Hondas06

Yes, I started a new thread for the same car and problem, and I apologize in advance for doing so. Perhaps I was a little too detailed in the previous post. This said I'm reducing this down to its simplest elements and trying it again.

It's actually a pretty nice looking car, and other than a miss/pop out the tailpipe until turning the a/c on and it running a little rich, it runs great. Heckuva good sounding engine!

The problem is: I can't figure a couple things out

1) What would cause the car to miss/pop from the tailpipe, but as soon as I turn on the a/c the miss/pop goes away and it runs smooth? If you had this problem with your rex what you replace, and why? Does this sound like an electrical or ground "bleed-over" issue to you or something more mechanical?

2) Why will the car not go in to timing set mode, and why does the CEL not turn on when I connect the service check connector?

3) Since some sticky-fingered loser jacked my Honda FSM's.....what a lout...... so can someone come up with a diagnostic flow chart, pictures or something to aid in my diagnosing these issues?

I'm a 20-year experienced import mechanic feeling pretty darn stupid right about now. I admit it, I am stumped, lost, scratching my dome bald and losing my patience. I've never lost to a car in a diagnostic contest and am trying with everything I know to not lose.....however......I can do without this headache.

This project is now equivalent to being on life support, and I'm fixin to pull the plug. So before this thing winds up on my tow dollie behind my Land Cruiser en route to the smasher I'm asking for any help and hoping maybe someone has seen this before. Maybe you're a "super tech", cape and all and you'll help rescue me from this hell I'm in? Maybe you're just a weekend warrior and you bagged this problem already? So how about it.....can anyone help a brotha out here? Anything?

You know, sometimes fixin' a car is like a case of the clap......you might get one that's hard to get rid of!

Sorry to sound like such a whiney biatch , but I'm bent and spent . Thanks for any help....and letting me vent.

1990edsedan

http://hondatech.info/downloads/Auto/Manuals/Civic/ <---go get your manual there.

Hondas06

Okay....NOW i'm on the right track. The patient has revived and is off life support!

With emissions diagnosis I always start with the ABC's:

A = Alternator; is it functioning properly? If so what is the condition of the:
B = Battery; is it properly charged? If so how are the:
C = Connections; to the battery, grounds, plugs on wiring harness, terminals, things that
make connections from a secondary signal i.e. starter, relays etc. If so how is the:
D = Distributor; or ignition distribution system? Are all components (coil, electronics,
cap, rotor, wires, boots, plugs etc.) correct, timed, clean and in good shape? If so
how is the:
E = Engine timing: Is the red mark on the pointer and the cam sprocket on the marks?

If you caught that, the red mark on the pointer and cam alignment at the same time?

THE WHITE MARK IS TOP DEAD CENTER, NOT the red mark. Too bad I didn't remember that when I checked it. Chrimeny......how stupid to forget something so simple.

So went to line it up, and the tensioner bolt is overtorqued and rounded off. Thankfully I brought my "A" game today (finally) and managed to still get it timed right.

NOW with the engine properly timed........and a bath to wipe the egg off my face the car is FINALLY running way better......but still has a very slight sputter/miss at idle (which is now about 700) that goes away with electrical load and a/c on. The only difference now: Turn on the a/c and the idle goes up, turn on the headlights or other electrical load and the idle goes down. o2 volts hover mainly between .23 and .57. Idle quality improves when the fuel return hose is slightly restricted and o2 volts respond, hovering around the .5 range if I get the amount of restriction right.

I do not think its a fuel pressure regulator. Here's why: Sometimes the idle quality changes/improves and o2 volts stabilize around .45 to .69 after electrical load is removed, like after the cooling fan or headlights shut off.

With the air intake hose removed, I unplug the EACV and there is still vacuum present at the EACV port in the throttle body. Completely obstruct this passage and the car dies. Idle set screw has been turned/adjusted while vacuum is present at the EACV port with it unhooked.

Rapidly plugging and unplugging the EACV key on engine off: initially one click (more like a "tick") is heard but after plugging/unplugging it rapidly 15-20 times two much louder clicks are heard. I removed the EACV and confirmed limited pintle movement when one click/tick is heard and greater pintle movement when the two clicks are heard. Re-install EACV, re-attach plug, start car, let run for one second, shut off, rapidly plug and unplug the EACV and sound cycle repeats. There is no filter screen on the EACV.

So now the questions are: When the EACV is unplugged should there be any vacuum present at the EACV port in the throttle body?

Do the sounds heard above indicate the EACV is sticking?

It's my understanding the EACV operates by means of a rapid ground pulse. The faster the pulse, the more it opens, the slower the pulse the less it opens.

It seems to me the EACV is bad. I'm thinking the a/c on results in greater electrical load, therefore a more rapid pulse meaning the EACV should move more to compensate, but when a lesser load is applied it doesn't have to move as far, and because of an internal failure it doesn't move well when a slower pulse is applied?

What do you think, do I finally have the answer, a bad EACV?

OneBadTurboCRV

So I see you left out details in your other thread... and what happened to keeping this post "KISS"?

I somewhat could see the IACV - but... Most of the time it's fluctuating idle, high idle, or low idle... have you cleaned it? Swap it out wit a junk yard one...

Hondas06

Looks like I "kiss"ed that goodbye.....EACV is clean, but no filter screen present. It does idle low when the headlights are on.