LS2 dies sometimes high rpm, no power

[Gummisko]

doing this for a friend.

LS2:
228r cam + supporting mods
sikky LT headers

started tuning. but ran into problems,first i cant rev it past 4000rpm

tried exchanging the MAF = no difference
removed maf= revs high
changed the old maf back = it revs high but no power...?
feels slower than with oem cam...=(

"idle engine dies" = is before we started exchanging maf, long time idle then we rev it and it dies...
"revving utan maf" = rev without maf
"short drive" = old maf in again

fixed tune will be rewarded, i have paypal.



///

[schpenxel]

Has it always done this or just started suddenly? Before/after mods?

[schpenxel]

Are you sure there isn't an exhaust leak? Those FT and O2 readings are all over the place. You need to get a wideband on it IMO. Very least it needs some serious VE/MAF table work.

I don't understand what you mean by can't rev it past 4K when the logs show you revving it to over 6500?

Idle spark tables also look to have some pretty abrupt changes from 600 to 800 RPM's too. Just start with the stock table and raise the whole thing 5-6*

[Gummisko]

all this is after cam install...

it is being tuned by a tuner but he is not so familiar with hp tuners,
and he was wondering why it dies at WOT over 4k rev, he has never experienced anything like it...there are no saved log of these runs....

he tuned my car with a similar cam (comp xer281) and no problems...

(im just the middle man with all the hp-tuners hardware)

first as soon as it got over 4000 it died, several times only have one log when it dies, the "idle engine dies" at the end....
but after fiddling around with diffrent maf it did finally rev over 4k but no power

[smokestack]

Sounds like you need a new tuner. You already stated you have PayPal. This is a forum for help working on your own learning experience.. Not really one to pay for help. So im not sure what else everyone will be able to help with if your just a middle man...........

[schpenxel]

all this is after cam install...

it is being tuned by a tuner but he is not so familiar with hp tuners,
and he was wondering why it dies at WOT over 4k rev, he has never experienced anything like it...there are no saved log of these runs....

he tuned my car with a similar cam (comp xer281) and no problems...

(im just the middle man with all the hp-tuners hardware)

first as soon as it got over 4000 it died, several times only have one log when it dies, the "idle engine dies" at the end....
but after fiddling around with diffrent maf it did finally rev over 4k but no power

You need a new tuner. I'm sorry, but if he isn't used to HPT, what is he used to? Let him use that instead. You can read/change the tune in HPT afterwards.

You also need a wideband on it. My bet is it's either so ridiculously lean or so rich that its not making any power and that's why it had problems revving.

Get this thing to someone that knows what they're doing before he starts breaking parts.

[schpenxel]

Based on "short drive" log it's going leaner than 14.7 @ WOT in several spots based on the narrowband O2 readings.

Like I said.. need a wideband before this bozo blows something up. Do not keep driving it like this.

Also you aren't logging knock retard so it very well may be knocking on top of being this lean.

[Gummisko]

i contacted my friend today again and he had found a blown fuse, now it pulls strong again... will make new logs

where to start error search on the knock sensor?

the tuner we are using is very experienced with VEMS and other similar aftermarket systems
my car was the first time he used hp tuners, and this one is the 2.nd one

[schpenxel]

Tuning VEMS and aftermarket systems is NOT the same as tuning GM systems. Aftermarket systems have wideband O2 sensors so you can literally just set the WOT AFR you want and it'll do it. GM doesn't have that type of O2 sensors, so you have to manually adjust airflow tables to make the actual AFR match commanded. You cannot do that without a wideband o2 sensor.

Add knock retard to the list of channels you're logging and it'll log it next time

I'd like to see a log after this blown fuse was fixed to see how things changed, if you are able to post one.

[GHuggins]

Curious - what fuse was replaced?

[Gummisko]

yes he knows its vey different to aftermarket,

i cannot log wideband with my version of hp tuners MPVI (i regret buying the standard version)

i dont know if the fuse had something to do with it because my friend also rearranged some wiring... maybe a bad connections some where?
it was the cig lighter fuse? maybe the custom loom takes power from that fuse? or just an strange coincident
the car is a ls swaped nissan 240sx s13.

[Gummisko]

suddenly it works...

we have battery problems, will get replaced asap
and iat is too high will sort thar with heat shield.

could the above cause cutouts at high rpm?