I just got a new motor in the car about 300 miles ago. The other day I was driving, when I came up on a red light and the car shut off.

I went to start it, and when I did, it wouldn't start.

Eventually after 30 minutes, I went to start it again, and it started. I drove it home, and as soon as I came to a complete stop, it shut off again.

I've taken it to a mechanic, and they can't seem to find out the issue at all. They replaced parts in it seeing if that would do anything and it hasn't. The crank sensor, and coolant has been changed, nothing works.


Transmission: Automatic
Mileage: 92k... new motor was replaced about 300 miles ago.
Year: 2005

TL;DR: Basically the car just heats up quicker than normal, and when you put it in gear, it eventually shuts off.

Has anyone had this issue, and gotten it fixed before? Whats wrong with the car?

 

Yes, lots of people have. Take it to a dealer for a compression test. Stalling when hot, harder time starting when hot, and being able to start fine when it cools down = compression loss.

The only other common explanation is a fuel pump failure, however when it's a fuel pump problem the car usually cuts out while under load driving in gear, not down at idle, and it doesn't "stall", it just abruptly shuts off.

 

You didn't get a new engine, so who built installed your remanufactured engine?

 

I got it from Mazda.

Rebuilt or whatever, I had the choice of purchasing a new motor, or motor with like 60k miles on it, I went with the new motor.

 

The guys at the shop I have taken it to have been in business for years, and they have a good amount of knowledge on working with these cars.

I would assume they would know the basics about the rotary engine, considering the fact that they told me they worked on them before.

Like I said, they've replaced parts in it to see if it would fix the problem, and it has not. I'm sure the fuel pump was probably one of the first things they checked.

Any other suggestions?

 

Okay, so you got a Mazda reman. Did Mazda install it?

 

And don't assume anything, there are many things that could cause stalling.

 

Here are a few things that could cause stalling.

• Vacuum leakage
• Air leakage from intake-air system
• Air cleaner restriction
• Air suction at intake-air system (between MAF sensor and intake ports)
• Improper operation of drive-by-wire control system (abnormal accelerator position and TP signals to PCM)
• Throttle body malfunction (stuck close)
• Improper SSV operation
• Improper APV operation*
• Poor fuel quality
• Inadequate fuel pressure
• Fuel pump mechanical malfunction
• Fuel leakage from fuel injector
• Fuel injector clogging
• Fuel injector improper operation
• Fuel line restriction or clogging
• Pressure regulator (integrated in fuel pump unit) malfunction
• Intermittent open or short in fuel pump body circuit
• Fuel pump relay malfunction (stuck open)
• Restriction in exhaust system
• Purge solenoid valve malfunction
• Improper air/fuel ratio control
• MAF sensor improper installation
• Intermittent open or short of MAF sensor, TP sensor, APP sensor and VSS
• Erratic signal from eccentric shaft position sensor
• Improper ignition timing control (abnormal ECT, IAT, MAF and knock signals to PCM)
• Improper fuel injection control (abnormal MAF, ECT, and front/rear HO2S signals to PCM)
• Improper load signal (neutral/CPP switch (MT), TR switch (AT)) to PCM
• Main relay intermittent malfunction
• Low engine compression
– Engine internal malfunction
– Abnormal engine oil condition (viscosity, deterioration)
– Low oil pressure
– Excessive fuel pressure
– Air mixed in oil line
– Metering oil pump malfunction
• Leakage or clogging in oil pipe
• Leakage or clogging in oil nozzle
• Metering oil pump malfunction
• Improper metering oil pump control operation
• Engine overheating
• Spark leakage from high-tension leads
• Spark plug malfunction
• Improper A/C system operation
• Improper torque converter clutch control operation (AT)
• Improper shift point (AT)
• AT malfunction (AT)
• Clutch slippage (MT)

 

Whoops, missed the line of the recently replaced engine. Sorry.

 

No.

We ordered it from Mazda, and my mechanic company replaced it.

 

Oh well, it could be many things then, a simple vacuum cap missing could be the culprit. A reset of the NVRAM (search) might be in order as well but it needs to be troubleshooted properly really since it could be so many things.

 

This is great!

I will send my mechanic an email of this.

Thank you.

 

I think you should probably find a new mechanic.

 

+1 I always took it right to Mazda. May cost a little more but at least they have rotary techs.

 

I've only taken my car to the Mazda dealership once, and that was to have the motor rebuilt and only b/c carmax paid for it. If given the option I would have sent it elsewhere.

 

Negative, most Mazda dealer techs get very little rotary specific training, they are not even allowed to rebuild rotaries. We have a local guy who was a Mazda tech for years, owned and RX-8, and did dozens of RX-8 engine replacements and he used to call and ask us (none of us are real mechanics) questions all the time. Smart guy and a competent tech but rotary specific knowledge was limited since all they did was replace stuff, not really diagnose or fix things. But generally, yes they are better than normal mechanics who typically have zero rotary experience. And if you need diagnostic equipment (WDS, rotary specific compression test, reflashing, etc.) that only the dealer has well then of course that is the best option.