuild? I drove it down the street and back only to have the motor start shaking violently and then stalling. Is it the bad oil that could be causing the car to stall and lose compression? (The oil wreaks of gasoline.)

The car smoked as well, I've et to look into whether or not it was the turbo (There is oil on the outside of the turbo) or if it was just the rotor, but how do I diagnose a blown turbo?

I fulled off the air flow box under the air intake and unscrewed the clip on the side thinking that was where the sensor was for air intake (I was going to clean it). Little did I know it was actually chipped in there. It looked like something might have become unsoldered but went back into place when I put the plug back in. This was before I couldn't start the car). Can someone advise me on the plug on the side of the air sensor, the main point of this special air sensor, and if I should replace it or not worry about it.

My last and final question is how do I know if I have faulty injectors which could be leaking and causing my motor to flood?

Currently thats all I know of right now on the motor that is wrong.

DarkSpoon

alrighso I would have edited out the comment about the previous owner but he was just frustrating.

So I have a new problem. I changed the oil and took the battery out of the car to charge it while I waited. after I put the battery back in it won't crank over. everything works, and nothing dims when I crank. there are a few clicks coming from around the car (Of relays clicking when I crank it) but the starter doesn't make a noise. Yesterday we did get the car to start but today it won't and I don't know why the starter isn't starting.

What are possible solutions to this?

greener_dude

check for bad grounds... I know the n/a ' s have several grounds. If you can't find the ground just make your own and ground the engine to the frame or firewall using 16 or 14awg wire with the proper crimps on the end. Poor grounds can do really messed up things, like make your gauges go screwy, or lights go dim, pop fuses, stall the engine, not charge your battery properly... its a long list. Much easier to add more grounds then to find a bad one. If the car has sat a bit the connection could be rusty. fine sand paper should be enough to clean the connection. A good test is to leave something on deliberately ... eg headlights, or leave the defrost fan on. Then tap the negative battery terminal together. It should spark - be careful though.... If it doesn't spark you have a bad ground or what ever you turned on isn't getting power, could be a blown fuse, relay... who knows. If that doesn't work then you gotta start from step one. + from battery goes to starter, then from there to starting relay then to.... you get the idea.

hanman

First off, it sounds like your starter is bad, or at least not working. The grounds are a common source of problem on these cars, but if nothing is dimming when you try and start the car, it sounds more like a starter issue. And by the way, I don't agree with the above post, adding extra grounds instead of fixing the existing ones is not a great idea. You can add extra grounds if you like, but I would clean up the existing ones first, and they are not hard to find. Also, the idea of turning on accessories and then tapping the negative cable to the battery is also a good way to have a battery explode in your face, just an FYI.

Now, with all that said, I would try a couple of things. First, I would either tap the starter with a hammer, or pull it and take it to a auto parts store and have them test it. Also, I would really clean up your battery connections. You have to fix that problem first. Once the car will turn over then you can move on to the next problem.

As for the injectors, I personally think it is a good idea with an older car to have them cleaned and flow tested. I have done this with almost all of my FI rotaries, and everytime they have come back and solved my problem. I would pull the top end of the intake/throttle body off and pull the injectors. Send them to RC engineering or Witchhunter, or whomever you like and have them cleaned.
www.rceng.com
While you are under the intake, the main fuel injection grounds are right there on top of the engine block. It is ring connector at the end of a wiring harness bolted down to the top of the engine. Pull that bolt off, sand/clean up the top of the engine and the ring connector, replace the bolt with a new stainless bolt. Also, back towards the firewall and towards the center of the engine is a small wire bolted to the engine. The wire runs up to a prong connector on the firewall. Clean this connector up the same way. It is another ground.
Replace the spark plugs and see what happens.

greener_dude

The previous poster brought up a good point of safety... sparking a negative isnt the "safest" thing to do but it works well. Think about it, everything that makes or breaks power sparks. The danger isn't the spark, its the hydrogen gas that a battery can produce that blows up. The worst thing you can do is short out a battery by connecting the + and - together. eg. you leave a wrench or screw driver laying on top of the battery and it shorts it out. That's how you blow up batteries. If you suspect the starter check/listen for the starter grinding on the ring gear of the motor. When an abendix gets weak it won't spring the starter gear out far enough to engage the ring gear. This will strip all the teeth of both gears. By having the starter off you could test it with a batter charger or batter and jumper cables.

And yes adding new grounds is a good idea! Either replace the ones that are there or add new ones. "They are a common problem with these cars."

Thanks for correcting me, safety always comes first.

sm84gs

i hate electrical problems. rx7 seem to be famous for them

hanman

"i hate electrical problems. rx7 seem to be famous for them"

Pretty much just the second gen.

Hazard15301

iTrader: (5)

If all your stock grounds are clean and working correctly you will never have a need to run new grounds. You are just avoiding the problem and making more clutter. What are you going to do in a few years when those connections become corroded? Run even more unnecessary grounds? 120 grit sandpaper and dielectric grease are your best friends.

To the OP: If you do decide to clean up your grounds, you will want to be sure you do them all at once. Here is the best writeup for this procedure.

fd3spr0

have you gotten the starter tested?

DarkSpoon

Alright sorry for not replying right away.
I've been puttering with the car and i'm getting places.

I've fixed the cold idle proplem and freed up some RPM by starting to run seafoam through the gas tank (BTW I got it to start)
I used a fresh battery and new plugs and that seems to be working so far.
Now I have a NEW problem. So when you unplug the ENG fuse with the key turned forward, the electric fan is on but the car won't start. The problem is the fuses are all plugged in but it's still making that fan noise and not starting. I drove it around and would stall/flood everytime I stopped (I've replaced the thermo sensor but haven't been able to test it yet), and I pulled into my alley stopped and went to put it in reverse and the car stalled and is now making the electric fan spin without it turning over at all.
What should I possibly start checking?? I'm going to start cleaning my grounds today and hopefully that will get me somewhere