Help! B16 Miss fire @ VTEC!

[040501912]

Hi guys,

I have this weird problem with the car atm

On idle and before Vtec the car runs fine, no codes nothing.
very responsive as if nothing is wrong. i can drive it normal from a to b with out hitting vtec, partial throttle or just pushing it before vtec (not pedal to metal)

but then! once you cross over the to vtec
it switches ( which i could tell from the exhaust/intake tone) but its hesitate to rev up and missfires
as in the rpm is not going anywhere! (does but very slow!)

and then.. after the vtec is engaged and disengage
at cruising rpm under the Vtec rpm its misfires on partial throttle not until you put more into it the misfires is gone.. but it will back again once you partial throttle it.

the problem will go away Until you switch off the car and crank it up again.

All i've done prior to this problem is that i replaced some parts

Taken head off, acid batch, mild port polish
Cams
Valve springs retainer
Adjustable cam gears
New seals from head gasket up.
exhaust manifold

and thats it, we put it back together.

The ecu that im using at the moment Spoon PW0 obd0 which comes with vtec controller. i did not have any problem at all prior to the above upgrade.

When we put it all back together we marked the Dizzy and the cam gear adjustment is pretty much 0 0 on both side, and checked the timming.

Plugs and leads are not even 5000 km.
dizzy was working flawlessly prior to this.

No check light on the dash, and fault free on the ecu led.

i know the car has not been tune properly yet, but it should have able to go vtec with out any problems, even with out a tune.

i have no other clue :( please help me

If you have any info or know how to resolve the problem please let me know! :)

Thanks!

[tiksie]

Best thing to do before anything is to chuck in an OEM ECU in there unless the Spoon ECU is a piggyback off the normal one ?

I've had similar issues with VAFC-II installed (was tuned by TODA aswell) and car was running very rich and shit at top end and misfiring a lot. After I removed it from by B16, it got rid of 50% of the problem.. The next 50% of the problem was fixed by putting the timing to standard. But seeing as you've touched every base, might just be something wrong with the ECU ? Or must be tuned for a totally different setup ? This could very much be a culprit with aftermarket ECU's

While you're at it, you might aswell change your plugs as they're probably fouled if it was missing at top end. Just take them out and inspect just to be sure before going ahead with anything else.

[TODA AU]

Hi guys,

I have this weird problem with the car atm

The ecu that im using at the moment Spoon PW0 obd0 which comes with vtec controller. i did not have any problem at all prior to the above upgrade.

If you have any info or know how to resolve the problem please let me know! :)

Thanks!

What rpm is Vtec set too?
Have you checked the mixtures on the dyno?
Bridge connector & set timing correctly + set Vtec to 5700rpm.
As above check/change plugs/gaps & try again.
& as above also test against a std ECU.


I've had similar issues with VAFC-II installed (was tuned by TODA aswell) and car was running very rich and shit at top end and misfiring a lot.
Really? How come you didn’t bring it back to get it sorted out?
It’s also pretty strange that the ignition timing was out since we set it to std with the connector bridged for VAFC tunes?
PM me your rego so I can look it up, I’m pretty keen to see the graph.

[IV73CI]

sounds like your engine is knocking once VTEC is engaged.

Knocking or engine detonation is normally caused by incorrect air/fuel ratio, ignition timing, fuel delivery, incorrect ECU tune and or faulty sensors - basically if it detects any of these, your car will run in Limbo mode and or Safe mode.

its weird that your ECU is not throwing any CEL codes, but could also been disabled within the function of the Spoon program?

you should really get your car on the Dyno with a 02 wideband sensor to detect if your car now runs lean/rich which will cause your engine to detonate or knock. Especially with your new cams, valves springs etc ... incorrect valve clearance will cause your car to run crap too.

[040501912]

What rpm is Vtec set too?


we set the vtec at 5200 on the dyno on previous tune


What rpm is Vtec set too?
Have you checked the mixtures on the dyno?


Ran 13.5 - 13.7 on WOT accross rpm on previous dyno
Spoon ECU + AFC (apexi air fuel controller)



As above check/change plugs/gaps & try again.
& as above also test against a std ECU.


Will try this, and see how it goes. :thumbsup:

[tiksie]

What rpm is Vtec set too?
Have you checked the mixtures on the dyno?
Bridge connector & set timing correctly + set Vtec to 5700rpm.
As above check/change plugs/gaps & try again.
& as above also test against a std ECU.


Really? How come you didn’t bring it back to get it sorted out?
It’s also pretty strange that the ignition timing was out since we set it to std with the connector bridged for VAFC tunes?
PM me your rego so I can look it up, I’m pretty keen to see the graph.

It was on my old civic, I think the rego was XX-7888 (From memory) I got some photos of it somewhere which would have the rego on it as I bought the car like that. The thing is, I didn't know of the problems because when I test drove it, the car was cold and there was no problems when it was cold.. The issue always started when it warmed up.

[dougie_504]

Is the Spoon ECU tunable or pre-tuned? What cams are you using? Is the VTEC maybe engaging too early for the profile you're running?

[040501912]

Is the Spoon ECU tunable or pre-tuned? What cams are you using? Is the VTEC maybe engaging too early for the profile you're running?

Spoon ecu is Pre-Tune PW0
Skunk2 Stage 2 cams

[TODA AU]

Spoon ecu is Pre-Tune PW0
Skunk2 Stage 2 cams
LOL, I missed that in your 1st post... cams
Time to be the party pooper...
The so called "Spoon" ECU was never intended for anything other than standard camshafts.
Your issue is either the cams or the the ECU... Change 1 & you'll sort out the issue.
ECU to full programable & get it tuned or
Cams back to stock.

[dougie_504]

Yeah the ECU will probably engage VTEC too late for your liking (sluggish mid-range) and your cams are probably dumping in too much fuel for the ECU.

Go full tunable ECU and you'll see much better results/smoother run.

[VT3C]

Yeah the ECU will probably engage VTEC too late for your liking (sluggish mid-range) and your cams are probably dumping in too much fuel for the ECU.

Go full tunable ECU and you'll see much better results/smoother run.

Nah man its the opposite, vtec is too low with the obd0 spoon ecuwith those cams, needs to be about 5800-6200.

Adrian, interesting u say that about the ecu, mine is obd1 and who knows which version chip (one through six)but when I ran stock cams the spoon ecu ran super rich into the high 9:1's!! Then after fitting spoon cams she feels a lot leaner with hardly any pops n backfires than before with near-stock fuel consumption... maybe the ecu recognized the cams were his cousins ;)

But don't get me wrong, tunable ecu + good tuner > spoon ecu.

[dougie_504]

IMO there's little to no point in a non-tunable ECU. Sure it might let you rev to 9,000RPM or whatever but you'll never get it smooth I reckon...WOTAM.