Powelly

So after standing for nearly 12 months i've decided to take my Civic out for a blast...

It's misfiring banging etc at around 6-7k rpm sounding like not enough fuel is getting through maybe?

Since it's been standing i've replaced the manifold & downpipe and needed to extend the O2 wiring to reach the new O2 sensor position on the downpipe, could this cause it? I removed the tank to re-paint and underseal but made sure i reconnected everything the same replacing the breather unit on the side of the tank too.

It's basically a B16 that was tuned last year by a repetable tuner over here in the UK using Hondata S300, running 13psi it made 275whp (low i know) and was running fine right until i decided to take it off the road. I wasn't sure if the ECU even used the O2 sensor after it had been mapped?

I had this similar sound after the last manual boost controller broke and it boosted to 20psi, that's what makes me think it's fuel related.

I've just ordered a new fuel filter incase maybe it's a bit of stale fuel? Long shot i know.

So that's my problem, sorry for the long post but wanted to give a picture of what i have replaced incase they are the cause.

I could do some datalogging with the S300 if that would help? I have an underbonnet fuel pressure guage but cannot extend it to view when i'm driving

Also i did notice a green plug disconnected from the back of the block? If i remember rightly i was told this was the knock sensor? Think it connects to a pin type plug that screws into the block. It's not throwing any codes though.

Thanks again

1greatEG

I am having the same issues. Is yours only at wot.

joe111599

Could be ignition related. What did you gap your plugs at? Could be blowing spark out.

Powelly

Yep at WOT. I think you might be on to something joe111599, i did change the plugs and never gapped them at all! The previous ones were gapped 0.28 and the new ones looked a similar gap. I'm using NGK plugs think they were the BKR7E-11 type.

joe111599

Gap them and take it down the road...then let us know if that fixed it!!!!

Ammadien

^that was my guess too, not tight enough gap or not enough fuel(knocking).

Nate

TheShodan

iTrader: (14)

ICM might be going out, may be time for a replacement as well as a plug gap. you can either replace the internal coil, or go to external like a Mallory digital, MSD, or M&W.

Otherwise, if the spark keeps going out despite the gap, you'll be breaking up a lot to where you're replacing plugs all the time.

Powelly

Thanks for the replies, I gapped the plugs to 0.28 and it's running worse

Seems to struggle at idle now after gapping them, i did notice that another green plug this time underneath the vtec solonoid has broke so thought that could be it. Went and reconnected the plug but still no change in idle.

Wonder if i gapped the plugs too much this time? i used a feeler guage and now the gap is just below 0.30.

It is still running the standard coil pack so maybe time for a change...the plug leads all look fine to me.

Am beginning to hate this car now!

joe111599

Damn man...I thought for sure since it was running like **** at higher rpms that it was the gap because that is what my problem was a couple months ago. Well, keep troubleshooting and you will figure it out. Its probably something simple...hopefully! Keep us posted on whats up bro and good luck finding the culprit.

rs250nut

**** in the fuel, coil breaking down, faulty leads, change the plugs? Fuel pressure?

crucian

Do some datalogs and send them to me along with your calibration file to cruzancoconut2@yahoo.com Also in the mean time check everything that has to do with your ignition. Wires, coil, sparkplugs, rotor and cap. What kind of ignition setup do you have?

sleepencivic

you mentioned you changed the manifold? that would mess you tune up!!!

if Im understanding wrong and the car is as it was when you got it tuned try to gap the plugs down more...i had to gap mine down to .18 when i turned the power up..i tried a new oem coil,has ngk wires,ngk plugs, ran all the test on the distributor came back fine....some distributors are just weaker than others...if you dont want to try the plugs tighter test anouther distributor.....

Powelly

Yes i've basically changed the intercooler piping, bov, manifold & downpipe. I needed to extend the 02 wiring for the downpipe thats about it. It's running a cast manifold now and smaller 2 1/2 inch ic piping and a hks bov.

Today i opened the gap on the plugs to 0.30 from 0.28 and checked all the leads and inside the distributor, all looks fine. I decided as the only other time i have heard this dentination kinda sound was when the boost creeped to 20psi so i turned the boost down to 10psi from 13.

Overall since re-gapping the plugs and turning the boost down it hasn't really made any difference apart from it's idling better. It's breaking up still from around 5-6k rpm but up to there it pulls like a champ.

I'm gonna try and do some datalogging with the S300 (never done it before) and see if that sheds any light on the situation. I'm almost sure it's fuel related so maybe it does just need a re-tune.

Wonder if i turn the boost right down to say 5psi then check it wether that will confirm it needs a retune?

As daft as it sounds would the s300 still retain its tuning settings from my last tune even if the car has had a flat battery for nearly a year?

gringotegra

Try gapping the plugs down to 0.20... yes .20

Check the Cap and Rotor.. if they look sketch, change them with OEM parts..

94GSRMR

same issue here at wot.. may need a re tune

Garage 808 Hatch

Is it still the same gas from a year ago?

joe111599

.28 is a little on the high side...I have mine at .22. Dont know if you have tried that yet? And I dont understand how it could run worse at idle from closing the gap...that just doesn't make any sense at all.

How old is the fuel...like dude asked above?

sanman000719

.23 here

TheShodan

iTrader: (14)

Again, I don't think it is his plug gap at this point. Instead of just switch entire distributors, its time to focus on the internals of the distributor you have, such as an ignition system that is setup externally. Big power requires big spark.

Powelly

Thanks again for the replies, no it's using fresh fuel as i drained the tank when i removed it.

I've regapped the plugs to 0.20 and re-checked inside the distributor, the caps points do have some carbon deposits on them and so does the rotor arm. I gave them a quick clean and took the car out for some datalogging (not that i know what i'm looking at lol)

Car again idled rubbish, struggling to maintain a steady idle but out on the road it pulled alot better, near perfect infact. It ran well for a few pulls then started to break down again.

I've saved the datalog file and the movie of the runs, it's around 10mins long but photobucket won't support the file?

From what i can tell the ignition is all over the place, which i supppose is to be expected but seems to dip around 5-8k rpms around when the car is struggling.

I'm thinking it's more than likely the cap & rotor giving me these troubles as the fuel pressure is good.

I'll keep trying to upload these files and give you guys an update after i've fitted the new parts...i've ordered some new leads too.

Thanks so much you guys for the help and suggestions, rep to you

joe111599

I know you know your stuff man but what do you mean exactly by "big power"? lol. There are plenty of people running stock ignition pushing 400-500whp. Right??? Well I have personally ran 400whp with stock ignition with NO problems what so ever. I would say "big power" would be 650+ right???

joe111599

Man I sure hope you get this figured out soon! I will tell you this...always start with the least expensive thing to swap out. Don't always go straight for the big money thinking that will fix the problems. I mean...go ahead and change the cap and rotor and if it doesnt work then youre only out a few bucks. Not a few hundred. Know what I mean?

Good luck with everything...keep us posted bro.

gringotegra

Ive personally seen 786 on stock ignition...

jspeedy

just my 2 cents. When I first boosted my prelude I had hella brake up above 5k wot. Turned out my msd 8.5 wires were bad. I only found that out because there happend to be another build at the shop with new wires on it. Try that if you can borrow some from a buddy.

Psychoteen101

This leads me to believe your coil or ignition module is causing you problems. Honda ignitions are known to crap out and it usually causes the car to run fine then get worse as it warms up. Just visually inspecting these parts wont determine if they are bad, you have to actually test there output electrically.