So, I am going to start from the beginning. About two and a half years ago I bought my RX-8 used from the Mazda dealer. It had 32,000 miles on it and I got it for a great price. Because of the issues I have had recently got a copy of the warranty history and found out that in 2007 before I got it, the catalytic convertor was replaced and the 4206F PCM Reprogram. It is also still eligible for the Lack of Power MSP16.

It ran great until about a year ago it gave me no issues. Without having any noticeable issue, my car threw a CEL. I tried to scan it with my $150 generic obd2 and it kept saying connection error. I have personally used that obd2 scanner on at least a dozen different cars and my RX-8 is the only one that it would not work with. Since I could not get my scanner to work I unplugged the battery to clear the CEL and it never came back. So I thought nothing of it.

Now, a little over three weeks ago I was driving home from work and I felt a significant los of power. It felt like I was running on just 1 rotor. I parked it at home and I took out that night a couple of hours after I first had the problem. About 5 miles away from home it happened again. I drove straight home and parked it. The next day I replaced the plugs and wires and it seemed to work. For 20 minutes... I double checked the way all of the plug wires were connected and everything was correct.

I then did a lot or research about a crank no start problem and I started testing components. I found 1 bad coil so I replaced the full set of 4. I got my battery tested and it lacked in cca so I replaced it with a new one. I also tested my fuel pressure and it was ok. After replacing and checking those components it still would not start. I then proceeded to go through all of the engine flooded procedures I could find.

I started going through the Mazda TSB engine crank no start procedures. I disconnected the Secondary Injection Pump and the Eccentric Shaft Position Sensor and cracked the crap out of the engine. I put the spark plugs back in and nothing. I also siphoned oil into the engine through both of the vacuum plugs in the intake manifold, one at a time. And Still nothing.. Even though I did not have a CEL I tried to check for issues with my OBD2 scanner. It again would not work and gave me a connection error.

After none of that worked I tried pulling the fuel fuse and pulling the plugs to de-flood it and still nothing. I also tried various de-flooding the engine procedures and removing the catalytic convertor to make sure that’s not the problem. I still could not get it to start. A friend of mine suggested using a high percentage isopropyl alcohol and squirting into the spark plug holes to help solve my flooding issue. It sounded similar to the windshield wiper fluid mod so I tried it, cranked it until it was all out of the engine and put the plugs back in. I still did not make my RX-8 start. Btw, I did siphon oil into my engine after I tried the isopropyl alcohol.

I spent a couple of weeks poking at the car and going through a variety of the de-flooding procedures I talked about and no madder what I did, my car would not turn on. I was having my friend help me over the weekend and I was using my old spark plug wires I noticed that it was sparking from the wire to the rotor housing. The odd part about this is that I disconnected the eccentric shaft position sensor and secondary injection pump. From everything that I have read, disconnecting the eccentric shaft position sensor should disable all fuel through the injectors and spark. The next day I double check what happened I thoroughly de-flooded the engine and disconnected the secondary injection pump, disconnected the eccentric shaft position sensor, removed the spark plugs and plugged in all four plugs outside of the rotors. I placed all of the plugs on metal so they would ground out and hand my buddy crank it. THEY ALL HAD SPARK AND I HAD FUEL OUT OF THE PLUG HOLES... I then removed the fuel fuse to double check and I still had spark but no fuel like I expected.

After doing some research I have come up empty. I could not find any situation where someone had spark and fuel with the Eccentric Shaft Position sensor disconnected. That combined with that fact that I have never gotten my OBD2 scanner to work has led me to the conclusion that my PCM needs to be replaced.

My current situation is as follows:
-My 2004 MT RX-8 Sport Suspension has been out of commission for 3 weeks.
-It has 104,000 (Just out of warranty) miles
-It has no aftermarket modifications
-I redline it every day...
-It recently had an oil change and an air filter change (did both myself).
-It cranks strong, has the correct fuel pressure, and has spark.
-I have Spark and Fuel with the Eccentric Shaft Position Sensor disconnected.
-I have never been able to scan my car with an OBD2 scanner.

Any help is appreciated...

 

Interesting...

Maybe something is wrong with your fuel injectors and they are leaking and flooding the heck out of your engine.

Perhaps you should have them flow tested

 

http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx

 

Take it to somebody who knows what they're doing

 

I did consider the possibility that it is a fuel injector issue. But I am concerned that I have both spark and fuel when my eccentric shaft position sensor is unplugged. Everything I have read says that unplugging the eccentric shaft position sensor will prevent both spark and fuel. That is why I suspect the PCM needs to be replaced. Which would also mean I would need to get a PCM Calibrated and I am pretty sure my key fobs need to be reconnected to the new PCM.

 

The OBD II not working isn't indicative of the PCM being bad. In 2004 Mazda, Ford other Ford affiliated brands went to the new CAN protocol, since 2008 all brands have it. Your scanner will not connect because it is not CAN compliant. I have two scanners one OBD II that I use for all vehicles from 1996 until they went CAN and I have a Harrison Scanner for the CAN compliant.

Why it won't start not sure, but get someone with a CAN Scan to check for any pending codes. Also you didn't mention whether or not your plugs appeared fouled or wet when you pulled them (the old plugs or the new ones after all your checking). If the plugs are wet then it is are flooded. If you have spark and fuel it should start unless the plugs foul immediately. Even a car with a clogged CAT will fire up but then stall out. Spark when the ESPS is disconnected is a mystery though, the TSBs all say it cuts the spark and fuel, not trying to be disrespectful but are you absolutely certain that it is the ESPS plug that you are disconnecting? If you aren't actually disconnecting it, you may be re-flooding each time you are trying to de-flood.

You also mentioned that the car lost power initially and you got it home, changed plugs and wires and it started. What happened then? Did it stall out, lose power again? Then could not re-start? I'm just not certain of the symptom that got you thinking that flooding is the issue (jump from your paragraph 3 to 4) because the loss of power issues are not crank-no start issues, especially since you found a bad coil and replaced all four. Just some thoughts to help.

Have you considered the bump start method? A lot of people have been successful push starting, do a search on that as well.

 

Thank you for the information about my OBD2, i did not know that. Now when i replaced my spark plugs they were fouled and it was about time for me to replace them instead of clean them anyhow. After attempting the de-flooding procedure several different ways, sometimes the new plugs were wet and sometime they looked fine. I think that the reason they were wet sometimes is because i still had fuel even though my ESPS was disconnected. I am 99% sure i disconnected the ESPS, i have been referencing a shop manual throughout this whole process and TSB's. When i get home i will take a picture of what i have been unplugging and post it to double check.

After i had the initial loss of power and i changed the plugs and wires here is what happened. I installed the plugs on both rotors and put the new wires on just the first rotor. It cranked on fine and I drove it for about 10-15 minutes and took the car back home. I then put the wires on the second rotor and it again turned on. After letting it idle on my driveway, it started to sputter after like 2 minutes and the engine shut off. It would not turn on after that so i started going through various de-flooding procedures.

When i get home i will take a picture of the plug that i am 99% sure is the ESPS and also try and get the car to turn on again. I will post what happened.

I guess my main question is how is it possible that i still have fuel and spark with the ESPS unplugged? The only conclusion that i could think of is that my PCM is malfunctioning.

 

the symptoms would be similar to loss of compression. have you done a compression check?

pop a plug and get someone to crank the motor while your thumb is over the hole. (disable the coils or you may get a shock) you should hear and feel three pulses. even if you don't use your thumb you should hear three pulses the thumb just makes it easier to distinguish from the cranking noise.

 

I have not done a compression test because i do not have the fancy rotary tool to do it correctly. I have cranked my engine several times without the plugs in and i did hear a equally spaced sequence of pulses. I have also successfully siphoned oil through the vacuum plugs in my intake. Both of those things make me think that i have compression but it is still a possibility. My main concern is that I have spark and fuel with the ESPS unplugged. It makes me think that my PCM is not timing the spark correctly.

 

a special tester will give little additional information. my car will normally start but it has lost compression on 2 faces of the rear rotor. sometimes it will crank for ages and not start.
how long do you crank for?

 

When my car was running good it would take like 1-2 seconds to turn on. Over time as my plugs got fouled it would take like 4 seconds. When it would start taking longer to start i would clean the plugs and it would be back to the 1-2 seconds.

 

my car with poor compression on the rear rotor can take over 15sec of cranking to start. try cranking longer. tow starting a rotor will eventually get it running. cranking for ages does the same thing.

 

allow me to rephrase my earlier comment, take it to somebody with the proper tools and knows what they're doing

it's nothing personal, just good advise

 

So yesterday i proceeded on the premise that i am a idiot and i fixed it... First of all, i was not disconnecting the ESPS... I found a actual picture of it and i was incorrect. After i figured that out, i pulled my mass air flow sensor and it was dirty. So i cleaned it, de-flooded the engine and after about 5 minutes of trying to get it started it cranked on like a champ.

Here is what i think happened. My initial failure was a ignition coil, this caused the initial loss of power that lead to total loss of power because the plugs got fouled. I then replaced the plugs and wires but the engine was flooded so it would not turn on. To de-flood it i was trying to do the Mazda TSB method but i was mistakenly unplugging the incorrect sensor. This caused my engine to get flooded worse. I then checked my ignition coils and found that 1 was defective. I replaced all 4 but i was still unplugging the wrong sensor when i was trying to de-flood the engine. I eventually realized that i still had both spark and fuel because i had my buddy crank it and i watched what was cumming out of the plug holes.

Yesterday all i did was realize i was unplugging the wrong sensor, de-flood it correctly, clean the mass air flow sensor and after about 5 minutes of trying to get it started my RX-8 came to life. Thank you all for your help and ideas.

 

So, ah, what sensor were you unplugging?
Its not like there are a whole slew of other plugs next to the crank pulley.

 

I was unplugging the ac compressor... whoops. I did this because after looking at the engine crank no start service bulletin i was basing what i was doing on the sketch of the sensor. Once i saw i actual picture of the plug i double check what i was doing and i realized my mistake.