Alright what do you guys think about this problem?

While warming up the R idles, revs and engages just fine. Once I reach operating temps however I have a problem. The problem is a serious sputter. I have done the following evalutions on it:

If gentle pressure is applied to the throttle from idle, the car revs up fine.

If I mash the throttle to the floor from an idle, the idle drops and the car sputters out and will die. Or it will sputter down and then roar to life. The 2 switch on and off.

The problems are consitant if Im in gear moving the car from a start as well as when Im in nuetral.

These problems only occur in the low idle RPM range. Once she gets up in the revs its fine.

The only engine mod I have is a Mugen intake. I thought I might have too much air flow and not enough gas, but this didnt happen when I installed the intake.
I thought it might be the injectors are clogged, but the problem goes away in the higher RPM ranges. I think the problem would be consisant all the way through the range of the injectors were clogged.

I thought it might be my shitty AC relocation, but this didnt happen when I first did that.

Im thinking it has to be an air/fuel mixture just because of how, when and what occurs.

Any thoughts? Any ideas?

 

How many miles on your R? Have you checked your spark plugs? Waiting for the experts to respond..

 

sounds electrical to me, check and or replace plugs, wires, dist cap and rotor. AC relocation would have nothing to do with it. you are not getting a CEL code?

 

could a bad ground cause something like this? I had a similar problem on my B16, checked all kinds of things, but never got it resolved.

what about a fuel filter?

 

A friend of mine had that same problem with his JDM B16. He replaced spark plugs and wires and the air hose that goes to the Fuel Pres Reg and it stopped. The air hose had a bit of a hole it it. That was the very first thing he replaced, and it did get noticable better with just that one thing.

 

I would guess fuel filter, but what do I know.

 

Check your distributor. If you clean the engine bay a lot sometimes water will get in there and cause the bearings to rust, and when they go it acts much like you described. If you see reddish powder inside your cap then you probably need a new distributor. I had the same problem on my old SOHC.