Hey guys - Just got done restoring my R. The only thing I changed on the motor is a Comp twin disc (as oppose to the Comp stage 5 I had before). Motor never came apart during resto. Just the clutch is all that changed.

Now, when I start it, or anytime I'm sitting still it will idle fine. But if I'm driving and then throw it in neutral as I pull to a stop sign/red light, it will surge from 500 rpms to 2000 rpms relentlessly.

I tried popping the gas pedal to get it to calm down and it doesn't work. Once I stop rolling, it calms down.

I doubt it's a vacuum leak. Most the lines are new and I was pretty thorough putting it back together. Doubt it's the IAC since it idles fine at a stop.

Could the different clutch/flywheel weight be impacting it this much? Any thoughts? I e-mailed my tuner as well trying to get his advice.

 

What happens if its in gear and clutch pedal pushed in when you engine brake to a stop/red light? does it still surge? i highly doubt the cluch replacment has anything to do with the engine surging from 500 rpm up to 2000 rpm.

Did you touch anything else you cant think of like any plugs ect ground wires.

does only the tach needle move from 500 rpm to 2000rpm or is it the engine itself reving/surging?

 

DFCO
decel fuel cut off


What ems?

 

Hondata S300.

The motor actually surges regardless of if it's in gear or not while coasting with the clutch in, and then once I'm stopped, it idles fine.

It's very weird. Nothing else I can think of. All grounds are pretty much the same. I know both the IAC and intake air temp sensor have the same plug, but I'd imagine if I reversed them by accident (which I'm nearly 100% sure I didn't), it wouldn't idle and run as well as it does.

This decel fuel cut off...any advice or is it something my tuner needs to adjust for me. I have the Hondata S300 on my laptop so I can adjust the boost by gear when I want, when radiator fan engages, etc, but I haven't gotten too serious into any other parameters.

 

Mmmm i forgot if s300 has it or not

It surges if its in gear? Boost/vac leak.

Your iacv must be compensating for it at idle. Once the car is moving and above a certain rpm the iacv is off

To test for a leak real quick hold your hand over the turbo and if the motor dies you dont have a leak.

If the motor still runs listen for where the "hissing" sound is coming from and fix it

 

Not in gear. I'll be rolling at 40 mph, see a redlight ahead, throw the clutch in, shift into neutral, clutch out and then coast and that's what it'll start surging. Essentially, while I'm in neutral (regardless of if I'm in a gear with the clutch in, or neutral with clutch out) and moving, it'll surge.

I'll check again for a vac leak.

 

Fast idle setting is probably putting you in an area of the map your going rich and or lean so it starts searching aka surging around as it goes rich lean rich lean. Easy to fix

 

Yea, got some good advice from another member I'm going to try on Monday and then I'm also going to datalog a few minutes of driving and send to my tuner and let him take a look. I'd imagine this is something pretty simple. Keep you guys posted. Thanks again for the thoughts.