z4 dies only on the track

[jon1275]

I am wondering if any others on the forum have had similar experience??? This happened 4x this past weekend at Road Atlanta on a track day. It has happened 3x total over the past 6mos on track days--so the 4 episodes this weekend much worse. So what happens is that when under load, power will be lost and I will coast to a halt. When I put in clutch the engine dies out. All electrical systems seem okay with no fading or pulse. The car will then immediately start right up and run fine until the next time. This has happened under full throttle, high rpms, and most occasions high g load. I have no codes coming up other than the emissions sensors which have been up since I pulled my cats off. This also didn't happen until I added the ESS tune (?coincidence). My best bet is a fuel delivery problem with either the filter or fuel pump (gas tank has been full when this occurred). I don't drive the car much on the road but cannot duplicate under normal driving. My plan is to replace fuel filter and then if this fails the fuel pump. Any other ideas would be much appreciated? thanks, jon

[ZStig]

Ess supercharged cars have similar issues at tracks.

[Gt4]

Check this thread:

http://www.zpost.com/forums/showthread.php?t=871393

[3002 tii]

Definitely not a coincidence

[gmd2003]

Originally Posted by jon1275

I am wondering if any others on the forum have had similar experience??? This happened 4x this past weekend at Road Atlanta on a track day. It has happened 3x total over the past 6mos on track days--so the 4 episodes this weekend much worse. So what happens is that when under load, power will be lost and I will coast to a halt. When I put in clutch the engine dies out. All electrical systems seem okay with no fading or pulse. The car will then immediately start right up and run fine until the next time. This has happened under full throttle, high rpms, and most occasions high g load. I have no codes coming up other than the emissions sensors which have been up since I pulled my cats off. This also didn't happen until I added the ESS tune (?coincidence). My best bet is a fuel delivery problem with either the filter or fuel pump (gas tank has been full when this occurred). I don't drive the car much on the road but cannot duplicate under normal driving. My plan is to replace fuel filter and then if this fails the fuel pump. Any other ideas would be much appreciated? thanks, jon

You are experiencing the ECU going into a safe mode which can happen for multiple reasons . It is not fuel starvation , especially if you are NA with a full tank . The most common reason in both a NA and FI car is temp related , both water and oil temps can cause it . In FI cars we also have a problem with the ECU seeing boost in the vacuum system . What are your oil and water temps on track ? I'd figure that out first .
George

[Str8 RippiN]

Has to be the Tune had the same thing happening to a bunch of ESS supercharged Z's

[Finnegan]

Originally Posted by Str8 RippiN

Has to be the Tune had the same thing happening to a bunch of ESS supercharged Z's

Interesting hypothesis! Especially since there were no issues before the tune. That's a pretty strong link.

[Beedub]

yup and ess keep saying their coming back to us with answers at least.... and as usual nothing...... the only saving grace is i havent had this limp mode yet.... however when the spring arrives ill be doing some testing on a much larger track than my usual local sprint circuit....

[jon1275]

Originally Posted by gmd2003

You are experiencing the ECU going into a safe mode which can happen for multiple reasons . It is not fuel starvation , especially if you are NA with a full tank . The most common reason in both a NA and FI car is temp related , both water and oil temps can cause it . In FI cars we also have a problem with the ECU seeing boost in the vacuum system . What are your oil and water temps on track ? I'd figure that out first .
George

This is good info. I didn't know there was a safe mode. Doesn't feel safe stalling at over 100 mph though! I don't have separate oil pressure/temp gauges but running temp doesn't push past the center (250-260 I think). Yes, am running full tank with NA setup. Having some extra gauges is on my car wish list though. Since was happening under high G load I was wondering if the motor was experiencing a low oil pressure? I have a call into ESS to see what they think. -jon

[jon1275]

Spoke to Roman, who kindly called me right back--he thinks that could be either oil temp or brake vacuum assist triggering a safe mode shutdown. The brake issue should trigger a code but the oil temp will not but says than generic scanner (like the one I own) won't show "hidden codes" like the brake issue. He recommends getting ecu scanned with dealer and then follow-up.

[gmd2003]

Originally Posted by jon1275

Spoke to Roman, who kindly called me right back--he thinks that could be either oil temp or brake vacuum assist triggering a safe mode shutdown. The brake issue should trigger a code but the oil temp will not but says than generic scanner (like the one I own) won't show "hidden codes" like the brake issue. He recommends getting ecu scanned with dealer and then follow-up.

If your hitting 260 oil temps then that is a big factor probably causing yours 80% of the time . Since I've gotten my oil temps to max in the 230 range my number of limps has been reduced 80%
George