No power after 4k rpm help plz

[isthatguy]

Ok, first off, the mod list.
47# stage 3 turbo less thank 1k miles
ported manifold with DCR ramp mod
PTP wga 20psi
6 an returnline 43.5 rising rate 1:1
6 an feed line with bottle neck fix
walbro 255 fuel pump
fuel pump re-wire
RC750cc injectors
MSD 8.5 wires
NGK 1 step colder plugs (less than 200 miles)
stock pcm reflashed via DSP + turbo666
3bar map/tip
3" intake/ catless exhaust/o2 housing
Griffen BFMIC
ported intake manifold + throttle body
(i think thats all that matters)



ok the car drives perfect under normal driving, but under WOT as soon as 4krpm hits the car has no power, it still holds boost at 20psi a/f at about 11.6/7
it seems like it hits a wall, this just started, and the exhaust makes a CRAZY loud rattle noise as soon as the car loses power. (i will try to take a vid soon)
the car dynod at 347whp with no issues, this just started after I put the ported i/m t/b on.
what we have tried to diagnose/fix to solve this

put stock i/m t/b on - no fix
change wires - no fix
change plugs - no fix
regap plugs - no fix (gapped at 30 now)
change coil pack - no fix
Compression test:
Cyl 1: 145
Cyl 2: 150
Cyl 3: 150
Cyl 4: 150

then we decided to do a bottle neck fix and fuel pump rewire - no fix

we put the gauge for the fuel pressure on the windshield, the car is holding fuel pressure fine, and under wot is at like 63 (1:1) so everyhting with fuel seems ok, and the car is idling fine and throwing no CEL codes.

please help, we are lost

[HCCAFan]

Cat clogged up?

[isthatguy]

Quote: Originally Posted by HCCAFan

Cat clogged up?

edited first post, I am running a catless exhaust, only 1 resonator. exhaust is 1 year old, never seen winter.

[magego]

mmm, i used to have the same problem but my car was stock, i change the wastegate, and computer, and it fix it, i check whit the original ecu, but you can try whit the wastegate

[SrT4u2Nv4EvA]

Kinda weird mayne. Eric's car was doing this exact same thing.. but that was before he got fuel management... everything is fine now.. He is also catless.

[rasp]

Do you have the WOTbox/2-step?

[isthatguy]

Quote: Originally Posted by rasp

Do you have the WOTbox/2-step?

i do not.

the only electronics I have is an AEM wideband, and a electronic boost gauge.

I am thinking that maybe the PCM is pulling mad timing.

[rasp]

So the car pulls until 4k, then it falls on its face but still maintains 20 psi and a good A/F?

Are you using the DSP (thought you were; I may be wrong)? If so, log it.

[isthatguy]

Quote: Originally Posted by rasp

So the car pulls until 4k, then it falls on its face but still maintains 20 psi and a good A/F?

Are you using the DSP (thought you were; I may be wrong)? If so, log it.

yup, and I will log it tomorrow for sure

[isthatguy]

does anyone think this could be a TPS issue?

[AnotherNeon]

COT needs to be disabled i am guessing

[isthatguy]

Quote: Originally Posted by AnotherNeon

COT needs to be disabled i am guessing

COT ?

[ghice007]

Quote: Originally Posted by isthatguy

COT ?

Cat Over-Temp Protection....it uses your calculated egt and when it goes over like 16xx something it dumps fuel in to cool the cat. Eventhough you dont have one lol. Check with Turbo666 and see if he disabled COT in your tune.

Does it run fine if you take it past 4k when your not at WOT?

[Slow_spool]

Quote: Originally Posted by isthatguy

yup, and I will log it tomorrow for sure

ill take a look at a log when you post one

[isthatguy]

Quote: Originally Posted by ghice007

Cat Over-Temp Protection....it uses your calculated egt and when it goes over like 16xx something it dumps fuel in to cool the cat. Eventhough you dont have one lol. Check with Turbo666 and see if he disabled COT in your tune.

Does it run fine if you take it past 4k when your not at WOT?

yeah it drives normal over 4k if im not WOT..