I got the car about 8 months ago.

91 CRX Si with a B16A.

Replaced all of the normal stuff (plugs cap rotor wires (distributor), fuel filter, oil change coolant flush, thermostat.)

All that junk.

Car runs fine when warm and driven for about 20 minuites. But still has a slight miss, I can see the tach bump up and down about 100-50rmp and can slightly feel it miss. and I can hear it miss if I am behind the car.

Its bad when I first start it. like jums 500rpm.

I know its not a ignition problem, everything has been replaced.

So I am starting to think maybe a bad injector?

The head was just rebuild 6000miles ago.

Any ideas?

Is this common?

I just want it to run smooth at idle!

 

sparkplugs gaped correctly?

 

Yep .044mm, right?

 

The distributor I had was bad (bearings were going out on it), and it was leaking, and causing it to miss really bad.

So I replaced it with a used one, and it stoped missing as bad as it use to.

But still misses.

Im going outside to take a video of what its doing, ill post it asap.

 

do you think you may have changed the timing through the dizzy?

 

it could be one of the sensors misreading
_or_
one of controls that changes fuel mixture when the engine is cold could be dirty or sticking slightly

 

....... Ok. ? No offence but do you know what you are talking about?

Please explaine what "control that changes the fuel mixture when cold" you are talking about?

Are you talking about the IACV? it is fine, my idle is fine...

The engine is missing.

Normal motor - daaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Mine - daaaaaaaaaaaaaaaaaaadaaaaaaaaaaaaaaaaaaaaaaaaaadaa daaaaa

And when it misses, it only drops 100rpm at the max. I would say 20-100 RPM.

Can a bad injector cause this?

 

Oh, important thing I forgot to mention. (sorry)

when I changed the plugs, I noticed the #4 electrode had a greenish tint to it?

My buddy said thats from getting hot, he said it could be leaning out on that cylender.

That is why I suspect a bad injector.

But I can hold a screwdriver up to the #4 when its running and can hear it clicking jst like the others...

 

So, it's missing and drops 100-150 rpms even when warmed up. (Don't just replace everything you think might be the problem. Diagnose the real problem and fix that.)

Could be the #4 injector. (there are places that rebuild/repair/remanufactor injectors and match the calibration for all injectors)

But, the engine is controlled by the car's computer and the computer expects the info from the sensors to be real/true.

What happens if a sensor malfunctions, the wiring connecting a sensor to the cpu opens/shorts intermittantly, or the ground connection to a sensor intermittantly goes out?

Answer: the cpu gets garbage and acts on it causing all kinds of gremlins.

 

k, well, I ordered new injectors yesterday, so they should be here sometime next week.

See if that solves my problem... I took a look at them, and they dont look that great, 2 of them had small airline cracks in the tip, and they were all really loud when they were operating...

I didnt just get injectors to possibly solve my problem, more or less, for peace of mind...