I stopped at a gas station to refuel, when I started my car back up it would crank but not ignite like it has in the past when my engine flooded. I did my typical crank for 10 seconds then rest then crank with foot on the pedal then rest and what not to get it started. Eventually cranking the engine wore out the battery and it died, inevitably. Got someone at the gas station to give me a jump to recharge the battery and car started right up, as if the engine had never flooded. All was well, until on my way home in 4th gear I had a sudden, obvious, loss in power and a very strange vibration, coupled with a flashing CEL. From what I've read, this was a misfire. It lasted a few seconds then returned to normal, this was the first misfire I've had since I've owned my car. Could this be bad coils/plugs/wires, or signs of engine failure? I'm currently at 84,000 miles and I have noticed a slight power loss since I got my car a year and a half ago. It has always had trouble starting while hot, but starts right up when cold. Any advice? Thanks.

 

Hot start troubles when it starts fine cold is pretty much the only symptom of compression loss that isn't shared by other problems.

If your ignition was the only problem, you would have just as much trouble cold as when hot, same with starter or battery failure.

Take it for a compression test. It has probably been failing for a while, since it has "always had trouble starting while hot". A good engine starts just as good hot as cold.

 

Hard hot starting only is classic sign of low compression.
Flooding is a sympton of an underlying problem, commonly failing ignition components.
Failing ignition kills cats.
Bad cats kill engines.
Get codes scanned & check cat first, IMHO.

 

Dagnabbit, I'm goin to stop now
RIWWP on top of it.
I type way too slow.

 

I have an update for you all, and not a good one:
I went to start my car this afternoon, and it would crank but not ignite, just like last night as described above. I got it jumped, again, and I let it idle to recharge the battery then it died, again. So I got it jumped, AGAIN, and kept my foot in the gas to keep it alive, and started driving it. Then one of my rotors goes out and I have no power. The car is making a horrible deep throaty noise and it's vibrating quite a bit. Sometimes the rotor would kick back in and it would be back to normal but then it would cut out again. I parked at the nearest place where I could leave my car overnight and as soon as I removed my foot from the gas pedal, it stalled out. The engine bay smells bad and the inside of my exhaust tips are coated in this green powder. It's weird, help?

 

what help are you looking for. It is becoming more and more clear that, as previously mentioned, you are shot on compression.

 

Compression isn't the only factor here. It sounds like bad ignition, because this morning when I went to start it it had trouble starting while cold. That's more of a sign of bad ignition than compression, but I am no expert. Which is why I am posting here..

 

Symptom: Harder to start when hot than when cold
Possible causes:
A) Compression failure (if the engine has trouble staying alive when hot, and stalls out at idle)
B) Fuel pump failure (if the engine shut off while under load, and when it does fire it fires up completely fine as if nothing is wrong)

Symptom: Harder to start when cold than when hot
Possible Causes:
A) Coolant seal failure allowing coolant to collect in the housing, fouling the plugs attempt to fire on start
B) Weak battery (just weak enough that cold drops the cranking amps just enough to cause problems)
C) Fuel system pressure leak (takes time to rebuild pressure)

Symptom: Equally hard to start when hot as when cold
Possible Causes:
A) Ignition Failure
B) Starter Dying
C) Battery Dying


What does this tell you?


There are more symptoms of compression failure that you are giving us on top of this.

 

I'm putting my bets on ignition failure. Lord knows how old the coils plugs and wires are. But if it is indeed low compression, then a compression test would be first priority over new ignition? Can a compression test be done on it even though it will only start if its jumped, and once it does start it only runs on one rotor? The other interesting thing is, when it misfired last night I got a flashing CEL, which is normal for a misfire. But when I was driving it today the same misfire feeling had happened only it kept going and wouldn't return to normal, but no CEL? I really appreciate the help, either way its gonna need to be towed because I don't want to do anymore damage to the engine/cat with it only running on one rotor.

 

The priority is going to depend on what you want out of the car if it fails the compression test.

If you would junk it or sell it as is, then do the compression test first.

If you would keep the car anyway and deal with an engine replacement, then the ignition would need to be replaced anyway, so might as well do that first.

Compression test is done with the starter, and without any plugs or attempt to fire them. You can do a compression test on an engine sitting on a bench if you could figure out how to anchor a starter to it.

The ECU's misfire logic is anything but perfect, and the worse an engine is, the harder it is for the ECU to detect a misfire. Even then, not every misfire will flash the CEL. Attach an OBD2 reader and pull the system tests. One of the stored values is the misfire count. I bet it's through the roof.

 

An engine rebuild would be the likely outcome of low compression, so I will definitely go for a new ignition system, as well as new battery and new starter. I believe there's a place in Knoxville, TN that rebuild rotaries, which is only a couple hours away if it comes to that. Anyway thanks for your help!

 

Just a quick note, I did start her up perfectly fine no problems with the engine cold.

 

Here's a video showing the issue at hand. It had trouble starting while cold, but would not start at all when hot. Here's what it looks/sounds like when it does start. It felt like it was only using one rotor for power. It sounds like a lawn mower and died at idle.

 

Still the same diagnosis.

 

Got the car towed to mazda, did a compression test and got the following numbers:
Front rotor: 6.8, 6.8, 6.9 @250 rpm
Rear Rotor: 6.8, 6.9, 7.0 @250 rpm

He said compression is bad but wasn't the problem. The problem was the ignition, it is very very old and the engine is very very flooded. In you all's opinions, what do you think of those compression readings?

 

"He said compression is bad but wasn't the problem"

um.... a failing engine is certainly a problem and CAN indeed cause all these problems. A dead ignition is just adding further difficulty.


You just have 2 major problems, dead engine and dead ignition. Entirely possible your dead engine killed your ignition.

That engine very well may be reasonably rebuildable, give Rotary Resurrection a call. I've only rarely seen a dead engine that was THAT even between front and rear rotors.