What is the problem?

For about a week or so, I had noticed a scratching sort of noise coming
from somewhere under the hood, but was unable to pin-point its location.
There were no changes in engine performance or behavior. One morning,
I was sitting at a stoplight, the engine stumbled very hard, and almost
cut off. The Check-Engine light came on, and idle RPM level returned to
normal. (I also noticed the scratching noise had stopped) Upon trying
to accelerate, I noticed the car would not rev any higher than
3,500RPMs. (This is a classic symptom of the auxillary fuel injector
not working) I checked the ECU and the LED was blinking 16 times, which
corresponds to the "Fuel Injector or Fuel Injector Circuit". I called a
few mechanics that were supposed to be "Honda specialists" and they all
told me to change the throttle body because the Throttle Position Sensor
had gone bad and that is what was causing the Check Engine light to come
on and making the Fuel Injector stop working. I bought a throttle body
from Beaver's Honda (junk yard) for $65 and changed it myself. Now,
when I crank it up, it idles at almost 2,000RPMs. The idle adjuster
screw is all the way out, so that's not causing the high idle speed.
When the accelerator is pressed, I can hear the engine suck in a lot of
air, but instead of revving up, it bogs down, and then back-fires
through the intake. Aside from changing the throttle body, I have not
changed any other parts.

Thanks in advance,

Jonathan

 

you don't say age/model of honda, so using my magical mind reading
powers & the fact that you refer to code 16, i'll conclude it's a
manifestation of a typical symptom of the main relay giving out on a
88-91 civic - which they do all the time. it may indeed be an injector,
but gotta tell ya, it's real rare for honda injectors to fail. you can
therefore conclude that code 16 is a wild goose chase. [needs to be
fixed, but not a cause of this problem.] throttle position sensor is a
crock too. that gives code 8, iirc, and that'll only affect you at
lower revs where the throttle usually sits at highway speed, not idling
at a stop light.

much more common cause of "bogging down" is a problem with the tandem
valve. the auxiliary injector only usually operates for acceleration
enrichment. the engine will idle perfectly as well as run at high rpm
with the auxiliary injector disconnected - if the tandem valve opens
properly. take the top off & look down the throttle body, with the
engine running. then blip the throttle. you can see the auxiliary
squirt if it's working. you'll see if the tandem valve is operating
too. if the tv's not acting snappily, check the vacuum hoses, and the
tandem valve diaphragm for leaks. also check the brake power servo for
vacuum leaks - a sudden surge of excess air kills idling engines easily.

excess idle speed now you've changed the throttle body? again, check
for vacuum leaks. check the idle air control circuit too. should hear
the servo click as you disconnect the power leads.

 

Sorry about not listing my car: 1990 Honda Civic LX, 5-speed, 1.5L
Dual-Point Fuel Injection.

(Good job with the ESP) ;-)

Jonathan

 

Any idea what could have been making that scratching noise? Like I said,
the scratching noise stopped immediately when the problem started.

Thanx for your input, I'll check the main relay & for vacuum leaks.

Jonathan

 

what /sort/ of scratching noise? from where? have you checked the
tandem valve operation yet?