rb25 no power when warm

[uhhh-s13 again]

so ive had my swap done now for about 2 months into s13(bought from a friend was running and driving with no problems). put it in got it running, ran like crap knock sensor was unplugget and I put new plugs in, fixed ran awesome. the biggest plug gap I can run is .026 or it cuts out maybe that normal but that seems kinda small to me coming from sr to 1j and now rb(should have stuck the 1j). that was an sc300 though. anyways my car kept going into limp mode like I had a bad maf and it would fix itself on its own, it never does that anymore though.

now after it warms up it has vary noticeable power loss and it even sounds different, like its pulling timing or something.
things I have done
was throwing code 13 got a new coolant temp sensor didn't change
checked voltage at ecu for knock sensors they were both 2.5v at idle
set tps and made sure it was correct when set while wot and closed
boost leaked checked multiple times and its solid
haven't messed with bov still recirc
tried 2 different fpr's and new z32 fuel filter
put extra grounds from block to chassi and an extra ground on coil pack harness
checked voltage at fuel pump 12 volts
when I put the motor in the timing was set at 20 degrees according to how you look at it rb's its kinda weird depending on the angle you look at while timing it. it had been that way for a few years with no problems im timing by putting my timing light on the white wire at number 1 coil with the timing light hooked up to a jump box for power because my battery is in the trunk. maybe that's all no good and need to make a wire from the coil to the spark plug and use that to time it?

now after about a week it throws coolant temp code again, so I ohm the wiring between sensor and ecu and I doesn't say offline but it reeds o.o ohms. I check the ground and its 3. something.

info about the swap
s1 rb25 mostly stock
I think its an older wiring specialties harness but its a little old now
hks actuator set to 9 psi
n1 thermostat
walbro
pulled from my friends running s13 and about 3 weeks later running in mine
pumped all old gas out of my shell and put new premium in
cx racing front mount
3 inch dp and exhaust

I don't mean to ramble on to run so good and strong sounds good while its warming up, and I don't mean dead cold and romp on it I wait till needle starts to rise on temp and pulls hard all the way to redline, then temp gets halfway up and gets slower and slower till it sounds way different and feels like has no boost just a na motor, still drives smooth though doesn't cut out and super rich. I don't have a wideband but it uses tons of fuel and backfires a little usually when I take my foot off the gas and start coasting.

ive tried everything I can think of and before I rewire my coolant temp sensor to the ecu I figured I would ask. ive been working on this for about a month now

[uhhh-s13 again]

one other weird thing is I hooked up a safc because I wanted to look at timing while driving(which it got late and I didn't hook that wire up lol), but the rpms on the safc are off from my cluster. a few hundred off at idle and as rpms go up it gets more and more off. maybe I hooked it up wrong but I don't think so maybe someone has had this problem.

I have my check engine light hooked up to the cluster because my ecu has no light on it, its been blinking while driving, not a sequence random, on the throttle it comes on, off it goes away sometimes, sometimes it just lit up and sometimes it blinks about a second apart. weird

sorry to drop a bomb guys lol. I know its a lot to read just trying to be specific
uhhh-s13 again is online now Report Post

[uhhh-s13 again]

Now it bad all the time even cold, still pretty smooth it's cutting and choppy, just no power. As soon as you go over about 1/4 throttle it feels like something is holding it back

[USMCgetsome]

your symptoms describe a slowly dying maf or serious vacuum leak.
Are you sure your using the proper coolant temp sensor?

Over all I believe it's the maf. Find a buddy to swap in and show us a pic of your engine bay. I've seen people put the maf right on top of the turbo inlet causing problems.

Reasons I think it's the maf. It slowly die's after it gets to normal operating and will lose power and then as you come to a stop it just falls dead. You'll do a restart and it will start but then die shortly there after again. Also, it eventually will just stop operating completely when starting days later.

Don't believe me look up my post on this matter. Happened to me years ago!

[uhhh-s13 again]

I tried my friends rb20 maf and it was no different. I checked my coolant temp sensor the new one I got about a week ago and it was bad. Got a new one ohms were at 2.9 cold brand you the other was 0.0 hot or cold. And now I'm throwing a knock sensor code. I reset the cores drove it home I made it about 20 feet ad check engine light starts blinking again, random blinks I have video if you want. So tomorrow I'll check the ohms on the new coolant temp sensor and see if it is bad already. Not sure why it be getting fried I checked the wiring it's all good. Maybe my ecu is bad? Here's a pic my maf planet far from the turbo in a good spot and solid.

[USMCgetsome]

hmmmm..... Next on the list is FUEL PUMP and gotta see if coil igniter is in ok shape.

[uhhh-s13 again]

Ya I do need to check the igniter. I was arching into the head on every coil pack I could see it at night so I put dialectic grease in the boots and it fixed that. I was having cut out issues and I had to run a smaller plug gap down .026 with new plugs or it would cut out after about 4 thousand Rpm's. The fuel pump is a walbro about a year old it does sound a little weak sometimes when I prime it. It runs rich though. I got about 150 miles out of a full tank of gas. Mostly in town driving but still that's terrible.

My friends car the other one in the pic is down maybe I'll steal his walbro and put it in my car for a test drive. And borrow my other friends igniter. Pretty sure rb20 igniter is the same

[USMCgetsome]

WARNING!!! if removing the fuel pump make sure battery is disconnected and also ensure your wearing an esd strap and no clothing that would cause esd to occur. I know it sounds dumb but man you'd be surprised what a bomb that tank will turn into.

yep the igniter chips are swappable if they look the same. iirc there are some variants of the chips.

GOOD LUCK MAN! also you need to look at LIQUID TAPING the bottom of your coil packs. There was a thread long ago about leaking coil packs igniting to the block.

[uhhh-s13 again]

Ya I was thinking about doing that I've read that post. So that worked pretty good with coil packs?

Tidally random my car drove great all the way to breakfast I even clutch kicked second and it spin tires no problem like it should, I turned my heater on and then it started running bad again. Weird probably not connected just funny timing

[USMCgetsome]

you sure your coolant was filled properly? Could be the coolant temp sensor lost coolant and couldn't read properly. run a few more times with heater off beat on it(gas pedal) spirited driving and see how she is idling. iacv as well?

[uhhh-s13 again]

I don't have an overflow tank and I found out my heater core hose leaks pressure and a little coolant but I can hear it bleeding off

[USMCgetsome]

HEATER CORE BYPASS!!!!!!

[uhhh-s13 again]

Or new heater hose. It's winter here in oregon lol

[USMCgetsome]

lol I forget about your winter storms. It's raining down here in texas lol!

[uhhh-s13 again]

I have a friend stationed in Texas drives a 350z it would be funny if you knew him.

Anyways winter is almost over now I can't wait. Haven't had time to work on my car but rewiring te coolant temp sensor is next and fix heater core hose

[uhhh-s13 again]

So I figured it out, well for the most part. I had my vtc plug and coolant temp sensor for the ecu plugs switched lol. Same plug and the same area and I was told everything was correct. So I followed the wires back to the ecu and that's when I figured out they were backwards. So it runs way better but I got a knock sensor light still. Rb problems lol

[Darius]

I'm surprised those two plugs are interchangeable. The rest of the harness is idiot proof with the way the male and female plugs are designed.

[USMCgetsome]

GLAD YOUR UP AND RUNNING MAN!!!!!!!!