rx-7ames

iTrader: (1)

The title states my problem, this is what happened. I changed out the alternator to try to get rid of squeeling under the hood. When I test drove it I noticed the voltage regulator wasn't working. The voltage was going very high and then the car completely lost power and died. This is what it is doing now.

The engine turns over but will not start. I am getting good spark from each plug. I did a compression test since I had the spark plugs out and that is good. I tested the fuel pressure which is also good. Next I went to the injectors. They looked like hell so I ordered some rebuilt plugs to replace them. That didn't help. I am getting power to the injectors but that this point I can't think of what else can keep this car from starting. Any suggestions on what to check next would really help.

Stripgear

iTrader: (2)

If your injectors "looked like hell", check the connectors for corrosion. When I rebuilt my engine, I had the same problem. New connectors from NAPA solved the problem.

RX-7 Chris

iTrader: (19)

Is the fuel pump working?

andernamen

iTrader: (2)

Check fuel tank and the fuel pump inlet, maybe clogged.

wahootee

iTrader: (50)

Are your injectors spraying/delivering fuel?
the FSM shows how to test this.
Basically leave your fuel rail hooked up, wire the injectors to the rail so they don't fly off when pressurized and put them in a glass jar so you can see the spray and measure the volume.
You can trick the fuel pump by jumping it at the small 2 prong plug by your AFM. Once jumped, it (fuel pump) will be "on" once the key is turned on.

aeenox

Have u tried push starting the car? I was having the same issue last week when i replaced my alternator. I would try to start the car and it wouldnt turn on. The battery cables were getting hot too. After i tried to push start it started running, then i shut it off. When i went to start the car again it turn on and now is running fine.

Rotaryhaven

iTrader: (17)

check fuses, fusible links, and ignitors. Hopefully you didn't change the alternator with the battery connected. There is a possibility that an ignitor fried. Also, I have seen people change the injectors, didn't replaced the intake gasket or cleaned the mating surfaces properly and the car would not start due to an air leak in the manifold gasket.....

LongDuck

My bet's on the Fusible Link block at the driver's side strut tower. You'll notice this dark brown block of plastic has markings on it for the various fusible links, and one of them is marked 'INJ' for injectors. If that link is burned out - the injectors won't get pulse information and will not fire.

Check all of them, and recognize that just because the link is intact doesn't mean that it's still passing current correctly. The concept behind a fusible link is that it functions as a fuse, but also tolerates a higher load during start of current flow that would normally blow a 'dead-blow' fuse - and is why Mazda chose to use these for critical components like your headlights and fuel injection system.

Have at it and let us know what you find,

rx-7ames

iTrader: (1)

I didn't realize so many people replied. I need to check my notifications. I did some work but I have been out for a while due to a motorcycle crash. Anyway:

Yes. I have great pressure.

I cannot get them to spray.

No. I don't think this will help.

I checked and double checked the fuses, then had a friend check. No fusible links. I always disconnect the battery when working on things like this because of past lessons learned. My ignitor is good. I am running an MDS ignition box on the leading and the ignitor on the trailing. Spark is good. Gasket on intake looked fine too but it is worth mewing in mind.

My next move is swapping the ECU. I have one on the way. I can't think of any other reason the injectors wouldn't fire.

rx-7ames

iTrader: (1)

I am really stuck now. I just swapped the ECU out with a used one and that didnt change anything. I have no idea what to try next. I might need to go to a rotary specialist.

rx-7ames

iTrader: (1)

I have no idea what the explanation for this is, but I changed out the trailing ignitor and it started right up. This is so weird because it was getting spark but I could not get the injectors to fire. Oh well. Makes me glad I donor do this for a living.

LongDuck

You're back! It always sucks to provide troubleshooting information and then the guy disappears...

So, your trailing ignitor may or may not have been the problem, but you might want to put the original ECU back in and mark the one spare as "Tested Good on 6/23/2014" or something. Also, the connectors to the trailing ignitor are what I mentioned before about needing to be working so that the computer gets a firing signal for the injectors. If trailing ignition is out, there is no signal to the ECU to tell the injectors when to fire, which is back to your primary problem.

Glad you got it fixed,

rx-7ames

iTrader: (1)

Yeah, me too. Now I am trouble shooting a battery drain. So far my radio and two amps are pulling a current with the key off. I guess I fried more than the ignitor.