Engine quits
 

I was at the track this weekend and while running at about 6000 to 6500 RPM as the car is transsioning back to the opposite G load the engine seems to quit running. I turned the key off then back on and it starts like it never missed a beat. No code of any type on durametric.

Is this the fuel pump filter or the knock sensors. I can't find any info on this happening to anyone else.

Stupid question, if you disconnect a battery pole... will the boxster car still run off the alternator?

Battery rocking in its tray/loose pole?

Just a guess mate, I have no idea what would cause something like that. Pretty weird in fact

How much fuel did you have in the tank?
Sound like the fuel delivery got interrupted during the transition.....
Or could you have hit the rev limiter by mistake.

Work performed on the car prior to this event.
1. Removed the power steering pump and replaced due to tapping sound from idle to about 2000 RPM.
2. Wevo front motor mount because of cracking another stock mount.
3. 997 split control arms on rear
4. 996 rear adjustable toe links
5. 4 wheel alignment

I don't enter track with less than a 1/2 tank of fuel
I run Track Data the blip shows up on the recorder at 6000 to 6500 rpm if the G load was at least 1 G load and reverses to .5 or higher to the opposite side. The first time the car would not pull and I went into a runoff area, after an entire straight. Turned the key off turned the key on Full power back to pit. I ran two programs of diagnostic. The fuel trims were all normal no codes. The next time as fast a I could reach the key and turn off to on I had power

Do Knock sensors cause a code or reduce power. This was one suggestion I got.

Do you have any lights/codes coming up?

I would check wiring harness. Possible something gets yanked around and
freaks out the computer.

Mike

Knock sensors only retard the timing

Test fuel pressure. I mean with a gauge attached to the fuel rail. You already did the toughest test, on track at high rpm & it may have failed that test.

I can't remember seeing any dash lights until after switching the key off and back on. Dura metrics showed no code on computer. Dyno Scan another performance scanning tool that does support the Boxster 2000 to 2005 codes and diagnostic showed no code current or stored.

The first time really freaked me out I was thinking the engine blew no real noise no vibration. I was passing a flag station and no yellow came out so I wasn't dropping anything or smoking. I looked at the shifter and took it out of 4th and back in nothing. Clutched in with gas it didn't rev. I looked behind for smoke. I left the clutch back out and the engine spun with out vibration. I passed second flag station no flag include black or meatball still pull into the pass through area off line. I stopped turned off the ignition, turn on the ignition it started like nothing happened. All the normal lights came on then went out. I revved the motor several time it sounded perfect as before. Popped it into gear and drove to the pits. The next session after 5 laps the same place within 30 feet. I reached over turned off the ignition turned it back on and hit the gas. Off we went dropped maybe 5 MPH in the process.

The rest of the day I lifted about 10% before that transmission. Sunday I was hitting the area at about 10 mph faster so I just shifted 4th to 5th and kept in the throttle about a 1000 RPM drop.

Two other times in another left turn right turn situation the same thing happened.

Are all your grounds tight and corrosion free?

I yes they are all tight no corrosion any place in body. The car has always been garage kept and rarely drive in the wet. Checked all control module plugs were tight (latched) the first time this happened and looked at all the trunk grounds.

Does your RPM go to zero when you lose your power (even though the engine is still turning?) If so then Crank position sensor. When that fails you won't get any spark.

We had something similar on our 944 race car, but it didn't require a restart.
Engine would cut in and out. Tach would drop to 0 then wake back up,
rinse and repeat. Was a challenge to drive.

Turned out to be an overheating ECU.

Mike

I started looking at the data recorder. The RPM just go flat and start to drop as I slow until I hit the clutch and turn off the key where it drops sharply then as the key goes back on the rpm raise again. The data recorded is tied to a common point for the Tach. So although I don't remember seeing it drop the data recorder would say it did not drop out.