original thread: https://honda-tech.com/forums/forced-induction-16/breaking-up-boost-2613385/

Any of you all have any ideas of what to try? I don't know much else to try besides a different hondata ecu. I have the hondata s300 program if anyone wants to take a look.

 

My guess is the issue is ignition system related still.

Who originally tuned the car ?
Why don't you take it back to them to have them troubleshoot it ?

 

Just a thought, I actually had someones map sensor vacuum become disconected and cause a similar problem. I didnt read the previous thread to see if what you had a stock type map sensor or a motec/gm 3 bar.

 

Generally when that occurs, the air fuel ratios will be completely thrown off in boost.

 

The MAP is fine. We thought about it and decided to go back to the OEM one just to see. The tuner adjusted for the stock MAP and the car still breaks up at 2.x# of boost. We pulled a coupler off the charge pipes and the motor would run fine to 7k rpm. The problem only under a load where boost is created. We tried a brand new dist. and new wires. Same problem. We tried new plugs, resistor plugs and non resistor plugs, and adjusted the plug gap. No difference. I am starting to think it is something in the S300 box that is wrong unless you all have other suggestions of what to check.

AFR looks good.

 

Now after all ur troubleshooting of the ignition, plugs, etc. You said the a/f is ok, the other thing you could check is resrictive air flow either to the turbo(i.e. too small of filter) or some kind of blockage within the intercooler and piping.. Just something to look at. I had a customer put a filter on his turbo after tuning and made it break up underload, took it off and car ran fine..

 

I pulled the filter off it when this was happening and it made no difference. I'll have to check the intercooler and see if anything happened to it to create a blockage but I am doubful. Thanks for the ideas though.

 

are you using the boost by gear option? if so what solenoid?

 

no, just a manual boost controller.

 

Try another wideband to make sure your wideband is accurate.
Try another complete distributor assembly from another vehicle which you know works perfect, none of the discount auto parts crap...

 

OEM HONDA ONLY!

Ive learned my lesson.

 

its your ecu..jsut took mine to get tuned and my ecu was bad!! check that

 

Pretty sure that's what it is. Still have not figured out anything and have tried about every part I know it could be but the ecu. I wonder if hondata will do anything about it if it is the ecu.

 

DATALOG TO SEE IF ANYTHING IS WIERD IF OK CHANGE DIST.

 

Already done that. Nothing looks off and we have tried numerous distributors, ignitors, coils.