boxster cranks but won't start..help!!
 

My boxster cranks, but doesn't start. I've change the crankshaft/reference sensor twice and it does the same...The ECM tested good...Please help...What other sensors should I change or what else should I check?

Wish I could help, are you in the OKC area? I'd give Dumont's a call, 1-405-232-6497, and see what they say.

Start with the basics. Are you getting fuel, air, spark? What year and mileage?

crank, but won't start
 

Yes, I'm getting fuel, air and spark. She is a 1998 boxster with 113k miles... Last week I was driving down the highway approx 65 mph. I then push down on gas to go faster and all of a sudden it started jerking and popping like I had bad gas or something....I had to pull on the shoulder of the highway because I lost all the power in the car. I tried to start it back, but it would just crank and crank, but not turn over an start......What do you think?

crank, but won't start
 

Yes, I'm getting fuel, air and spark. She is a 1998 boxster with 113k miles... Last week I was driving down the highway approx 65 mph. I then push down on gas to go faster and all of a sudden it started jerking and popping like I had bad gas or something....I had to pull on the shoulder of the highway because I lost all the power in the car. I tried to start it back, but it would just crank and crank, but not turn over an start......What do you think?

Try disconnecting the plug from the Mass Airflow Sensor then try and start the engine, if she starts right up, replace the sensor. Also try to rent the ODBII SCANNER from Autozone and check for pcodes n post them here and we'll help yah out

I had a 99' which did the same thing, cluncked out on my on I-5 in San Diego, 5 hours from home. It would turned over, but would not start, it was the MAF. $600 later, it was fixed by the dealer. Since then I've fixed my own MAF's under $250, a very easy to DIY.

crank, but won't start
 

Okay, I just tried to unplug the mas sensor and start her, but she still did not crank over...I then rented a ODBII scanner and tested it. The codes I got are PO336 crankshaft sensor & PO727 engine speed sensor?

crank, but won't start
 

Okay, I just tried to unplug the mas sensor and start her, but she still did not crank over...I then rented a ODBII scanner and tested it. The codes I got are PO336 crankshaft sensor & PO727 engine speed sensor

Sounds like a mechanical timing issue to me.

Unfortunate for you if that is the case.

I wouldn't try to keep messing around cranking and turning it if I were you.

Get it to a dealer or a crack independent to find out what's really going on and hopefully that I'm wrong. good luck.

The DME isn't receiving a signal from the crank sensor. Either the sensor has failed, there is a wiring issue or your DME has failed. Also could be possible the flywheel has lost a significant portion of its teeth but that is pretty unlikely.

To test the sensor, disconnect it at the motor and measure across pins 1 &2, it should have 0.8-1.0 kohm resistance at around room temperature (20 C). Across 1 &3 it should be open. If not the sensor is bad.

If the sensor is OK you need to test the wiring between it and the DME.

-Todd

Leave it to a "Master" to come with a logical conclusion. My friend's 3.2 DME 911 died a similar death; culprit was the crank sensor.

You learn a lot from these boards; not that I can remember it, but it's always a great resource.