Lude Generation

Guys,

I need a little help getting to the bottom of a problem of a weird flat spot...

This fault might not be related to the EGR but I'm just ticking off a possible.

Basically, on my h22-swapped EJ civic I've always ran an EGR delete (did it before installing the engine) & P13 JDM ECU.

The engine ran generally well but I noticed that if you tickle the throttle ever-so-slightly (tiny bit of gas then straight off the pedal) the engine revs would drop more than normal and return quickly.

Once I fitted my AEM wideband gauge I was able to see what was actually happening to the mixture, I was able to see that every time this "situation" happened the revs would drop and the mixture would richen from 14.x to 11.x and then return to it's normal 13-15 readings momentarily.

I was hoping this situation would be remedied with the install of my Apexi Power FC and full tune but it's still there

I spoke to a marine engine technician at work and explained the problem...before I even finished the questioning his answer was "have you removed the EGR?", heance why I'm now looking into that area and trying to at least tick it off from possible faults.

I've checked with the Apexi deocumentation and I can't enable the EGR even if I want to as it is one of the only things it has no control over due to there not being EGR emission laws in Japan.

Do other people have similar experiences? I'd like to nail this problem down as it's bugging me somewhat :-/

i think ratty is pretty close to this now

oh really?

ratty getting the same issue??

No not me. Still have egr.

Anyone else have a similar issue?

I don't have an EGR but I don't have a wideband either. Could it be TPS related? As soon at the throttle plate closes the TPS isn't allowing enough air to get it so revs drop and in goes rich due to the lack of air? I had to recalibrate my Hondata S300 TPS values.

Edit - Just reread your first post, you are using the OEM P13 ECU.

I've set all the tps thresholds manually so their spot on...along with replacing the throttle body as it did have a sticky throttle plate.

Its been tuned very well by some pros at Silverstone so I highly doubt its the map; add to the fact this issue occurred before it was tuned.

Just can't get my head round why it would happen

Sounds to me like your problem lies with the Tip-In or Fuel cut settings of your tune. Let me know if you need more info.

Is your TB bigger? I had to do a LOT of tuning around, below and just a above idle after fitting a larger TB to make the car behave like or better than stock.

I noticed the same dip when I removed my EGR a while ago now and had the S300 installed with EGR disabled - so very weird!?!?!

Very weird. I'm pretty sure EGR is only active at part throttle, low load above about 2.5K RPM.