$amGD3

This is an issue I've been having for at least the last 8+ months

Car: 2000 Civic Si B16a2, boosted, 5 year old dyno-tune setup by John Vega (phearable.net) *nothing changed in setup*

Issue: Vehicle will cut off either on idle or decel/coasting to a stop (spark cut). Will NOT immediately start again, sometimes it takes 3 cranks to start again...other times it would take 30 times (Video below showing what it does when I try to start it after it dies and I tried to start it again)

As I said, it will either die when I'm driving and I'm in neutral coasting to a stop or in idle. I've had instances where I literally let the car sit and idle and sometimes it will take 30 minutes to die, sometimes 3 minutes. But it will ALWAYS die, without warning.




What I've tried:

2 ECU's
New coil, icm,wires, plugs
A whole different distributor entirely
New engine wiring harness (issue is/was present even with old harness)
Several main relays

Known facts:

It will die ONLY on decel or idle,it has NEVER died on accel
It does NOT blow any fuses
Fuel pump ALWAYS primes when attempting to start again
AFR's does NOT change when it dies
Black/yellow wire on dizzy IS getting 12v
There is spark on ALL 4 cylinders
CANNOT be replicated manually

What I haven't tried:

I took apart and jiggle the **** out of the ignition switch, cant replicate it, I'm getting another switch from the junkyard this weekend


I'm trying to think simple mechanics as to what make a car die on idle/decel and it wont start again...i'm stumped

I'm at the point that if I cant solve this, I'm going to sell this car, it has been a nightmare. I've spent close to $1000+ the last 3 months on parts/labor/diagnostic with nothing to show

thought?

SpeedRacerEX-R

IACV

antrmo

wow thats tough luck,possible the coil/wire grounding out somewhere?

$amGD3

can you elaborate?

I dont have any idle problems btw that's usually present like the surging and such

I may get a spare iacv from the junkyard this weekend, i presume a single cam EK iacv will work on my EM1?

$amGD3

Traced all of the wiring as I possibly can, cant find anything of the sort

also,

a bad ground would probably blow a fuse or only die when there's movement,vibrations,etc

veks

Any check engine light on? Fuel system was the first thing that came to mind.

$amGD3

no check engine light as seen by the video

I'm not sure if this happens all the time but I BELIEVE, when i crank the car, the cel remains on but ONLY when it's cranking....i THINK...not sure, will have to double check on this

fuel prime and main relay click can also be heard everytime

antrmo

i agree about the movement part, and that y i thought when you were on decel there maybe a bit of movement depending on rpm i guess,I dont know the shape of your mounts, and I dont think you would necessarily pop a fuse but just my 2 cents.

SpeedRacerEX-R

Hmmmm, when's the last time you changed the fuel filter?
Also, I think you would need an IACV off a b16, but I'm not certain on that. I know when mine was bad, it would die whenever the rpms would get under 1000.

B18c-R_ej6

I had the same issue on my B18c-r. Got a IACV off a D series at the junk yard, fit just fine but same issue. Cleaned out my denso IACV and the D series IACV with throttle body cleaner, tried both again and still nothing. What I ended up doing was just turning the idle up on the throttle body about 400rpm and it stopped.

$amGD3

Oem fuel filter is less than 1000 miles old

I cross referenced the part no, seems like a single cam vtec has same iacv

$amGD3

Turn the idle up? Details?

B18c-R_ej6

the screw just left of the top center.

$amGD3

Gotcha ,im guessing counterclockwise is higher


Also, so you had the same exat issue? Like it literally dies on idle/decal randomly and turning the idle up fixed it?

Did u have the same restart issue like the video?

B18c-R_ej6

Mine wasn't as bad at restarting but yeah, after cruising on the freeway it'd almost always die while coasting on an off ramp, and city streets it'd die rolling up to stop lights in nuetral. It progressively got worse and worse till I finally raised the idle. It used to idle at 900rpm but it'd randomly die while sitting or coasting in nuetral and I'd have to rev it to get it started again. After rasing the idle to 1300 it doesn't die anymore. And I dont remember which way to turn it to raise or lower idle. I just let it sit and idle while I tinkered with the screw, drove it, tinkered with it, drove it, just going back and forth with that till I found the lowest rpm it wouldn't die at.

SpeedRacerEX-R

What about cleaning the throttle body? Shouldn't we focus on fixing the underlying issue?

antrmo

2 wire iacv? it is standard right?

TheShodan

iTrader: (14)

Sounds like fuel pump.. just because it primes, doesn't mean it's stable. IACV on even 2000 si don't really for like that even if OEM.

Sounds all like they pump to me.

F1_Racer

Check your spark plugs to see if you're running too lean or too rich.

Have you tried putting in new spark plugs?

$amGD3

I understood everything but this Shodan lol

$amGD3

plugs are definitely on the rich side

Yes, there's a new set in there now...still cant get it to start again


Hoping to get it towed to my tuner tonight...we'll see what he finds

aznxboixx

Subscribed to learn the fix

TheShodan

iTrader: (14)

Sorry. looks like someone hit me with a tazer when typed that. Meaning to say IACVs don't really die on these 2000 Civic Si. Not to say that it won't happen, just that its unlikely. I'm the original owner of mine, and still have yet to experience any issue from that device.

Your symptoms seem more indicative of a failing / malfunctioning fuel pump.

$amGD3

Dropped the car off at my tuner last night, hopefully he can pinpoint the issue

DCFIVER

My vote is for IACV or related circuits....



If it was the fuel pump the issue would most likely occur under a load (accel)