I have a B18C1 in my 1994 Civic Si.
This swap has been great for years.
Recently I am experiencing a random stumble, or very short loss of power, when under power.
I was just in the distributor, cap and rotor looked normal, wire set is ~1 year old.
No CEL.

Any ideas? What should I look for?

Thank you all for any ideas you may have!

 

Nothing? No ideas?

 

I would try taking a look at your iacv, oftentimes this valve gets clogged and would cause a problem like you mentioned. It's located on the back side of the intake manifold. There's two coolant lines connected to it, and there's 2 12mm bolts that connects to the intake manifold and the plug. Take it off and clean it with throttle body cleaner let it dry and reattach it. You can't break it by cleaning it, so it's worth the effort.

 

Thank you, I will do so as I have it off right now.

I thought it only controlled idle, are you saying it will affect the engine when under load/not at idle?

It does look dirty BTW:

 

I would try and check the iacv had that same problem with my 99 civic si. Took it apart and cleaned it. No problem now. Or maybe your tps made need to be calibrated correctly

 

Well like I said there's no harm cleaning it ,and yes it's job is to keep the car idling properly once the car is warm. But like in my case for some reason say when I I'm in highway speed in 5 gear or what ever gear if my rpms are low and I'm only using like 1/4 throttle it would start to stumble like you said your car does. I'm not saying that the problem with the car but it's worth trying it. Also maybe try checking ur fiTV that might have to be cleaned too. Good luck and lmk if it works or not.

 

Thank you! I hope that does it.

 

I have been reading about the TPS, and how when those go bad they sometimes produce similar symptoms. Hope I do not have to replace!