There is somekind of problem with my car that I couldn't adress why. At the high rpms (actually after 6000) the car hesitates badly. It feels like rev limiter but it isnt. When I rev the car at idle there is no problem but when i rev it @ boost like 8-9 psi, it has hard times reving after 6000 rpms.

A mechanic i spoke to told that it could be because of either of the reasons below:
1) Valve spring problem
2) Insufficient spark

Here is a log of the car while this happens tough I couldn't see anything wrong in the log.

I'm running UTEC w speed density enabled.

Any ideas why these things are happening?

I also got a P0011 cam sensor CEL constantly from the day my engine was built.



6016 +8.3 5.00 100 70 00 W/B 67 +27.8 63.7 +19.5 +2.0 3.98 11.93
6060 +8.3 5.00 100 70 00 W/B 68 +28.5 64.1 +19.4 +2.0 3.98 11.42
6060 +8.3 5.00 100 70 00 W/B 68 +28.6 64.7 +19.4 +2.0 3.98 10.93
6049 +8.4 5.00 100 70 00 W/B 70 +28.6 64.4 +19.4 +2.0 3.98 10.64
6127 +8.4 5.00 100 70 00 W/B 76 +28.7 54.1 +19.3 +2.0 3.98 10.64
6116 +8.6 5.00 100 70 00 W/B 71 +28.7 64.1 +19.4 +2.0 3.98 10.73
6242 +8.3 5.00 100 70 00 W/B 80 +29.4 65.7 +19.2 +2.0 3.98 10.87
6150 +8.5 5.00 100 70 00 W/B 80 +29.4 66.5 +19.2 +2.0 3.98 10.96
6172 +8.6 5.00 100 70 00 W/B 78 +28.9 65.7 +19.1 +2.0 3.98 11.02
6218 +8.3 5.00 100 70 00 W/B 85 +29.3 66.4 +19.1 +2.0 3.98 11.12
6172 +8.7 5.00 100 70 00 W/B 84 +29.4 66.7 +19.0 +2.0 3.98 11.11
6265 +8.7 5.00 90 70 00 W/B 85 +29.4 66.2 +19.1 +2.0 3.98 11.02

 

what is it like? does the car keep reving but you loose all power to the wheels?

 

spark plugs

 

What do you have the rev limiter set to on the Utec?

 

the car keeps reving but feels like misfiring madly.

 

......

 

sorry didn't see that, it's set @ 7200

 

Ok I was asking because we have seen that the Utec cuts the revs actually about 200-300 RPMS lower than what we set the limit to, but at 7200 that should not be an issue at 6200.

As mentioned it might the plugs, check their condition and gap, I assume they are colder plugs as well.

 

i had the same issue.. let me know when you figure it out.. i suspect utec but who knows

 

Also having same issue, but its lower. Mine happens around 5000 - 5500 rpm and only under WOT. If I ease through the problem area and then get back on it right before redline everything is fine. Gonna take it back to SGP again this week - might try the plugs... I ran extra rich on mine for awhile.

 

yes they are HKS 1 step colder plugs. I've also seen that rev limiter cuts earlier then it's supposed to in UTEC so i pushed it up to 7200 to ensure i can rev 6900.

I'll check on the plugs tomorrow and report.

 

colder plugs are very sensetive about rich conditions etc so u better check on them soon

 

Is this the issue cased by not having a ground on your UTEC? Where alot of power is lost at high rpm?

 

this is exactly how it was for me

 

mine was doing the same, it felt like the clutch was slipping kinda. mine did it in high rpms when i would shift and let off the clutch and give it gas, it would stutter about 5 times then kick in.

 

Spark blowout of some sort. re-gap plugs, check coils etc.

 

What's that issue? U got a link for that? We used to have a grounding wire for UTEC in subbies. I guess the Z-UTEC is grounded via oem ecu.


looks like i wont be able to leave work early today

i'll check the coils and plugs tomorrow. Thanks a lot for the tips and ideas everyone!

 

https://my350z.com/forum/tuning/198449-350z-utec-comments-from-turboxs.html

......

my guess is still spark plugs

 

ok thanks for the link i'll see how it comes out tomorrow.

 

ohhhh snap!!!!!!!!! that link explains it all