Hey, I am from CSUS Sacramento and we are using a CBR600 motor with a Performance Electronics ECU. Same setup as the other cars that use it, 20mm restrictor, no forced induction...

So the car starts just fine, but it idles rather erratically for about 5 seconds and then the revs just shoot up like someone floored it. I can't tell you how high it can get with the lack of air flow (throttle is completely closed here, any air getting in would be through the idle hole in the volkswagen TB we are using) because we always mash the kill switch as soon as it happens.

Do you have any idea what could be going on here? Has anyone seen anything like this before?

We haven't really messed around with it because we don't want to break anything. We're using a map that someone has made for this same engine/injectors/restrictor that is available on the P-E website.

Competition is in a week and we are WAY WAY behind schedule so any help at all would be appreciated...

 

Is that VAG TB by wire to mechanical?

 

have you checked for vacuum leaks?

 

Good thing you've been shutting it off as soon as that happens. I know under lean conditions, idling motors that shoot up can possibly be dieseling...detonating a bunch. I know it's always easiest to throw a map in there that someone said is good, but you should check your A/F ratios to see what's coming out of the motor.

 

yeah, the only thing i can think of is it's a runaway idle caused by a severely lean condition.

 

Thanks for the replies, I'll be heading there after work today to get our wideband setup and I'll make sure to check again for exhaust leaks... The TB is a cable type not electronic and it is using a MAP if that helps.

 

no leaks on the intake side? this generally happens in my old bikes if a carb boot is torn or air is short circuiting on the intake side.

 

The performance electronics ECU sucks, I know cause I tune the F-Sae car @ my school, I've hade some of those things go crazy with injectors, take a look at the tune, and if everything seems to be okay and you still are suffering from lean condition I would for sure try hooking up another ECU.

But before anything, look for leaks, intake mani is a common one, and TB to the mani is another common point. Make sure that the TB you are using has no form of electronic control, although I would belive you checked that before selecting it.

 

This is where we're at:

All sensors check out ok. Checked resistances on coils, voltage output of the crank sensor, etc... ECU says everything is ok as well. The only thing I haven't done as far as checking sensors and other electronic components is hitting them with an o-scope.

We tried messing with the lean condition. Put in 3 times as much fuel as the base map (that is made for a FSAE restricted CBR600F4i) just to see if it would start and not run away. Still took off. Triple checked for vacuum leaks. Can't find anything. Could the ECU itself be bad? We'll keep looking for stuff.

I do have an LC-1 wideband, but I don't have an available gauge and the Performance Electronics ECU doesn't have any way of easily viewing sensor voltage on one of their user inputs.

 

Thats exactly what I told you in the last post, if your tune looks fine and everything is still f*cked up, hook up a new ECU. The PE ECU is a piece of crap.

 

have you asked your questions on the fsae forums? you'd probably get more help there... although i agree with blindstuff. if you can find nothing wrong with the engine and ancillaries, the ecu is probably bad.