angela_itr

What might cause sudden fuel/boost cut, on a partly tuned car that has otherwise been running ok for a couple of months? Problem is getting worse, ie it used to do it only occasionally when boosting, its now difficult to get it on boost at all cos it just keeps cutting out. I've changed the plugs but this made no difference. Afrs are generally good, tho at 5500rpm it reads VERY rich, ie <10. This is a problem with the map, but could it cause the fuel cut symptoms that I'm seeing?

Car is a B18C6 running 4.5psi with adj. fpr, 440cc injectors and Hondata.

By the way it feels exactly the same as when I used to hit the boost cut which was set on the Hondata, till I got a smaller w/g spring... ie one minute you're boosting, next minute you're heading for the windscreen

angela_itr

Anyone got any ideas on this one? I've read a few posts about fuel/boost cut so some people out there must know what I'm experiencing!!

angela_itr

Sure feels lonely around here...

Anyway I'll answer my own question... after doing a search for "boost cut" rather than "fuel cut" I found some interesting posts about problems with the Hondata blue box and ribbon, so perhaps that will be the cause of my problems.

Otherwise, please feel free to jump in with some helpful advice???

JonnyCoupe

u do realise the time in the US?

orangeturbogsr94

Well I think if your getting fuel cut then you are not getting enough gas into your motor and you might need to retune your car.

angela_itr

oops forgot about time difference Mind you I did post yesterday and no-one replied to that either

Anyways thanks for the reply!

Mase

hi angela,

I was talking to andrew about your situation over AIM just now.

do you have datalogging enabled on your hondata? if so, datalog what its doing and email it to MaseTuning@yahoo.com

chances are its something within the tune, I know you said the AFR's are ok, but if the car goes too rich or too lean it can cut hard sort of like the boost cut. same with ignition timing. i know you said its gotten worse over time, so if the weather has changed quite a bit, it very well could be just the tune, and nothing mechanical.

if the check engine light comes on, its for sure the boost cut.

be very careful however, my advice is to not boost until i make it to england in a couple weeks and will fix it for you

angela_itr

Hey Mase, thanks for the reply

Unfortunately didn't get datalogging with my Hondata, didn't think I'd need it... doh!

I was just saying to Andy that I sometimes get a flashing light on the Hondata box, so possibly faulty box or ribbon. I guess I'll wait till you come over though rather than go out doing my own iffy diagnostics... would hate to blow the engine up so close to getting it sorted!

Anyway will be good to meet you in a few weeks - hope the journey is a good one

Mase

yes, unfortuantely, these motors can blow rather quickly with a bad tune, we'll get it sorted out.

im gonna bring a spare p28 ecu and hopefully another hondata s200 box with me.


i know its hard not to boost on the car, but its much safer that way.

email me if you need anything else, as sometimes i dont see everyones posts here on honda-tech.

Turbo E

what are you plugs gapped at and how old is your O2 sensor? if you are using HOndata, make SURE you use a genuine HONDA O2.

all others make your car run like poo.

nfn15037

Probably the spark blowing out. Check the plug gap and take it from there