Worst SR20 problem known to man. help?? LONG AND DEADLY $25 reward

[Chrischeezer]

hello, I'm currently running an redtop sr20 in my s13, But having major issues, and if u could give me some insight it would be greatly appreciated. hopefuly u can make some sense out of this. heres what im working with..

engine harness (new)
HKS hg
HKS cams 264 272
arp studs
greddy springs
greddy ras
port and mild polish
3 angle valve job
custom valves
nismo 555cc injectors, used
nismo fpr, used
warbro
z32 maf
gti-r turbo
new O2 sensor
new temp sensor

Bottom end:
BRAND NEW EVERYTHING (besides crank)
ALL OEM parts.


fresh ECU (off a swap) sent for a rom tune (twice!!)

nothing is half assed, i tryred to do everything PERFECTLY.
the car drove fine for the first 10-15 miles. with out problems

NOTE: remember, i drove the car for 2 days, and this happen out of nowhere...

heres my problem i hope someone can shed some light on the subject

-Key on ... fuel pump makes a small thud.. and i get 5-10psi
-start: car starts up right away, fuel pressure is holding 42psi, the motor just gets PIG rich, 10.0
car sounds like it has a misfire.. idle bouncing, FUEL dumping hardcore out the tailpipe. motor revs up fine, seems powerful and fast reving. REVS ALL THE WAY

-pulled plugs: every single one looks the same, DRY, but fouled out BAD.
-re did the CAS and put the motor in time. same.. problems.. only when i move the CAS down to the MAX does the pump turn on for a sec.
-motor compression is 150 ish across
-i have been through a million plugs, maf's, coilpacks, CAS, O2's...
-checked, checked and checked and checked MAF wires
-tryed 3 MAF's
-replaced all injector O rings
-then tryed another ECU and the fuel pump came on, when Key was ON.. BUT! the car didnt shut off.. i would pull the key out and power will still be on
-so i tryed another ECU and NOTHING.. no fuel pressure at all.. car would just crank and crank..


-so i still had i gut feeling it was the ECU, i get a known working ECU (stock) and a afc NEO (2in6out)
i tryed to start.. SAME EXACT PROBLEM..i noticed the motor doesnt respond if the MAF is plugged in or not, How is this possible, with the MAF unplugged i can rev the motor fully.. and same with it plugged in.. it just runs PIG RICH

also im new to the Neo and i cant seem to get air flow% on the screen.. anyone know how?.. it doesnt give me an option of what sensors to view.

have any thoughts?
please help me out, im loosing my mind, and i really dont know where to turn

thanx,
Chris

even if someone can call me and maybe guide me through a few things,
cell 9175764600

reward for fixing : 25 bucks via paypal!

[Healtoeae86]

Try gapping your plugs tighter , just do it to .020 to see if it helps any. Also if your dumping a lot of fuel double check the injector o-rings.

Even after i replaced mine, it did the same thing, it turned out that i accidentally pinched an o-ring causing a leak and the motor would literally dump fuel out the exhaust. Be sure to oil up the o-rings really good with motor oil prior to installing on the rail.

Good luck!

[Mikester]

Are the ECU's you're subbing in tuned for Z32 MAF, taller cams & 555's?

[Chrischeezer]

.. plug gap.. nahh doesnt make sense
replaced all O rings used vasoline.

mikester- did u read the post?

[teccabest]

where in NYC are you? i think you might possibly just need a 255walboro pump or something.

[xxxjovaxxx]

i agree with tecca, did u do the walbro 255lph fuel pump??

[s13rookie]

have you tried running it without the neo. if you have a tuned rom, the neo would not be needed for other than fine tuning.

also, i didnt see if you said you had a CEL or not

Did you check to make sure there wasnt a banana in the tailpipe?

[Chrischeezer]

no cel's

help MEEEEEEEEE

[s13rookie]

you have a used fpr right? do you know if its good?

i didnt think an fpr was required if you had a larger fp, injectors and a tune-but i could be wrong.


have you tried it without the neo?

[Chrischeezer]

you have a used fpr right? do you know if its good?

i didnt think an fpr was required if you had a larger fp, injectors and a tune-but i could be wrong.


have you tried it without the neo?

i have tryed many ECU's, two rom tuned, one stock anf only one with the Neo
the FPR works i know that.. i get 42 psi and its totaly adjustable when the car is running..

[rps13drift]

Your wiring harness sounds fucked up! but if your sure its ok then i would
Check for boost leaks/faulty couplings
check all your grounds especialy the one on your coil pack harness
check your coolant temp sensor

[spunkysandoval]

^Agreed. If your coolant temp sensor is out of wack than the car dumps copious amouts of fuel to try and warm up. It literally thinks it's freezing.

If you can monitor things on the NEO try and monitor the temp sensor. I'm not entierly sure, but I think it probably will have a 0-5 volt signal that decreases when the temp goes up.?? It's been a while, but I'm kinda sure this is correct.

Good luck. :thumbup:

[Nismochop95]

if you maf id disconnected and the car still runs then something is wrond with the ecu harness make sure the ecu you are using is for your model and all of the pins are correct especially the maf's

[bongnak]

cehck your ignitor chip

[slider2828]

I would suggest you get back to basics and rewire the mafs for an sr20 mafs and change the injector back to stock. THen just plug a stock ecu back in there. That is the only real way to make sure everything was installed right and all he wiring working. But it does sound like a mafs issue possibly or a timing issue. Is timing on the ball? Also check the CAS to see if that is working. But swapping everything over like that all at once is proven to give youa headache. Good Luck

[johngriff]

Nope.

If it pulls all the way through the rev range without missing, it isnt:

Plugs
Gap
AFM
Wiring.

Its just rich. Your Rom sucks. Buy a standalone. Tune it. Be done. Have fun.

You can send me the $25 now, plus 1475 for a haltech ;)

[Chrischeezer]

i know its long but, plz try to read the post before posting an answers that makes no sense at all.

-i replaced most parts you people are recommending, PLEASE READ MY POST, i dont wana come off as being an asshole, this car is killin me..sry

-The motor doesn't respond to the MAF, at all.. even if its unplugged, it still rev's up..
johngriff- there is no rom tune, i cant even lean it out with the afc... doesnt respond..my 2 first ECU, i tryed, were ROM tuned for myset-up, they are proven just as effective as a standalone... (maybe not as versatile)

its like making its own fuel curve... like limp mode, but what can do that besides
o2, temp, maf? What can make the ECU fall into limp mode and not read any MAF reading?

[Chrischeezer]

I would suggest you get back to basics and rewire the mafs for an sr20 mafs and change the injector back to stock. THen just plug a stock ecu back in there. That is the only real way to make sure everything was installed right and all he wiring working. But it does sound like a mafs issue possibly or a timing issue. Is timing on the ball? Also check the CAS to see if that is working. But swapping everything over like that all at once is proven to give youa headache. Good Luck

-1st off.. thanx for a sensable responce.
yeah the motor's timing has to be right.. i drove the car before it was good.

changing everything back to stock is a good idea.. but a PIA. since i dont have a stock MAF or stock injectors...

does anyone know the CAS works? how does it control fuel?, when i turn the sensor down to the MAXIMUM the pump kicks on for a split sec.

[johngriff]

-1st off.. thanx for a sensable responce.
yeah the motor's timing has to be right.. i drove the car before it was good.

changing everything back to stock is a good idea.. but a PIA. since i dont have a stock MAF or stock injectors...

does anyone know the CAS works? how does it control fuel?, when i turn the sensor down to the MAXIMUM the pump kicks on for a split sec.

You want to get into an argument with me over semantics? When your obviously bullshit opinion that your ROM tune is better than a standalone?

Is your rom tune telling you right now that the tps signal isnt reaching the ecu?

Anne get your gun(multimeter).

[Chrischeezer]

You want to get into an argument with me over semantics? When your obviously bullshit opinion that your ROM tune is better than a standalone?

Is your rom tune telling you right now that the tps signal isnt reaching the ecu?

Anne get your gun(multimeter).

WHHAAOO!!! reeelllaaaaxxx who said anything about a ROM tune being better (don't people read anymore) if anything i supported the fact that a standalone is better, but in this case a ROM tune would have an effective alteration to the cars air fuel curve at idle, just as a standalone would.
.. and Yes my afc will tell me voltage of my tps..anymore BRAIN BUSTERS!??!?

[johngriff]

It seems like the TPS signal is not reaching the ECU. When you unplug the TPS it goes into "timing setup mode". Sounds like its in Timing setup mode. This mode is usually ignored on ROM tunes for INJ corrections, will run dumb rich, and completely ignore the AFM input.


-so i still had i gut feeling it was the ECU, i get a known working ECU (stock) and a afc NEO (2in6out)
i tryed to start.. SAME EXACT PROBLEM..i noticed the motor doesnt respond if the MAF is plugged in or not, How is this possible, with the MAF unplugged i can rev the motor fully.. and same with it plugged in.. it just runs PIG RICH


This is symptomatic of the TPS signal NOT reaching the ECU. Sorry, I didnt see that you had a rom tune, and now you dont. Thats even better, stock ecu and an afc trying to control 550's.


nothing is half assed, i tryred to do everything PERFECTLY.
the car drove fine for the first 10-15 miles. with out problems
:rolleyes:

I cant relax, i have had two rockstars, a quad mocha, and had to beat a homeless man out of my shop today. :keke:

[drifxtfx1]

ok i had the same problem car was runnin extremely rich. it would not even crank with stock ecu. u need to go back to stock with everything of find a good tune for it. i had a rom tune in mine and i took the chip out an put it into another ecu and now runs fine. if that makes sense just get an ecu which is for it

[Chrischeezer]

It seems like the TPS signal is not reaching the ECU. When you unplug the TPS it goes into "timing setup mode". Sounds like its in Timing setup mode. This mode is usually ignored on ROM tunes for INJ corrections, will run dumb rich, and completely ignore the AFM input.



This is symptomatic of the TPS signal NOT reaching the ECU. Sorry, I didnt see that you had a rom tune, and now you dont. Thats even better, stock ecu and an afc trying to control 550's.


:rolleyes:

I cant relax, i have had two rockstars, a quad mocha, and had to beat a homeless man out of my shop today. :keke:

never herd of this "Timing setup mode" before, interesting... anymore info on this? think its possible the afc would still read it (show voltage), and the ECU woudn't?
- i know, using a AFC is so limited, but i had to try it on a STOCK ecu, ur right i def. need a stand alone in the future, but i just wana get a few miles on this motor first.

keep the ideas commin ppl

[email protected][email protected]$!%[email protected]^$#$&$%#@!#%$!#@$%#$



I cant relax, i have had two rockstars, a quad mocha, and had to beat a homeless man out of my shop today. :keke:

LOL omfg....

ok i had the same problem car was runnin extremely rich. it would not even crank with stock ecu. u need to go back to stock with everything of find a good tune for it. i had a rom tune in mine and i took the chip out an put it into another ecu and now runs fine. if that makes sense just get an ecu which is for it
yeah that makes no sense to me at all... im just guessing u didnt read i think i wrote, i tryed 4 ECU's.. 2 with rom tunes for my set-up one with an AFC neo

[johngriff]

The sensor will output voltage, and it might be getting to where you tapped the AFC, but if the pin in the ecu has too much resistance, it could just be not getting to the board. Test the continuity between the ecu connector pin for TPS signal, and the signal output wire.

When you setup the base timing, you disconect the TPS, and the ecu references a different map to control the idle and accurately set the base timing. This ignores the AFM input and just does its own thing. If you are DUMB rich, and AFM manipulation is making no change, and the tuned ecu's are making no change, you very well could be in this map.

[drift into a curb]

Try new injectors (not just o-rings). Sounds like it's the injectors dumping too much fuel to get 10 AFRs. This was doing something similar to mine as I stuck my injectors in and the rings pinched like heeltoe's but I got new injectors and it solved the pig rich problem.

[Chrischeezer]

Try new injectors (not just o-rings). Sounds like it's the injectors dumping too much fuel to get 10 AFRs. This was doing something similar to mine as I stuck my injectors in and the rings pinched like heeltoe's but I got new injectors and it solved the pig rich problem.

ok will do.. ill try to get my hands on some 555

The sensor will output voltage, and it might be getting to where you tapped the AFC, but if the pin in the ecu has too much resistance, it could just be not getting to the board. Test the continuity between the ecu connector pin for TPS signal, and the signal output wire.

When you setup the base timing, you disconect the TPS, and the ecu references a different map to control the idle and accurately set the base timing. This ignores the AFM input and just does its own thing. If you are DUMB rich, and AFM manipulation is making no change, and the tuned ecu's are making no change, you very well could be in this map.

ok.. so say its in that map.. how would i get it out?

[johngriff]

fix the obstruction of the signal to the ecu. I have seen a couple ecu pin failures where the connection is intermittent or completely terminated.

[Chrischeezer]

gotcha.. ok, ill check it out after i get some sleep
thanx

[SRfairladyZ]

All fingers are pointing to TPS. I Think I have an S13 one laying around, But check your wiring first.

[Slidin240Wayz]

you shouldn't adjust your CAS to the "MAXIMUM"...set it up correctly to 17 degrees.

[slider2828]

I think its an SR so that is 15 BTDC is correct timing. Really timing mode? I time with the TPS connected and don't have a problem. Oh wellz....

[johngriff]

I think its an SR so that is 15 BTDC is correct timing. Really timing mode? I time with the TPS connected and don't have a problem. Oh wellz....

If you set up base timing like this, the car will seem super aggresive, and fast, but will be detonating balls on cali 91. The correct way is to set the timing with the TPS disconected, this lets the ecu know that you are setting base timing, and will retard the timing to a "no advance" map.

I have seen cars like this, where after you disconect the TPS and get a read on the timing, its like 28deg. The ECU makes corrections, but there is only so much, and I have seen lost motors, blowby, headgasket all because of incorect timing setup.

By other shops.

[TUnity2]

sounds like wiring issues, possibly with the chassis. was it once an auto chassis? and if not, the running rich problem may be a coolant temp sensor.

[johngriff]

Coolant temp isnt going to make the ECM bypass the AFM. Chassis, no, all the chassis harness does is provide switched power like it would to a head unit. 12 v on, 12 v off, and grounds.

[Chrischeezer]

-i set the timing with the TPS unplugged, the motor ran even worse. once i plugged it back in, it returned to normal fucking up mode. i check TPS pins in the ECU.. everything seemed perfect.

still stuck in this limp mode or failsafe mode.. cant get out..

[TUnity2]

Coolant temp isnt going to make the ECM bypass the AFM. Chassis, no, all the chassis harness does is provide switched power like it would to a head unit. 12 v on, 12 v off, and grounds.

maybe something important isnt getting 12v. like, air idle.

[johngriff]

Do the basic spark on all 4 and inj pulse on all 4. Test the injectors by grounding them out and do a compression test, i guess just the basics first would be cool.

[The Riot Hero]

check your NEO wiring, sounds like it isnt controlling the MAF input. and i cant believe no one has told this kid to check for vac leaks.

[steve shadows]

I cant relax, i have had two rockstars, a quad mocha, and had to beat a homeless man out of my shop today. :keke:


man i love newport beach haha

what john said you fail

[johngriff]

No fucking seriously.

This cat.

Straight out of the burbs.

Looked like the man had just lost everything (including his marbles) last week.

Had a manicure. But rode up on a bike, wanting his gran national rebuilt.

He had pictures on his blackberry.

But he was INSANE.

That is the homeless down here... lol

[johngriff]

check your NEO wiring, sounds like it isnt controlling the MAF input. and i cant believe no one has told this kid to check for vac leaks.

There is obviously some kind of evil input issue, since he can disconect the maf and it still rev's.


OH SNAP.

Answered my own goddamn question.

What is the Voltage @ idle on the input for the NEO for the maf.

Bad wiring = voltage bleedthrough pos to signal.

[steve shadows]

anything named neo and i cringe


i guess except the oil

[Chrischeezer]

check your NEO wiring, sounds like it isnt controlling the MAF input. and i cant believe no one has told this kid to check for vac leaks.
the stupid neo has nothing to do with it...
if their was a vacume leak that wouldnt put my car in limp mode, it wouldnt effect the fuel pump and the MAF the way it is.

even if the injectors werent firing at all and the coilpacks were on fire.. that wouldnt put the car into Limp Mode like it is.

PLZZZZZZZZZZZZZZZZZZZZ im dyin... i need help, no one has an answer for me. what causes this Limp Mode?.. fuel pump only primes for a split sec. the ECU isnt using the MAF

what about knock sensor.. does anyone know anything about that?
how does it work? can it put the sr20det code 62 ECU into limp mode?

[Nismochop95]

so i read this thread and you guys arent seeing the fact that if he disconnects his maf the car is still running.. i did a z32 maf in my car and if its not connected the car doent start.. but if the wire that sends signal into the ecu for the maf has any voltage then the motor will run.. and lets say it might be connected to i 12 volt source. if the ecu is readinf that source it thinks that a lot of air is going in and the ecu will compensate with fuel. thats why its pig rich.. he's messed with the harness and its real easy to get wires crossed..

here's a test..
get a multimeter. start at the maf with the car on check the voltage at the maf signal wire it should be something normal like something under 5 volts.. then go to the ecu harness and get a map of all the pins on the ecu and then check the voltage on the pin of the maf signal if it is different than what you saw at the maf then you got another test.. then with the ohm tester check to see if the wire on the maf is the same wire on the ecu.. if the meter goes to zero then it is and i have no more answers for you.. if it is staying at 1 then it isnt the same wire..and you have to rewire it...
oh if the voltages are different then that is a problem too.. remember the maf maxes out at 5v and at idle should be lower than 5v..

there's no need to swap parts.. if you need help pm me and i'll give you my # and i'll walk you through the test

[s13rookie]

so i read this thread and you guys arent seeing the fact that if he disconnects his maf the car is still running..

my car will start and run with the maf not plugged in. Most nissans have a default fuel map in the ecu that the car would revert back to if something goes wrong with the maf- but im talking about my maxima, so i dont know....


edit: if your car was running on the stock fuel map, that would explain why it is so rich. the ecu doesnt know about the larger injectors and pump. Have you tried resetting the ecu? you can have problems without throwing a CEL

[johngriff]

Nismochop95 just repeated what I typed in detail. I keep forgetting i have to explain everything in exact detail of "how to", i cant just put forward a theory.

Easy test. Disconect AFM. Key on, check input voltage on AFC.

The car will fire up w/o the MAF and rev to 2500. But he can wind it all the way out to 5k+ with the maf disconected.

[Chrischeezer]

.1 volts im reading off the MAF sensor, never changes..

the ECU is stuck in limp mode,
-where it uses a base fuel map and the pump doesnt prime itself,
only reason its running stupid stupid PIG rich is because i have 555cc...

sounds good?
.... i even E-mailed top secret, they never even herd of a problem like this...

PLEASE SOME ONE HELP MEEEEEEEEE..

[johngriff]

I think I am spent. It is really one of those things you have to be infront of to diagnose. Take it to a shop.

[The Riot Hero]

wiring wiring wiring wiring

[Chrischeezer]

how is it the wiring i drove the car the way its set-up right now..

[s13rookie]

how is it the wiring i drove the car the way its set-up right now..



Wires fray, unplug, melt, short. etc. It seems like everyone that has offered you any options is quickly shot down. You are making it pretty hard for people to want to help you.

[Chrischeezer]

- i know... im getting so frustrated, i need to clear my head a bit

thanx for not giving up on me just yet

i think im pull the entire harness off and connect my friends harness, yes wires could be broken someplace... currently trying to get a stock fuel set-up, MAF, and try to get the consult port working. but my nissan dealer doesnt have the consult I comptuer. i guess i need to get a laptop and software and an addapter

[foursidenine]

stuck injector?

[hayaimoto]

Might sound dumb but did you make sure you wired the neo right? If so when you lean out the narrow band under -17 does the car shut off or stall? Good luck on your prob. It seems like those "easy-but head ache" problems.

[neo_rambo]

^Agreed. If your coolant temp sensor is out of wack than the car dumps copious amouts of fuel to try and warm up. It literally thinks it's freezing.

If you can monitor things on the NEO try and monitor the temp sensor. I'm not entierly sure, but I think it probably will have a 0-5 volt signal that decreases when the temp goes up.?? It's been a while, but I'm kinda sure this is correct.

Good luck. :thumbup:

it would dump fuel to cool off not warm up.

[johngriff]

You would think, but it sends less fuel, as the reading gets hotter.

[SRfairladyZ]

Yea, I know bad knock sensors do crazy things with Toyota's (like limp mode and pressurize your wastegate actuator) , I don't know about on nissan's though. You can check your knock reading with the Neo i believe, I can with my SAFC2. Its a pretty useless function but, you can get some numbers on the screen and see if you have a signal. And do you really need 555's with only a GTiR turbo? Why not get a set of S15 injectors? Have you tried testing your computer on another Sr20? I know you have went through 3 computers or whatever but, I went through 3 MAF's before i eliminated my fuel cut issue.

[fro20]

wiring wiring wiring wiring

+1

I recently had the same issue, but with a dif setup. I run standalone and a MAP instead of MAF. Had the motor out for ~2months for rebuild and car clean up. All we did to may harness was clean up wires I no longer use etc.

So we knew we didn't touch certain things, but when we exhausted all other options we had to go to wiring. Check continuity and all seemed good, until we ttok harness out. TPS seemed to not be connected on the ground, MAP signal and 5v got crossed. Fixed the wiring and ran great.

So when we knew,"thought", we didn't touch anything, we actually needed to re-pin the tps at the EMS and the uncross the 2 of the 3 MAP wires.

Just check the wiring, u say no thats not it, but did u troubleshoot the whole harness yet for the sensors that could cause this issue?

I know its a PITA

[fro20]

how is it the wiring i drove the car the way its set-up right now..


Yep me too, but it was my wiring. That is where my money is.

Wiring or sensors. What have you changed since the car drove correctly?

I read the whole post like 20 min ago but dont remember everything.

[SRfairladyZ]

I read the whole post like 20 min ago but dont remember everything.

Hahah, so then read it AGAIN. :bash:

[opponheimer]

lol @ your thread title.

Sounds like a real shitty rom tune. Or your injectors are higher flow rate than you think.

[SRfairladyZ]

lol @ your thread title.

Sounds like a real shitty rom tune. Or your injectors are higher flow rate than you think.

READ the post, Stock computer, Car runs with MAF unplugged. Cant escape limp mode.

[Bad40r7]

Sounds like a stuck open injector to me

[Chrischeezer]

READ the post, Stock computer, Car runs with MAF unplugged. Cant escape limp mode.

thank you....

[mizono]

I think it might be your wiring harness. The voltage for the MAF at idle should be 1.7-1.8 volts and 0 with the motor off, not 1 volt like you said. Either redo your wiring/try friends harness or try another MAF.

[powersteeringless180sx]

did you ever figure out what the problem was?

[Chrischeezer]

yeah 5 computers later, turns out, the Stock ECU's i was getting werent stock at all.. they were ROM tuned ECU's.! but with out the tune in them.. just jumped and docked waitting a tune.

whats the chance i get thoes last 2 ECU's in a row that are both rom tuned with no chip.. one in a million.

i put about 1000 miles on the motor since then.. and the head lifted a little and coolant was coming out the back. so i ripped the head apart and re tightened the arp's and (sneaked the timing chain) then broke a cam bearing bolt in the head... spent 3 hours fishing that out.. now i need another one.

never ends, but for that 3 weeks i drove it around.. it was great.. felt so good. worth every problem.

[Jbma327]

check you timing at the CAS. maybe way off

[daryl337]

lol. I think he just stated he fixed the problem. :)

[mrs.drift33]

nvm ghdfggfdg