Om1krons Build thread cause I hate the lack of them! S14

[s13pignose]

Yeah I'm just throwing ideas out and what I find...funny thing is I just have a nearly stock ka. So a lot of this stuff is kinda new, but makes for good reading and maybe learning something new. Just really interested in what the problem is, cause I imagine it being quite frustrating

[lflkajfj12123]

trouble shooting is awesome -_-

[Bubbles]

Originally Posted by s0apgun

trouble shooting is fucking annoying

Nailed it.

[Enna]

Totally dude. Totally.

[codyace]

The car is reacting like one that would be in limp mode.

I know this sounds funny, but how is the diagnostic screw on the ECU itself? I've seen cars develop oddness like this when screws are half ass broken, or over adjusted etc etc. Part throttle all the way to redline, but unhappy when goosing it (just like your video)

Another thing to potentially check is the condition of the MAFS and the CAS itself. They are two other parts of the system that would trigger limp mode or similar symptoms (as will the coolant temp sensor, but that's unlikely in this instance). With so many SR cars, there is no way to swap and test?


It's not the BOV (if it wasn't strong enough you won't even make boost, maybe 1 to 2 psi) , I really doubt it's the pipes (plenty of cars with crappy welds run just fine), and I also doubt the O2 sensor difference(as when you go WOT it's ignored on a stock ECU, and just cruising around it's used...yours works fine cruising around).


These is the same harness and same components you've always had/used?

[Om1kron]

Originally Posted by codyace

The car is reacting like one that would be in limp mode.

I know this sounds funny, but how is the diagnostic screw on the ECU itself?

I've only turned it once to check the codes, it randomly threw the same codes it did before... water temp, knock sensor, and maf when my fuel pump died. I turned the car off and turned it back on and the codes went away. (Threw a 55) As you can see in the video water temp to the cluster itself doesn't work, but neither do the odometer and the other little 4 number indacator that I am putting mileage on it.

I do believe this cluster has been tampered with. But again that's not a problem because the temp sensor for the ecu is completely separate. And I've put a new one on the car.

I've seen cars develop oddness like this when screws are half ass broken, or over adjusted etc etc. Part throttle all the way to redline, but unhappy when goosing it (just like your video)

Yeah I doubt it's that, I know how to read instructions my man so it's where it's supposed to be for the car to operate. Solid red light when key is on the on position. Letting me know the car is ready.

Another thing to potentially check is the condition of the MAFS and the CAS itself.

The Mafs I just replaced, I kept the old broken mafs just in case, I got a video of my idle because when the car is in limp mode it runs rich and shoots out black smoke and backfires. This also will happen if I remove my knock sensor resistor and the car wont drive past 3000 rpms.

The cas on the other hand could be the culprit, my hot pipe literally touches it. And may have damaged it, visually it looks fine. But I know electronics normally aren't heated to 200 degree's either.

These is the same harness and same components you've always had/used?

The engine used to be in an s13, the harness was converted for an s14 that's the only difference. Once the harness was converted and I removed 5 feet of unnecessary wiring from the knock sensor, that whole deal stopped working.

One day we did turn the s13 on without a battery in it just to move it. Stuck a battery in, started the car removed battery and moved the car to pull the engine. It ran funny of course but I don't know what caused that.

[codyace]

Originally Posted by Om1kron

As you can see in the video water temp to the cluster itself doesn't work, but neither do the odometer and the other little 4 number indacator that I am putting mileage on it.

Sometimes people tap into the cas signal to get tach signal to make it all work. You see this on s13 harnesses especially. It could be a poor connection here being the lack of tach culprit, but this connection wouldn't be intermittant in regard to how it ran

Originally Posted by Om1kron

Yeah I doubt it's that, I know how to read instructions my man so it's where it's supposed to be for the car to operate. Solid red light when key is on the on position. Letting me know the car is ready.

I'm not doubting your ability to read, just doubting the crappy 20 year old ECU's we all like to tinker with. I've had ones where the tape is still OE, and you goto do a quick diag and it's like fubar from the get go.

If these jiggles into the slightest bit of diag mode, the car do EXACTLY what you are experiencing...when I first got my SR running ages ago, it did what your car is doing...this is why I always check that little POS screw out as some of the lamest electrical problems can result from that thing not being happy.

Again, food for thought. Maybe not your solution, but something to keep in mind.

Originally Posted by Om1kron

This also will happen if I remove my knock sensor resistor and the car wont drive past 3000 rpms.

The car throws a 34 anytime it drives with knock hooked up right? What about going to the junkyard and grabbing any ole knock sensor, and just attaching it to the frame/some other place just to make the circuit happy, but disregard knock? I know it sorta defeats the purpose of the KS, and that your resistor may work, but if removing it causes the car to run like crap as well...then I'd also be looking into whatever you did with the KS

Originally Posted by Om1kron

The cas on the other hand could be the culprit, my hot pipe literally touches it. And may have damaged it, visually it looks fine. But I know electronics normally aren't heated to 200 degree's either.

Hard to say. That big plastic covering is just that...just a big plastic covering. If you take yours apart you'll see most of the electronics and the ring are way down inside it. It's worth a shot though with these. They can go bad. Look at FWD Sentras and Honda guys...when dizzys go bad, it sound similar to your car as well. If the signal is messy messy, it could send improper signal to fire the c-packs, and well, that'll happen. Those stupid CAS's are really chinsey inside too... almost scarey to th ink that's how they all work ya know?


I'd start be re-introducing the KS that you removed, and look at whatever was done to convert it to the s14 harness. If it ran before, and the engine was all happy before, then you just gotta look at what was changed. It's an electrical issue for sure, so I'd spend less time looking at hardware (pipes leaks etc etc) at this point, as it's not going to fix the stumble.

[PoorMans180SX]

If you want to pay for sending me that valve cover back and forth, I'll give it a decent polish job for free. It won't be mirror finish, but it will look better than that! hahaaha.

[Spitfire8o5]

your car is attractive man, good work!! keep it up

[lflkajfj12123]

my knock sensor is fucked on my KA i have to run premium otherwise it starts running super rich and wastes my gas

[Xbroke_kidX]

Pictures really dont show how nice this car is. I wasnt to amazed from the pictures but I saw it in person at K1 and it looks really good. Good job man.

[Om1kron]

Thanks a lot, I appreciate it. I feel the same way about Forrest Wangs S14... looks like a boring black car on vskf's in pictures. then you see it in person and it's even quiet while drifting.

[Xbroke_kidX]

Plus Forrest's amazing driving makes it look even better.

[Om1kron]

I think Flybert had some similar problems with his car, turned out to be a bad maf... that fixed it for a bit. he got a power fc d-jethro and eliminated the maf and car runs great now.

I've pretty much narrowed it down to an engine management system to fine tune everything to the bone and just switch to map.

I hate dealing with maf, but the cost of converting doesn't even seem to be worth it. I just want to drive my car...

[importdude]

hook up consult and see whats happening with the sensors and what the ecu is doing

[Om1kron]

I don't have mine hooked up, but it looks like I'll have no choice but to get it wired up.

[codyace]

Originally Posted by s0apgun

my knock sensor is fucked on my KA i have to run premium otherwise it starts running super rich and wastes my gas

Does it go off if you just attack it to another spot(IE: Intake manifold, firewall, etc etc). I know that removes the point in even have it, but a stock KA shouldn't ping, so if you just attach it to 'nothing' it'll leave it in the non knock map and you should be set.

Again, it's a crude way to 'fix' an issue.

Originally Posted by Om1kron

I think Flybert had some similar problems with his car, turned out to be a bad maf... that fixed it for a bit. he got a power fc d-jethro and eliminated the maf and car runs great now.

That's why I suggested that from the get go. There is NO reason for it to sit there at that RPM like that this side of an electrical issue.

If you just want to drive your car, and aren't going for the biggest HP, just throw a rom ecu on the car and enjoy it. I'd hate to spend all that cash on a EMS with a map to fix such an easy issue ya know, as it's still not guaranteed to fix the issue.

Originally Posted by Om1kron

I don't have mine hooked up, but it looks like I'll have no choice but to get it wired up.

Super Easy. Just get a plug from any old Nissan and wire it direct. I like keeping the port on the passenger side as well, as it eliminates cables all across the steering wheel and my legs. It's a great tool.

[importdude]

Originally Posted by Om1kron

I don't have mine hooked up, but it looks like I'll have no choice but to get it wired up.

just grab a plug like posted above(g20s are right in front of dash very easy to remove

and or just directly wire it to the ecu harness
its 5 wires only

[Om1kron]

I have the plug. I just don't have the wires in place on my f3 plug for the consult. I know which pins it is, I just snipped the wires and tied them to the side. There is a post on here somewhere to show how to wire it back up.

But I eventually plan on getting a twin scroll setup for my engine hence why I would buy a standalone engine management system. I have a few knock sensors but even on my KA both still threw 34. It's normally some gay wiring issue.

My maf wiring is fine, because I can put a bad maf on their or keep it unplugged and it runs limp and makes my spark plugs black, backfires and all that madness.

this was with a boost leak before I changed the turbo housing, same wiring setup. before I did the knock sensor trick.

[Om1kron]

So I flipped the ECU today to do the proper code procedure. I believe I left the ecu in the position to read codes, 55 when I flipped it around automatically when I put it on the on position.

So I did the red bulb mode 1 engine off testing, bulb works. pass.

I did the mode 1 engine one test, engine warm 2000rpm, no light. pass
(if the light comes on it means bad ecu or cam angle sensor error.)

I did the mode 2 engine off test after running the engine, engine off key set to on, 5 slow blings, 5 fast blinks. pass

I did the mode 2 engine on test, 5 slow blinks at running temp solid 2000rpm rev. pass
(this is to make sure the 02 sensor is working.)

So I'll let you know if it runs any different now that it's back to it's proper position all the way counter clockwise.

[Om1kron]

My car officially hates me...

drove to LA today went to girlfriends moms, around the corner from the police academy... some cops roll by my car, check it out then do burn outs onto the on ramp lol.

I'm driving home in bumper to bumper traffic after stopping in old town pasadena to pick up new years tickets to menage.

I hear a pop and my battery and brake light come on, I immediately pull off of the freeway in front of someones house, pop my hood and somehow the alternator belt came off, and in the process grabbed my TPS sensor and snapped it off of the throttle body.

Wires are a little fucked, but both studs that hold it in place are now broken inside of the throttle body.

I am sitting here trying to figure out how in the fuck i'm going to get this belt back on the alternator, turns out the nut that holds the pulley in place came loose. So it's been vibrating back and forth and gave the belt enough slack to come loose.

So I took the nut off and the pully, wrapped the belt around it and pulled it back over it's stud, screwed on the nut and secured it temporarily with the gum I was chewing.

The throttle position sensor I grabbed two zip ties and tied it down in place for the time being.

It got me home, no problems.

FML.

[OBEEWON]

Originally Posted by Om1kron

So I took the nut off and the pully, wrapped the belt around it and pulled it back over it's stud, screwed on the nut and secured it temporarily with the gum I was chewing.

The throttle position sensor I grabbed two zip ties and tied it down in place for the time being.

LOL, thats some McGuyver ish. Are you sure you aren't Jamaican??


For real. The car is just working its problems out. Dont be too discouraged. You'll get everything worked out I'm sure. Wish I could give you the answer but looks like you've been over everything I can think of or someone has mentioned it.

But the fact that the ECU is giving you 55 makes me suspect a MAF. ECU won't see a bad MAF, and the idle test/limp mode test is not 100% fool proof. OR there is a leak that opens up at boost.

Can you drive smoothly past 4 grand without boosting or does it break up either way?

A) If it's under boost I had an issue with my spark blowing out due to gap (I was at 22 psi).

B) Or it could be a bad coil pack, they break up intermittently when going bad especially higher rpm under boost. Check them for cracks.

C) Also check your timing. Restab the CAS per FSM, even go as far as checking the dimples on the chain.

[s13pignose]

Originally Posted by OBEEWON

LOL, thats some McGuyver ish.

Beat me to it lol, sick work.

[codyace]

If you did the wiring, I'd just recheck what I've done at that point and go from there. I (myself) dont' trust myself with the wiring stuff...to me it's cheaper to just pay 100 bucks to get it done...man oh man I'd be wanting to shoot people over wire issues. As I tell my buddies...I'll stick with engine building

Originally Posted by OBEEWON

But the fact that the ECU is giving you 55 makes me suspect a MAF. ECU won't see a bad MAF, and the idle test/limp mode test is 100% fool proof. OR there is a leak that opens up at boost.

Most certainly. ECU's will not always show all fault codes. I never thought about suggesting that.

However the stumper, is that hte car will rev and pull to redline, so long as he doesn't go WOT immediatly...but can at redline...it's very odd.

Did you watch the video? It's not a hardware issue if you ask me...electronical for sure (including maf/sensors). I'm just confused as to why it's depending on part throttle...maybe it's reverting to some sort of wacky pull timing map, but it shouldn't restrict the RPM's from revving...which is why I initially thought it was failsafe mode of some sort, or the stupid ecu holding out...it's just odd odd odd.

[OBEEWON]

Originally Posted by codyace

However the stumper, is that hte car will rev and pull to redline, so long as he doesn't go WOT immediatly...but can at redline...it's very odd.

If this is the case then I would get on a dyno and look for a leak opening up at positive pressure.

I had a hairline crack on my hotpipe that opened up to about 1/8 inch under pressure. Couplers and aluminum charge pipes especially like to open up when boost is climbing. Usually found on the higher pressure side of the intercooler before the pressure drop.

[codyace]

Ah man that's a killer! Of all things to bust off too, the freakin TPS

Did the car run any better? Who did the harness for you, yourself?

[Om1kron]

I did the harness myself...

car didn't really run any differently under load.

I think what pisses me off the most is after I had to zip tie the tps back onto the throttle body for the time being low end response is like twice as good as it was before, but still breaks up past 4000 rpms lol.

[lflkajfj12123]

haha you could have just used your girlfriends pantyhose for a temp belt

[Om1kron]

the belt didn't snap or get damaged, the alternator just let it come loose. Luisgonz said that it felt loose and it has been squealing as of a few weeks ago. I should've tightened it.

[lflkajfj12123]

yeah squealing = loose on every one of my s chassis