S14 Sr20det woes

[DCmonkey]

hello Nico club.

not the way i saw myself coming to this forum but anyway here we go......

brief story

wanted a work truck but also something i could maybe hoon around with too sometime so project zombie truck came to life. few months later i purchased a 97 D21 4x4 that was previously SR swapped and the motor which i was told was still good...... see where this is going yet??? well i fell in love with how the truck looked since it reminded me of some fun times in Afghanistan so i took her home.

so you guessed it! motor was poo poo once i started seriously inspecting, no time for crying so i had a machine shop refresh and rebuild the head and i ordered a new short block from jdm of miami.

got it all together eventually ... yay everyone is happy.......wrong, wont start....

start playing the wiring rodeo with the harness that was probably put together by what looked like someones autistic cousin(no disrespect intended, just pissed off)

so off i went to wiring specialties for a new universal harness to eliminate the disgusting craftsmanship. got everything in..... no fire, ripped all the oem wiring in the engine bay out to let the engine operation be completely stand alone of the body harness(hardbodys have a one piece harness vs 240's) now interior does its own thing plus power the fuel pump until i can tap the fuel pump (+)pos to the specialties harness and specialties harness only worry's about the engine. sounds like a solution right??? wrong. fired up, but with vac leaks.... fixed leaks, triple check everything again.....


ANYWAY after checking the timing, replacing the CAS, CTS,MAF, plugs, i am 100% stumped.

she turns on, idles then warms up and starts to idle low and crappy and with an awesome fragrance of 93 octane
cold she pulls -18-19HG vac and then drops to a stumbly -10HG. when i try driving her she pulls OK at first then under load she has almost nothing. i hear the turbo spooling and everything , but i doubt shes even making it past 3k(again no gauges, kinda flying blind)

as it sits this is what she has so far
97 hardbody xe
s14 notchtop motor
WE ecu
oe inj,FPR,t25
-Wiring specialties pro-harness
-FMIC and piping
-looks like a turbo xs rfl or rfl style bov atmospheric
-ISIS turbo elbow

*FPR vac line T'd with gauge
*wastegate actuator vac line plumbed to nipple on cold pipe close to throttle because thats the only nipple the pipes have.
*bov has vac from TB
*everything else has been capped except for what i believe are the coolant lines on the side of the TB.
*big nipple on cold pipe plumbed to big gold pipe by TB(forgot what it is right now)

no exhaust because i live in a huge uphill and the muffler shop is in the bottom of the hill. in her current condition/power delivery she will NEVER make it up again.

things ive checked.

Vac- T'ed boost/vag gauge to frp line for readings
CAS- replaced it just to be sure(stabbed in per FSM with VC off)
VAC lines-replaced them all
CTS- harness requires new style round plug so i purchased one from advance auto.... had flooding issue, replaced again with autozone unit..... ran it,check plugs no signs of flooding.....?still strong smell of gass anytime ive ran it
MAF-one that came with the truck had a crack in the plastic body, so i replaced it with a known working one for safety.

things to mention
-o2 not hooked up because i have to hammer the firewall a bit to accommodate the fat type 02
-gauges havent been wired since ive been so stumped here.
-no downpipe
-no exhaust
-buddy thinks fuel preasure might be low based on eyeballing how the fuel spit out of the line(key word eyeballing......yes unreliable)
im not very nissan savy, have had a long history with hondas so im not mechanically dumb.

i know the SR only requires 4 things to run properly CAS,CTS, MAF,TPS....... what am i missing if i'm getting fuel and spark????????

Ive floated around online looking for similar or identical probs and honestly havent had much luck since ive noticed a lot of SR owners dont like to share their knowledge. called Wiringspecialties a few times, no solution, called CIP motorsports, told to check grounds, put boost/vac gauge, check cts, no solution.... been fighting to get her runing right since christmas :'(


I am pretty much feeling like this project might get cut off soon since the dream of romping around in a sleeper sr-truck is starting to seriously fade.If i don't solve this soon i will probably junk the truck and pull the motor to try to cut my losses



any help,tech advice, suggestions will be greatly appreciated!! I live in CT in case there are any locals who might be able to help.

Danny

[DCmonkey]

bump...... any help is apreciated

[DCmonkey]

bump again..... forgot to mention under throttle she sounds like she wants hit boost, sounds like shes boostin but shes not moving as fast as she sounds .....???????

[MeanGreenS13]

I am going to direct a friend of mine here to hopefully help you out... As far as I know with the SR, the O2 affects the engine at idle and part throttle. So I don't really think that's going to be an issue if you are having problems under load. I could be very long so don't quote me but I would still try hooking up the O2 to see what happens.

Also, have you tried another ECU? That could very well be your issue.

[DCmonkey]

Thanks brother, I really appreciate it. I have not tried another ECU yet. yuri from wiring specialties insists I rule out the ECU and harness........ The o2 from my understanding only come into play once the car goes into open loop so I doubt it could be affecting the idle like that, but this is my first Nissan so I could be wrong

[DCmonkey]

Bump. Forgot to mention I could not get to the knock sensor so I left the oem harness on it and plugged it into the wiring specialties harness, the only thing worth mentioning is that the prev owner cut one wire off. I was told the knock only needs one wire to run because he other just serves as a ground so I should be good...... Anyone care to confirm??

[DCmonkey]

spent some time working on the truck today and managed find and address a few things like the knock sensor only had one wire that was attached so i finally grew a pair and used the supplied sub harness from wire specialties, took the valve cover off to make sure timing was set and it was dead on, CAS was actually a bit off center so i centered it. started her up after everything and it ran great. -20HG dead on so i ran it till she would normally start bogging and stuttering and low and behold she did it again, but this time i had my brothers helping me do some wrenching and luckily my younger brother discovered a drip from the gas tank which turn out to be a pretty decent leak coming from the sending unit which explained why the engine was constantly trying to recover idle. so i pulled the plugs anyway to see if she was flooding and all 4 were nice and ashy for a change as opposed to all blacked out which is good news.

ordered a new fuel pump and sending unit all together and a new OEM O-ring for it.......i already have a fresh set of plugs and 300zx TT fuel filter, so when the new sending unit comes in ill throw it all in together and see what happens.

i think the culprit now is a shot fuel pump/sending unit because prior to what seems like the fuel system loosing pressure, it was running great.


one step closer i guess.

[MeanGreenS13]

If none of this fixes it, get an ECU.

[DCmonkey]

That was going to be my next consideration

[MeanGreenS13]

I honestly would have gone that route long ago. The worst thing that happens is you have a spare ECU, which with the age of these engines, is not a terrible thing to have just in case.

[DCmonkey]

Very true. When I built my integra I had about 5 different ECU's lol

[DCmonkey]

i know this might be a dumb question but, should i consider buy a red tag WC ECU or not even play around and get the matching ecu??? from what ive gathered in my internetz travels, the red and black WE/WC ecu's are interchangeable as long as you mind the type of MAF plug. Anyone care to confirm/advise me before i do something dumb.

[MeanGreenS13]

I have always matched ECU numbers. I never took a chance on playing with that. Not every ECU is pinned the same so if you overlook something accidentally it can get costly. I don't know much about the S14 SR's, only S13s really, but I just by simple rule of thumb always get exactly what was there.

[DCmonkey]

true. well i ghetto rigged the fuel pump leak with jb weld, fixed the coolant leak and ran it again and still having the idle issue. managed to take her down the street and it ran ok but felt sluggish. what are SR's known for doing after the tps is unplugged while its runnning?? i unplugged mine and it idled high as soon as i did it when it idled low n burbly.