Fellow R53'rs, I could use some help. After almost a yr of daily driving the R53, she finally had an issue on the freeway. As I do every morning, I warmed her up, let the fluids properly move around, and jumped on the freeway. After 18 miles, she hesitated when I tried to pass a car. I pulled over, checked for any leaks, popped-off hoses, etc. Nothing. So I jumped back on the freeway, hoping to limp it back home...nope, she couldn't make it up the hill. Symptoms include the following:

- hesitation/no throttle response after 1200rpm
- fuel consumption is uber poor (14mpg on the freeway)
- when throttle is engaged, s/c can be heard but the motor has no power
- after shutting down motor, it will not turn over

Side notes:
- The car has approx. half tank of fuel (91)
- Prior to shutting down motor, idle was at 1k rpm
- Was not racing, or pushing the motor
- Do not smell fuel
- Ran codes with OBDII reader, no codes
- Battery, ign. wires, plugs, air filter, bov, intake sleeves, etc. all new (within 1 yr.)


Could it simply be a fuel sending issue? Injectors or fuel filter?? Maybe a camshaft sensor?? Arghhhh. Any help would be appreciated.

 

Since it won't turn over it sounds like an electrical issue. My guess would be the alternator died.

 

I was thinking the same thing for a bit, but no lights came on at all. No codes, no hesitation on crank. It just wont turn over at all. Plus, I dont hear a fuel pump click when the ignition is engaged. Could a fuel pump relay fail while driving at freeway speeds?

 

I don't think a bad fuel pump relay would keep it from turning over, I don't know for sure, but it's not a very common thing to stop working either way. A bad fuel pump won't make the car not turn over.

Easy thing to do is just check the battery. If it's low, jump it or charge it and then try and start the car again.

Outside of my knowledge if it's not related to the battery or alternator. Good luck! Hopefully it's something simple.

 

Had similar symptoms when my harmonic balancer went. Worth a check.

 

The lack of codes makes me think the ignition coil is bad....check it for corrosion?
Harmonic balancer/crank pulley usually results in a bunch...a bad coil might give you a notice, but might not...
Failures tend to be heat related....

 

If the car doesn't turn over you either need to look into power supply, generation, or signal. Loss of fuel pressure or spark won't keep the car from cranking, but they will keep it from starting.

So is the car actually cranking and not starting, or is it not cranking at all?

If the car cranks and doesn't start and you say there is no fuel pump prime at key on I would start with diagnosing the fuel pump.

 

Had something similar happen to me. Turned out to be the electronic throttle body.

 

Updates:
The car wouldnt turn over at all, originally. Then I changed the fuel filter and pump (it was basically chocolate milk in the filter housing), and she started right up. The power seems to be lacking, and the hesitation is light, yet noticeable.

ZippyNH, you may be on to something with the coil, since it continues to slightly hesitate in the afternoons, but not so much during the morning commute. The harmonic balance, battery, ignition wires and plugs (just to name a few items) are no older than a yr and a half. I'll definitely look at the ignition coil.

 

Correction: I have a bad tendency of using 'turn over', 'crank', and 'start' too freely. The car would turn over/crank but the motor wouldnt start. After replacing the fuel pump and filter, it started with ease. Please excuse my buffoonery, it's a bad habit.