jbballa9876

Hello zilvians, would greatly appreciate any advise or suggestions.

I have a rb25 swapped s13, mainly stock- stock turbo, fmic, greddy intake manifold. Did swap myself, set timing etc.

Ive been driving the car for almost 8 months now without a single problem, idles great at about 600 rpm, pulls strong etc.

Driving down the highway the other day and started to lose power so i pulled over, and couldnt get it to run smooth so got it towed home.

Now after doing a few checks: alternator checked out good, checked for spark on all six coilpacks/spark plugs. Checked vacuum leaks, nothing. I thought it was a bad maf so i replaced that and no change.

It runs like the timing is bad, no power stalls out idling after let off the gas. Also when i start the car the starter will only crank for a second before stopping, and then i have to try to crank again.

Could a failing CAS cause this?

I tried to be as clear as possible explaining my situation, I would greatly appreciate any input. Thanks, Jeff.

jbballa9876

gonna get battery tested, battery drains over night regularly. But when i jump start the car the battery still puts out 14.5 volts so confused. I will update soon
'

sexcii-zenki

check timing, check plugs, and do a comp test...see if that helps

jbballa9876

battery was good. plugs dont look too good but i dont know how the car could have gone from running great to running so bad

greenwood

just because the coils are getting spark doesn't mean that they are giving good spark at all rpms. I personally have spare coils that I know are good. when I encounter an issue, i swap coil by coil.

How is your ignitor?

where did it not run smooth? How is your fuel pressure?

Easier said than done, check out your wiring, look for bad grounds. My starter wasnt grounding right and that was causing my battery to drain overnight too. Have you always had the problem of your battery draining overnight?

jbballa9876

No im trying to remember what happened but the battery started draining like 3 months ago, and ive been unhooking it everynight. Fuel pressure is about 38 psi at idle with vacuum attached at 1000 rpms.

I have series 2 with built in igniters in the coilpacks. It runs like the timing is really off, im about to get a timing light and have a check, and maybe unhook the fuel rail to check the injecters.

Ill probobly end up going through the wiring this weekend to check for shorts or bad grounds too

greenwood

does it run like shit at all rpm?

jbballa9876

Yea its pretty rough altogether, I didnt want to rev it past 3 to cause any more damage. It will try to go back to idle at around 500, then almost stall then jump to 1000 and keep doing that. Thanks for everyones input so far.

chris300zr

Check each of your injectors- with the car running pull each connector one at a time and see if your idle changes. If you pull a connector, and the idle doesn't change you have a bad injector. Good rule of thumb on coilpacks, is you have sporadic misfiring around 3000-5500rpm you may have a cracked coilpack(I had this issue, bought some fresh ones from a friend and wrapped them in high-temp electricians tape to be safe). As far as the starter, sounds like a charging issue. Double check to make sure all your grounds are tight and you don't have any loose wires (Battery, fusebox, etc.)

GL man.

N3cronomicon

how is your afr's?

jbballa9876

i tried unplugging the injectors one by one with the car on and seems like they were all working. Ill try replacing the spark plugs, but it seems like a lot of power is gone for just spark plugs to be the culprit? but need to do this anyway while resetting the timing

oh and i dont currently i have an afr gauge, just running the stock ecu (series 2)

couldnt see any vacuum leaks anywhere, unless intercooler is damaged

Is there a cheap way to check the ecu for codes?

sexcii-zenki

im not sure on that jdm engine too much but most older nissans have a self diag on the ecu there should b a knob with 2led lights nex 2it...turn the knob to the 1 side and perform selfdiagnostic counting the flashing leds red and green or the check eng light should flash indicating a code...if i remeber right the red will b the 1st digit and the green is the 2nd...example red flash once and green flash twice meaning code 12...or the oposite...if it wasnt ripped off a sticker on the ecu will tell u how 2do it

by like i said im not sure if the rb ecu has that... gl

jbballa9876

unfortunately the rb uses a cable of some kind, not the blinking light. Gotta see about gettin the cable, just dont know if i want to continue investing in this motor cause its not the most streetable power combared to say a v8, but still makes you feel good nonetheless.

tomorrow i will be getting spark plugs and update some more, and try to narrow down possible problems.

i saw this about checking the codes but doubting it will work on s13? :

http://www.skylinesaustralia.com/for...how-read-them/

Fredward

did you check the timing yet? If it feels like the timing is off then that would be the first thing id check

jbballa9876

So i just did a few further tests and i will do a recap of my problem.

Car is running really rough and acts like it doesnt have any power. I took off the fuel rail to see if the injectors were working and all of them were good.

I also took out each spark plug with their coilpacks and each of them fired, and i just got new spark plugs to rule out bad spark plugs.

Fuel pressure is good, a little under 40 at around 1000 rpms.

I also got another MAF to see if that could be the problem, but still acts the same.

Could a bad coolant temp sensor, CAS or TPS cause the car to runs so bad, or partially working coilpacks??

No boost leaks either. Im running out of ideas now, when the car started running like this it didnt gradually happen, it happened all of a sudden, the first time I broke down. And also there is a bad parasitic drain somewhere, the alternator and battery both test good. I plan on taking the wire harness out to make sure theres nothing wrong.

Before this happened the car had been running smoothly, and when i broke down i wasnt doing anything crazy, just cruising down the highway.

fliprayzin240sx

Just to make sure, you had the battery tested to make sure its good right? You didnt just hooked a multimeter to it to check the voltage?

Google search on how to check for parasitic power drain...basically you'd have to get a test light, spool of wire to get from your battery down towards your fuse panel to troubleshoot which circuit is staying on when the power is turned off.

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jbballa9876

Yea i had the battery tested at autozone, im pretty sure it would only read volts. But yea i unhook the battery and it wont die

jbballa9876

It would really be great if someone knows how to check codes for rb25 in s13. I had a ka24e originally. The ecu doesnt have the leds, and I cant find out how its done

jbballa9876

it looks like im going to end up trying to hook up a consult plug, and buy the cable and software...

greenwood

Sorry if this was posted already. Have you done a compression check and made sure that you are running good vacuum etc. I would t buy that just yet. I bet it's expensive.

jbballa9876

I have a boost gauge so i could check my vacuum when i start it again. i havent checked compression, I rebuilt the motor recently and when it broke down i was only cruising, so not thinking its compression and i dont have the tester.

I know i should check timing also, but i set it a few months ago and it shouldnt have changed at all.

greenwood

I hear you. Compression check is cheaper than software. Can u post a vid and more specific details of its running shittiness? My friends RB was running garbage status, turned out to be Nast vacuum leaks and a bad TPS sensor along with a dirty maf. Cleaned all that up and she began puttering smooth again

jbballa9876

yea def thanks for the input, i will give the compression test a shot. Made great progress in finding the parastic drain, which turned out to be one of the fuel pump wires closest to the pump. I recharged the battery earlier, around 2 or 3 and is still at 12.3 volts.

So now just gotta find out why shes running crappy. Something broke all of a sudden for this to happen.

Also the consult wire isnt too expensive, found it for less than 40 on ebay, but i dont know which one is the right one for rb25 series 2. This is my only car, which is my "daily", but i always have the option of taking the train to class and walking to work.

^^ I will take a video tomorrow if i get a chance. It seems like its running rich though and not smooth, when i drove it around the block had all its power sapped...

ch1873857

you said you cant rev past 3k?

sounds like safe most

try unplugging maf . wont rev past 2 but may clear up your idle.

jbballa9876

no it will rev all the way up just rough the whole time. i thought it was a bad maf, tried replacing that but no change

Croustibat

How old is your fuel pump ?

jbballa9876

fuel pump is less than a year old, its a walbro. I seem to be getting pretty steady fuel pressure

monstersisson4466

Fuel PRESSURE doesnt actually rule out the pump, it just shows that the pump can flow enough fuel to get to the restriction in the fuel system... being the regulator. If the pump doesnt have enough FLOW then it would actually run extremely lean. We use a COTA. It tests fuel presure and the ENTIRE systems flow rate. On the vaccum at idle, does it stay at a steady hg? (EX. contant 14in Hg) or does it fludder around? fluddering around would indicate that it did indead jump timing or something like that..... Im rather new to RB's but its pretty generic engine performance diagnostics

chris300zr

FYI: static/base fuel pressure on an RB should be 43 PSI/3 Bar. If you DO have an adjustable FPR, try and set it to 43 PSI to see if anything changes....

monstersisson4466

sweet man ill keep that in mind for my RB. Much appreciation