rb wont rev past 2k

[kmcmachinegun]

rb25det s1 wont rev past 2k, the highest i could hit according to safc was 2505 rpm

the car wouldnt start after it got hot then alternator died
changed bad wiring on coil packs to new, new alternator, plugs

before when it wouldnt start hot it ran perfect

ideas?

[kmcmachinegun]

the car starts up and idles just fine
after about 2-2200 it gets real choppy like its hitting the rev limiter

[Sileighty_85]

check coolant temp sensor and MAFS
Make sure you got the correct MAFS

[kmcmachinegun]

i just changes temp sensor
it has to be the correct mafs it was flawless for over 4000 miles

is it possible for the mafs just to go bad without any warning

[Sileighty_85]

check ecu for codes and try cleaning the MAFS

[kmcmachinegun]

how do i check the ecu for codes?

[Sileighty_85]

On the ECU you should see two holes on the side, One with a potentiometer and another with an LED Light

- to set car into diag. mode, with the key in the "ON" position, turn potentiometer screw on ECU fully clockwise, Wait for 2 seconds, then turn it fully counterclockwise. The LED on the ECU will begin to flash.
- first digit = LONG blink; second digit = SHORT blink (ex: 1... 1... 1... 1... then 1-1-1 equals 43 = TPS)


11 Crankshaft position sensor
12 MAF sensor circuit (air flow meter)
13 Coolant temperature circuit
14 Vehicle speed sensor circuit
21 Ignition circuit
31 ECU (ouch!)
34 Knock sensor
43 Throttle position circuit
45 Injector leak
51 Ignition circuit
54 Auto signal to ECU
55 All OK

[kmcmachinegun]

ill try it, thanks for the info

[ghost_22_47]

Just so you know, becuase noone said anything previously. This is called LIMP mode. It's a factory default setting for the ECU when something is wrong and could damage the engine. MAF's could be dirty of the wiring could be grounded out or there could be many things but checking the ECU should most deffinitly tell you where to start looking. Good Luck

[Pandapants]

31 ECU (ouch!)


Bahahahahaha

[kmcmachinegun]

okay so i cleaned my mafs and replaced my shitty air filter
no results

i tried the getting the ecu to flash but it turns out there is no potentiometer or led
is there any way out of LIMP mode or am i basically fucked here?

like i said before i ran this exact setup for a few months without issues

[kmcmachinegun]

the rb will start hot now, changing the temp sensor def made a difference, still only revs to 2k

[Sileighty_85]

Check the MAFS per FSM or borrow someone else's

[Couped_up'd]

Ya, it should be your maf bro.

[kmcmachinegun]

borrow someone elses maf? hahaha no one in this area even know what a rb25 is let alone has one - see where im from weedville, yeah its out there. the road i live on is dirt and ive daily drove 240s for the last 4 years often low as hell and full kits. still everyone asks what kind of car that is

z32 wont work either will it?

[kmcmachinegun]

how can all this happen at once, bad wiring somewhere?
alternator died
bad temp sensor
mafs

[Sileighty_85]

Z32 will only work if you use an SAFC (not reccomended)

RB20's use the same MAFS as the RB25 S1

Check all piping as well


Maybe the ALT Spiked before it died and thos sensors just gave way.

I would go over your wiring to make sure noting is grounding out or shorting.

[GabeS14]

Very simple pointer here:
Check your intercooler piping! first, before all the rest..this is if you have not already.
it would give the same symptoms as a bad maf. sound like a subaru and not rev past 2-3k.
it's worth it to rule it out and if that's the issue, itll save you $$.
another thing to check would be the coil packs.

[kmcmachinegun]

okay, my wiring is so bad, i have a new rb into s13 harness coming
yury said it wont be here for at least another month

i have safc but i only use it for an accurate tach reading and i do have 2 z32's laying around but im not about to chop up my already ridiculous wiring, whoever did the wiring for the original swap knew what they were doing and did it in a hurry the tape is falling off everywhere and is just a complete train wreck

i literally have wires and plugs sticking out everywhere not wired to anything, i dont like running it like this but no harness has came yet

[kmcmachinegun]

i did check all the ic piping and even the bolts on the manifolds as well as the turbo

im also pretty sure that i dont have a vacuum leak the only place could be bov but the hose still looks decent

[Sileighty_85]

Id check the Voltage comming out of the MAFS plug

[kmcmachinegun]

im waiting right now for dad to get home from work so i can bum his volt meter, ill let u know how i make out

[GabeS14]

i did check all the ic piping and even the bolts on the manifolds as well as the turbo

im also pretty sure that i dont have a vacuum leak the only place could be bov but the hose still looks decent

Ok , what about the Coil packs..? I just stress those two because they are the most common. Iv'e had the same issue about 6 times, and everyone always though MAF but it ended up being coilpacks and loose intercooler couplings

[kmcmachinegun]

well i just had the coil packs out, their wiring completely shot and all the plugs were falling the apart, i changed that part of the harness from the ignitor out

i also cleaned all of em while they were out and taped them up
i didnt see any cracks, not saying thats fool proof either

[drift213]

weedville

i want to live there :D :ssex: or weed town dont matter i just want the weed hehehe

[kmcmachinegun]

its right next to byrndale and both are in jay township
its so bad no one could make that up

[kmcmachinegun]

anyways i have no power to the mafs and found a wire that used to be spliced into my coil pack harness on the white and red wire

is this for power?
where should it be?

[kmcmachinegun]

well shes runnin , gotta go clean up the wires and take her for a ride in the snow!

[GabeS14]

well shes runnin , gotta go clean up the wires and take her for a ride in the snow!

So it was the Coilpacks?

[jtmny1999]

what was it? sounds like the MAF