S15 SR20DET problems!!! please help!!!

[eyedefineJDM]

alright guys so heres my setup

93 S13 coupe
S15 SR20DET
Apexi head gasket
greddy oil pan
HKS SSQV
CX racing front mount
Greddy Z32 intake kit
Z32 MAF
Apexi AFC neo
HKS 3 in exhaust
Megan racing DP
Greddy turbo timer
Pro sport boost gauge
Walbro 255
Z32 fuel filter

so here's whats going on.... when the car is cold (not fully warmed up) it runs decent... only decent. in low rpm, no boost, it runs as it should. however, once i get into boost, all kinds of popping coming from the exhaust, really bad hesitation, feels like the turbo wont spool up any more. its only boosting to 5 pounds. once i get up to 5 pounds, it doesnt matter if i go WOT or not it just doesnt wanna move. prior to these symptoms, i was running a s13 sr MAF and the car would pretty much do the smae shit but it would hesitate at around like 4k rpm and then seem to get over a flat spot and pull hard as fuck! ive checked for boost leaks, ive changed my coolant temp sensor, checked my tps.... ive done fucking everything and this shit is driving me insane!!!!! im so tired of not being able to slide.... its killing me and i dont know what else to do......

[om3ga]

what changed when this started?

[StReeTz]

Have you gone through a tank of gas? Have you checked your MAF? What are your AFR's during this rough patch?

[krookedstyle]

Ccheck the maf or maybe the ecu if u know someone with an ecu to use to check if that's the problem and rule it out.

[japslapsilvia]

is your "in/out" setting correct on the AFC neo?

[eyedefineJDM]

Alright so I have a brand new z32 maf, rule that out, my hot wire in is 5 my hot wire out is 6, haven't touched anything else on the neo, rule that out, tps voltage is good, cam angle sensor is lined up, timing is stock, don't have a wideband yet but will be getting one soon, did a pressure check today and all my piping checks out, my plugs are gaped at .035 and are bkr7's, replaced coolant temp sensor, wastegate and bov hooked directly under the throttle body, I've checked all grounds, checked maf wiring....

I can't really get my hands on another s15 Sr ecu...
While I was running the s13 maf w/o neo, it would pass that hump of hesitation, since I've changed to the z32 maf and wired up the neo, once you give it gas and start to build any kind of boost, it is almost like it hits a barrier, like its rev limiting or something. The exhaust pops, and the car doesnt pick up any more speed. Fuel pump primes when I turn key to acc. Completely stock fuel system other thaN walbro 255 and z32 fuel filter. When I put it in nuetral as to come to a stop light, car wants to die, battery voltage drops down to under 10 volts, and sometimes does die. Runs f

[eyedefineJDM]

Bump... please guys any input is more than welcomed

[bkuhl]

try hw 2/5 or 1/5

[Sileighty_85]

Close your plug gap to a .28 or .30. .35 is a little big your probably blowing out your spark

[ayororo]

Goodluck wit ur sr man in havin troubles myself with mine

[slider2828]

Agreed with Sileighty, also check your fuel pressure? Change out the FPR maybe?

Also unless you are boosting remove the SAFC and try it again? Does it run normal?

[bkuhl]

Alright so I have a brand new z32 maf, rule that out, my hot wire in is 5 my hot wire out is 6, haven't touched anything else on the neo

your HotWire IN should be "2" with a N62 MAFS...and depending on what ECU you are running with your SR20, your OUT should be "6" for S13 or "5" for S14/S15...also remember to set your throttle voltage *AND* cylinders in the AFC Neo........

Close your plug gap to a .28 or .30. .35 is a little big your probably blowing out your spark

^^ this too.

Agreed with Sileighty, also check your fuel pressure? Change out the FPR maybe?

Also unless you are boosting remove the SAFC and try it again? Does it run normal?

Doesn't matter if he's boosting or not. He needs to make sure that the basic initialization/configuration of the AFC is done. He can turn off correction and let the ECU do everything else for troubleshooting.

[eyedefineJDM]

Alright guys so here's my nightly update...

I took the top half of my intake manifold off to check to see if my gasket was any good. Turns out on intake runner number four, there was a little puddle of gas just chillin in the bottom half... what the fuck? How the help does that shit happen.... anyways, I cleaned both halves of the manifold and bolted it down until the middle bolt stripped out...... shit! So Its pretty much just finger tight now... so I put everything back together, so I thought, and cranked it up, took it out for a drive and still the same problem... until a couple miles down the road I realized I forgot to put the fpr vacuum hose back on! Holy shit! How did I forget that? Thing is is that the car ran the exact same with the fpr vacuum hose hooked up?

Tomorrow morning ill change the hotwire settings on my neo and see how it runs.... I've got a brand new set of bkr6e's that I bought a while back that I already have gaped down to .025 so ill throw those in tomorrow also.

Just wanna say thanks to all you guys for helping me out. I really do appreciate all your help. Us Nissan guys gotta stick together! I'll let you all know what happens tomorrow night! Wish me luck!

[96Turbo]

puddle of gas in the intake runner suggests leaky ass injector

definitely try closing the plug gap a little, and whatever the AFC guys said

[eyedefineJDM]

Afternoon bump

[eyedefineJDM]

Well here's the update.

I changed my hw in and out to hw in 2 hw out 5. The car is more responsive but still won't let me boost more than 5 pounds and won't rev past 4000 rpm. When I drive around for about forty five min it gets worse to where it rev limits at about 3500 rpm.

Prior to installing the afc, just running the n62 maf, Tue car ran pretty good. Still had the rough patch but got over it allowing me to boost 14 pounds... I thought an sr wasn't even supposed to run with a z32 maf?

Still wondering why my car ran the same with the fpr vacuum hose off? I'm thinkin I need to start chasing a fuel problem.... I just don't know what else to do?

[Sileighty_85]

puddle of gas in the intake runner suggests leaky ass injector


Check this^^



.25 might be too small open them to .28 or .30

Your ECU might have been tuned for a Z32 MAFS, Never know

[eyedefineJDM]

how exactly do i check for a leaky injector??? and could that possibly be my problem with the whole 4000 rpm rev limiter?

[Sileighty_85]

I wrote the steps in here, Its really easy
http://zilvia.net/f/engine-tech/357510-engine-flooding-after-replacing-bad-injector-help.html

[96Turbo]

Have you pulled the codes? MAF wiring causes a rev limiter type of thing

To check the injectors, unbolt the fuel rail from the manifold (leaving all lines & stuff on). Then turn the key on so the fuel pump pressurizes the rail, and look for any fuel leaking out around the tip of the injector (none should come out). If it leaks, get new o-rings. There could also be a vacuum leak between the fuel rail & manifold, but it's not that common unless ur rubber insulators are fucked.

You can still drive without the FPR hooked up, but it's not good for a boosted engine. You set the base pressure (no vacuum hooked up), and then the FPR compensates +- from the base setting according to manifold pressure. So at idle (vacuum), it delivers less fuel, when you hit 0 it's at base pressure, and if ur boosting 15psi, then it delivers more fuel cuz the rail is at +15psi from base.

[eyedefineJDM]

sadly for some kind of reason my car wont show a check engine light unless something is like unplugged or some shit....

[96Turbo]

codes can exist without the CEL being on. check them out. that's ALWAYS the first step to diagnosing engine stuff

dunno how it's done on an S15, but with my S13 SR you just turn a screw on the ECU. on my RB you jump two wires together. read up on it

[eyedefineJDM]

damn i didnt know about that but check this out... my ecu doesnt have the light on it... ill check that out more though

[96Turbo]

Neither does my RB. So you gotta make sure the CEL is hooked up or it won't work. Or you could just rig up a bulb...

Is there a screw on it? Otherwise it's probably like mine and you gotta jump the CHK wire to a +12V source, and then the CEL flashes the code

[eyedefineJDM]

alright.... so check this shit out....

last night, i went to a buddy of mines place to have him help diagnose my problem. his house is about thirty minutes away so on my way, my car starts to fuck up real hard at 0 vacuum and 1 psi of boost. the whole way there, the car would not boost AT ALL! as soon as i got to 0 vacuum, the car would not pick up at all. it would bog horribly and it acted like complete ass while trying to boost. it did it all night, and most of today until!!!! until he decided to pop the hood and jiggled my power wires.... low and behold, the car wouldnt boost past 5 psi again, but it acted better??? dont know what the hell this is about.... however shortly after leaving his place and being on my way back home today, it started doing this bull shit again....

another problem has arisen.... now my car sometimes doesnt want to start.... fuel pump primes, but as soon as i try to crank it up, it wont turn over.... needless to say alot of push starts have been required to get the car to crank up. but its only sometimes. weird as fuck.....

anywyas ive been thinking hard all day, and i have somewhat came up with a theory of what my boost problem might be..... as you all can remember me posting, i have a puddle of gas in intake runner number four. keep in mind that this is only my theory.... maybe the rubber gromet that is used to hold the injector in the fuel rail is bad and is causing a possible boost leak and therefore leaving that puddle of gas in that runner???? i dont know.... the more and more i think about it the more it makes sense, but then again thats how people end up with a whole brand new motor when the culprit they're trying to replace is something dumb as fuck. which in all honesty is whats going to happen to me at the rate im going.... anyways, give me your input on all of this information.... thanks again everyone

[eyedefineJDM]

Bump come on guys

[nieko]

boost leak?

timing?

leaky injector?

all combined to give you a rad cluster fuck of problems?

[rb25_s13*CHUKI]

Check all Intercooler piping!

Check the rubber rings for the Injectors!

"I've got a brand new set of bkr6e's that I bought a while back that I already have gaped down to .025 so ill throw those in tomorrow also. "

^^ Get rid of those ASAP and get some bkr7e. bkr6 will melt piston rings with too much boost. Its too hot of a plug for turbo

Check your cam timing and Cas timing

Check ur turbo maybe Its fucked.


maybe need new injectors (I have set of top feed 690cc holla!)

maybe your blow off valve Isnt holding pressure.

Get new battery terminals

Get a new battery

Chec your idle air control valve.

Make sure all of your grounds are present.

Make some new grounds/

Take off safc and see how it runs then

Check alternator make sure It has the proper grounds.

Make a relay on ur fuel pump so It gets more power and doesn't fade out like most do.

When ur car Is on take off the negative terminal and If the car dies ur alternator Is bad.

[bkuhl]

Who did your install? Sounds like your electrical/wiring job IS horrible.


Depending how the SAFC was wired, he may not be able to just remove it. Might have to strip out the wiring harness and reattach the wiring back to stock; hopefully whomever did the wiring left enough slack or put some kind of disconnects on the wires (temporarily, of course.)

[Michael Nolan]

ECU problems?

[eyedefineJDM]

Will update as soon as I wake up.... just got done rewiring lower harness.... tired as all fuck

[eyedefineJDM]

Check all Intercooler piping!

already done pressure test on intercooler piping. all is good under 20 psi.

Check the rubber rings for the Injectors!

just ordered new injector o rings and cushions

"I've got a brand new set of bkr6e's that I bought a while back that I already have gaped down to .025 so ill throw those in tomorrow also. "

just bought another set of bkr7e's

^^ Get rid of those ASAP and get some bkr7e. bkr6 will melt piston rings with too much boost. Its too hot of a plug for turbo

Check your cam timing and Cas timing

timing is spot on... 15*

Check ur turbo maybe Its fucked.

has a little bit of play but the turbo still spools up properly.


maybe need new injectors (I have set of top feed 690cc holla!)

will check this out very soon....

maybe your blow off valve Isnt holding pressure.

blow off valve is holding 20psi....

Get new battery terminals

all sensors are getting the correct power...

Get a new battery

dont need one....

Chec your idle air control valve.

no leaks, and it is also getting correct power

Make sure all of your grounds are present.

good to go...

Make some new grounds/

made 2 new grounds that go from the chassis to the motor...

Take off safc and see how it runs then

since im running z32 maf, it goes into fail safe mode...

Check alternator make sure It has the proper grounds.

check!!!

Make a relay on ur fuel pump so It gets more power and doesn't fade out like most do.

dont know how to do this....

When ur car Is on take off the negative terminal and If the car dies ur alternator Is bad.

alternator is good...


so the only things on this list that need attention are my injector o rings, need to make a relay for my fuel pump (will search this), and injectors might possibly be bad.... almost positive they arent... i think i just have a leaky injector....

[bkuhl]

how'd it turn out bro?

[s15specR]

Get some copper NGK's gapped to .27 and try it again, I had the same problem and it turned out to be the plugs.

[eyedefineJDM]

so after doing an entire rebuild on my motor due to main bearing number three getting ate up, i have found the problem... plugs... wow. my frikkin spark plugs were the culprit.. i took some NGK iridium IX's right out of the box and boom, they did the trick. thanks for everyones help even though just about everyone overlooked one of the most simple things. just thought i would put out my last post on my old thread so that if anyone else has these symptoms, they will know to look at their plugs... the smaller the gap, the more likely youll get cut out, the larger the gap the better gas mileage you get and the better its going to run however you will also risk blowing out the spark... so gap as wide as you can without blowing out your spark. or just buy Iridium IX's from NGK and call it a day!!! again thanks for all the input and help.