S14 Sr20det Idle Problems/Jumping Idle. *VID*

[ZenkiSkidz]

Figured i'd start a new thread to deal with these issues. (one that actually has a correct title lol)

"Previous Thread With More Info"
http://zilvia.net/f/showthread.php?t=548227

Here are some updates and a little background info. s14 notchtop sr20det, apexi ax53b70 turbo kit, nismo 550's, tomei 256/11.5 cams, z32 maf, WS Upper and Lower harness, ISIS 255 pump, enthalpy tune.

1. Before i sent out the ecu for a tune, the car would idle high at around 2k and bounce between 1800-2500. While waiting for it to get back i took off the IACV and cleaned it thoroughly. I also relieved tension on the throttle cable that i believe was causing it to idle to high.

2. After the tune, and the ecu being "fixed" (had a broken connection somewhere on the old daughterboard) the car runs sooooo much smoother. and holds it's AFR alot more steadily now. But it's still around 9.8 average.

3.After adjusting the IACV and throttle cable, the car now idles at 1k perfectly, but still bounces up and down between 800-1100. I cant seem to figure out whats causing the bounce. When i first started the motor, it wouldnt bounce one bit. It ran really rough, and fouled out the plugs after 1 minute of running, but it DIDNT bounce.

4. Unplugging the MAF causes the car to die out, not idle better. And trying to start without it plugged in..doesnt happen. lol.

5. Unplugging each coilpack individually makes a difference on each cylinder. So im guessing they're all firing?? *******After unplugging the last coilpack (rear) the car started to sputter and bounce so i plugged it back in and shut the motor off (this is before i sent it out for a tune). Every start since then it has bounced and started "idle hunting" so maybe i fried an electrical connection somewhere?*********

6. On partial throttle it spits and sounds like its misfiring??

7. I read that a loose BOV could cause a funny idle, and mine just so happened to be pretty loose so I tightened that up (but couldnt start it again since its late).

8. I dont think its a vac leak since it's running RICH but i dont know???

9. It really kinda sounds like it's running on 3 cyl. Whats the best way to check for spark without taking the CAS out. Although i should probably just take it out and reset timing anyway...i just really dont feel like pulling the VC again.

10. Plugs were still fouled after the run you see below. which was around 2 minutes or so. But they DEF werent as bad as before, and the car wasnt blowing nearly as much crap out of the exhaust, just blackness...due to idling at 9.8 lol

11. I also noticed it doesnt seem to go through a warmup cycle?? it just starts right up (like a really healthy start imo) but jumps right to 1k and starts bouncing

Most of the rattles you hear in the vid below are from my IC rubbing on the hole i cut, so ignore that.

Need help and things to check/diagnose! ive literally looked all over the place before posting this so please dont tell me to search. :bigok:

Literally willing to paypal whomever helps me get a working solution. I just want to drive this damn car!!

Vid:

HtLkIuG9JJo

[cotbu]

9.i just really dont feel like pulling the VC again.

Take the valve cover off and look for a thrown rocker arm.
8. I dont think its a vac leak since it's running RICH but i dont know???

A vacuum leak after the mafs, will make you run rich.
Pull codes
Next time you feel like starting it, check timing, mechanical and ignition.
I assuming fuel pressure is correct, and enthalpy turned off the knock sensor for testing because you told him your engines runs like shit.
There's just a lot of noise and if it's not knocking then a bad mafs or vacuum leak could explain the 9.8afr. but... that up and down fluxing of boost gauge and rpm is indicative of a thrown rocker. most likely the exhaust side.

9. It really kinda sounds like it's running on 3 cyl. Whats the best way to check for spark without taking the CAS out. Although i should probably just take it out and reset timing anyway...i just really dont feel like pulling the VC again.

remove the fuel pump fuse crank the engine a few time then remove the a spark plug for testing, connect it to the coil pack and hold it next to an unpainted metal surface, have someone crank the engine. look for spark. use caution!

[ZenkiSkidz]

Take the valve cover off and look for a thrown rocker arm.


A vacuum leak after the mafs, will make you run rich.
Pull codes
Next time you feel like starting it, check timing, mechanical and ignition.
I assuming fuel pressure is correct, and enthalpy turned off the knock sensor for testing because you told him your engines runs like shit.
There's just a lot of noise and if it's not knocking then a bad mafs or vacuum leak could explain the 9.8afr. but... that up and down fluxing of boost gauge and rpm is indicative of a thrown rocker. most likely the exhaust side.


remove the fuel pump fuse crank the engine a few time then remove the a spark plug for testing, connect it to the coil pack and hold it next to an unpainted metal surface, have someone crank the engine. look for spark. use caution!

sigh....if im pulling the VC tonight ill reset the timing and pull out the CAS. Also i dont really know how to pull codes with this ECU?? It's a WC but doesn't have the flashing LED or knob.. (obd1 s14 zenki car)

thing is about the fluxuating idle.....is during the first and second start...it held idle. like....even though it was idling like shit...it wouldn't budge from where it was (give or take 100rpm)

The surging really started after I unplugged a coilpack with the motor running...started idle hunting...shut off motor...re plugged the coilpack harness back in..started motor again....idle hunt ever since..

what's your preffered method for checking vac leaks? carb cleaner?? (im new to sr20 and boosted applications).

oh and any rattling or knocking you hear is from the intercooler hitting the bay, and upper end noise. ive listened hard and none of it is coming from the bottom end. Ill check for the thrown rocker later and report back.

[OnTheChip]

Sounds like it's just running really rich. Since you don't have a tunable ECU, if you have an adjustable FPR, try lowering the fuel pressure as a test and see if it clears up.

[cotbu]

If you have the consult wires in the ecu harness wire them up to a consult port, you can get a consult port from WS IIRC. Then pulling codes gives you 2 options consult port and shorting consult pins. I think you can short those wires without the consult port but im not sure so i won't say which wires.

Assuming everything is working correctly and the 9.8afr is correct. There are only a few things that will make that happen. Knock map, big vac/boost leak, and leaking injector(s) are the one that come to mind.
Pull the fuel rail and prime the lines does fuel leak from the injectors

When pulling the valve cover, you don't have to keep pulling the cas, verify timing first and if its off, then make changes but once the cas is installed correctly leave it alone untill you can set base timing and idle rpm. with a light.

he surging really started after I unplugged a coilpack with the motor running...started idle hunting...shut off motor...re plugged the coilpack harness back in..started motor again....idle hunt ever since..
This does sound like a leaky injector that is killing spark, try pulling the injector plug instead.

that 9.8 isn't lambda right?xd
post results

verify these pins on your wc ecu wiring harness first, they should be the consult wires and check engine light
pin 21 RX
pin 22 TX
pin 31 Clk
pin 32 Check engine light
the ground and 12v ignition should be easy to find

[Kingtal0n]

sounds like a mess, your first mistake was sending out the computer before getting the vehicle to run properly. your second mistake was letting someone "tune" an ecu that was broken.

Sounds like back to basics. Put a different stock computer, stock injectors, stock maf, time the engine, check for boost leaks, verify that it runs like an OEM engine should.

THEN start changing over parts.

[ZenkiSkidz]

When pulling the valve cover, you don't have to keep pulling the cas, verify timing first and if its off, then make changes but once the cas is installed correctly leave it alone untill you can set base timing and idle rpm. with a light.


This does sound like a leaky injector that is killing spark, try pulling the injector plug instead.

that 9.8 isn't lambda right?xd
post results



Ordered a fuel pressure gauge so i can see what that's at, should be here monday. Didn't get a chance to go to the car tonight but ill definitely pull the VC today and check out the rockers.

Cotbu - i havent been pulling the CAS. i haven't touched it since getting the motor. sorry for any confusion. but once i get the VC off im going to pop it out and reset the timing.

Ill also pull the fuel rail and check to see if they're leaking. I really feel like that might be a root cause. Maybe one is sticking or clogged or something. regardless it would be a good idea to clean it/them out anyway so i might aswell.

"that 9.8 isn't lambda right?xd
post results"

honestly have no idea what you mean here man, lol.

and ill also check out the harness for those pins. Its a wiring specialties harness so i'd assume they're there.
sounds like a mess, your first mistake was sending out the computer before getting the vehicle to run properly. your second mistake was letting someone "tune" an ecu that was broken.

Sounds like back to basics. Put a different stock computer, stock injectors, stock maf, time the engine, check for boost leaks, verify that it runs like an OEM engine should.

THEN start changing over parts.

1. Every mod you see listed CAME with it already installed while in japan. I got this motorset from JEI in virginia (in the link to my first thread it had this info) and was told it was a good running motord. The cams are super clean and fresh, valvetrain looked great, and the turbo has zero shaft play. I dont HAVE the stock injectors, stock maf, or a different computer (especially when i know for a fact mine works great)

2. I had the ECU tuned by Enthalpy because this isnt a custom setup. It's been done many times, and i just needed something good enough to get me moving and to a real dyno/tuner. He sent me a video of my EXACT ecu hooked up to a car and it was running and idling properly. I had NO idea what tune was previously on this ecu while it was over there so i wanted to be safe. Also he was the one who found the broken connection on the old daughterboard, took it out, replaced it with a new DB.

3. I will check the lobes/chain links to make sure its set correctly, re stab the CAS, and will build a boost leak tester tonight/tomorrow so i can be 100% sure its leak free.

Thanks for the suggestions!

[Kingtal0n]

1. Every mod you see listed CAME with it already installed while in japan. I got this motorset from JEI in virginia (in the link to my first thread it had this info) and was told it was a good running motord. The cams are super clean and fresh, valvetrain looked great, and the turbo has zero shaft play. I dont HAVE the stock injectors, stock maf, or a different computer (especially when i know for a fact mine works great)



Well it sounds like the engine was well taken care of. That could mean you have a very simple problem related to the chassis or plumbing.

I would still start with the basics. You DID pressureize the plumbing for leaks, right? you DID verify the ignition timing, right?

A stock computer, injectors, maf, intake tube, plug, will run less than $200 and make diagnosis much smoother.

[codyace]

Do every single step PLMS describes:
plmsdevelopments.com/sr_setup_tips.shtml


And then we'll start troubleshooting.

Random shot in the dark: You do have the factory o2 hooked up right? Or at least have the wideband set to send a narrowband signal to the OEM wires/ecu...