'92 Civic DX Hatchback Idle dropout problem

I just had some major work done on my '92 Civic DX Hatchback
(automatic transmission, A/C, NOT a VTEC, the regular engine) at my
local Honda dealership. Car had been running well. Have ~85,000 miles
(I'd don't drive much). Now I have a very frustrating idle problem
(the engine randomly almost dies) that no one can figure out. Here's
the story:

1. In May, the engine began sputtering occasionally at stoplights,
especially when trying to accelerate from a stop. Led to a few close
calls with oncoming traffic, as the engine almost died mid-
intersection.
2. After this happened ~3 times over ~3 days, the engine just died,
wouldn't restart (cranked OK), & had to be towed to Honda dealer.
3. Codes revealed a faulty Idle Air Control Valve (IACV), which was
stuck shut. IACV was therefore replaced.
4. Also had other major maintenance performed (it was time anyway):
90,000 mile service, including Valve Clearance Adjustment, timing
belt, water pump, new plugs & air filter.

Now the trouble really began...

5. Car didn't perform well at highway speeds (hard to quantify, but
engine just seemed louder & less powerful at high speeds, ~80 mph).
ALSO, at idle, in gear, at a stop, idled roughly, and it seems like
the motor is cutting off for a split second. Almost dies, then
recovers. Seems to happen more when it is warmer out (~75-80 oF).
Rarely happens if either the car is in Park/Neutral, or if the A/C is
on, or if you're actually moving.
6. First the dealer's mechanics couldn't observe the idle problem,
then didn't believe it was an issue, then asked if I was sure it
wasn't happening before I brought the car in the first time, etc. They
also said that the IACV had an "adjusting screw" that was improperly
adjusted, and that it was now adj. properly. (Next time, I was told
that the IACV does not have any adj. screw!!) Did NOT fix the idle
problem.
7. Back again to dealer. Service manager is trying his best, and
replaced the PCV valve and its hose. No change in idle problem.
8. Back again. Manager discovered that the valve clearance had been
adj. too loose, and timing was 5 degrees retarded. Fixed the
clearance, rechecked timing, idle speed, etc. Also cleaned out the
throttle body (they said it had some carbon buildup). All this now
seemed at last to improve the high speed driveability somewhat.
Possible improvement in the idle problem (seems less frequent), but
still not gone.
9. Now, the idle dropout happens like this:
a. Car is idling, and fan comes on. This kicks up the idle speed a
bit.
b. Fan shuts off. After ~7 seconds, idle speed drops back down.
c. After ~20-25 seconds more, engine drops out...idle speed for that
split second makes like it is trying to go to zero.
d. Cycle of a, b, c repeats (for as long as you're willing to sit
and wait).

The specific timing of the problem described #9 makes me think it is
unlikely to be plugs, SP wires, rotor, cap, etc. (Wires & cap were
replaced ~2 yrs ago (non-Honda).) Coolant-temperature related? Some
other kind of sensor? What else could it be? A faulty, new IACV? Other
things I've seen mentioned: coolant temp. sensor; Throttle Position
Sensor, coil, igniter, SP-etc..

Sorry to be so long-winded, but figured I'd give you experts all the
info I have.

Desperate for help!! Thanks!!!

 

wrote:
<snip>
get to the point - i'm not paid for this. 3 lines or less - what's the
problem?

 

Idle drops out:
a. Car is idling OK, fan comes on, idle speed increases a bit.
b. Fan shuts off. After ~7 seconds, idle speed drops back down.
c. After ~20-25 seconds more, engine drops out...idle speed for a
split second goes to zero.
d. a, b, c repeats endlessly

 

thank you.

1. check the coolant level in the radiator when cold - [never rely on
the expansion bottle level to tell you because if there's an air leak,
the level never changes.]

2. if the above is ok, check the idle control circuit. disconnect the
i.a.c.v. when warm and see what happens to engine revs. if the engine
dies, you need to set the idle correctly. and before you do that, you
need to check everything else is set right like timing, valve lash, etc.
when you've prepared everything else sufficiently, remove the iacv and
check the filter screen is not clogged. carburettor cleaner and a q-tip
work great for that.

3. check for error codes on the computer as well!

a great thing to buy for your honda is the factory service manual from
helminc.com. full diagnostic flowcharts for every system on the vehicle.

 

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The dealer sounds like a dope. Fill the reservoir to =MAX= and check if
the rad is full to the top. (this is in your owner's manual). If the
coolant level drops next day, you had AIR in the system. It can screw up
LOTS of things on all Hondas.

Look at the adjustment slot on your upper distributor bolt and see if
it's set near the center, or has somebody cranked it all the way to one
end of the slot? If so, they probably got the Timing belt off by one
tooth and tried to correct by changing the ignition timing.

Report back.

'Curly'

 

motsco/Curly, Jim Beam: Check coolant, reservoir
Radiator is full when engine is cold, reservoir ~1/2+ full. Did of
course get coolant flush because of water pump repl. w/ T-belt
service. Will a careful re-flush eliminate possible bubbles?

See about 3 mm of slot showing past the large washer. Gap is toward
rear of engine, i.e. looks like bolt is toward front end of of range,
but I can't quite tell how far to end of range (no personal
experience). Do you think this is near end of range? Can also see old
marking from washer visible on dist. case at rear of range. So, set
wrong now, and possibly before as well? Should it be ~in the middle?
If so, should I take it back to dealer and ask that they move T-belt
by one tooth in correct direction, then re-do timing, idle adj.?
Anything else?

Haven't done the IACV check yet (will try tomorrow). Presumably dealer
saw no other codes other than orig. IACV problem? I don't have code-
checking equip.

Thanks guys

 

no. the fact that you've recently done the timing belt leads me to
suspect the belt's slipped a tooth. very common for the belt not to be
tensioned right. google this group for procedure or check the book.

bolt should be about the middle of the slot like curly says. see above.

seriously consider finding another dealer to do this work. these guys
don't seem like they know their business.

 

Thanks very much, will press dealer to fix their mistakes, and then
find a new dealer!

Last thoughts/questions: Is it clear that the mis-set T-belt, and thus
the mis-adj. distributor/timing, is the cause of the idle drop-out? or
is it a contributing factor, along with possible air bubbles in
coolant lines near IACV, or some other cause? I feel a bit like we set
out to drain the swamp but are currently wrestling w/ the alligators!

 

------------------------------------

It would be nice if you knew somebody handy enough to slip off the valve
cover and confirm whether the TB is out one tooth. I can't say for sure
how hard it is to check on your engine.
The TB can be 'out' just because of carelesness when installing it, not
necessarily because it's loose. Changing the angle of the distributor is
the 'patch', and should have confirmed to the tech that he did the belt
wrong. :-( As far as I know, the ignition timing should never need to be
changed more than a degree or two over the life of the car, unless
there's some 'tuning' going on.

If you have access to a Haynes or Chilton's, the procedure for checking
the TB alignment will be in there.

Search at www.tegger.com to learn whether it's necessary to bleed any
trapped air from your '92. As was mentioned, later models don't need it
and their (reservoir) coolant level stays rock-steady summer and winter,
hot or cold.

'Curly'

 

It would be nice if you knew somebody handy enough to slip off the valve

I can take off the valve cover no problem. Looked at the link you
suggested and found this one -- http://timingbelt.soben.com/ -- that
gave pictures from an Acura T-belt replacement. BUT, it's not clear to
me just what one does/looks for to determine whether T-belt is off by
one tooth. Could you please supply a bit more detail? I assume you
take off the valve cover, turn engine (by hand?) until cylinder 1 (the
one next to T-belt?) is at TDC (judged how?), then look at where belt
lines up with some marking on case? Sounds like a quick job if you
know what you're doing/looking for?

Thanks!

 

That's pretty much it. The crank is turned *counterclockwise* by the bolt
head (supposed to be retorqued after doing this but in practice it won't
budge even when we desperately want it to) or by a strap wrench on the crank
pulley until the TDC timing mark lines up. Note: most engines turn
clockwise, Honda engines turn counterclockwise. Never turn the engine
backward as the timing belt tension is on the wrong side and the belt might
skip. Anyway, the cam gears should then be in the TDC position or exactly
180 degrees away from TDC. There are stamped markings or holes of various
sorts for the various engines. Most of them are obvious enough to figure
out, but a few are not so obvious. Any shop manual for your model, even
Chilton's or Haynes, will have the details.

Mike

 

disconnect the i.a.c.v. when warm and see what happens to engine revs. if the engine
dies, you need to set the idle correctly.

Indeed, engine dies immediately. Should it idle at all w/o IACV
connected (if so, what extra thing does the IACV do?)?

 

when fully warm, it should idle a bit below normal, but not die. but
before you adjust anything there, make sure it's not timing, ignition, etc.

 

disconnect the i.a.c.v. when warm and see what happens to engine revs. if the engine dies, you need to set the idle correctly.

OK, thanks, will twiddle the idle knob and try again, after I'm sure T-
belt is OK.

Got valve & top T-belt covers off. Can see UP marked on camshaft
pully, and a line mark that looks like, if UP were up, would align w/
a little pointy thing on lower (plastic) cover. Mark & point should
line up, then cams will all be at TDC if T-belt is OK, otherwise some
cams will be off? Do I need to get the bottom cover off, to see the
lower two T-belt pulleys? (I think doing so it beyond my skill: too
many other pulleys, engine mount, etc there.) I guess what's confusing
me is that the T-belt camshaft pulley is physically part of the
camshaft, so how can it be anything but lined up (UP=up, mark=pointer,
+/-TDC on cams)? I'm clearly missing something (those lower two
pulleys??)

 

there's two sets of marks on the crank pulley - one [or 3 close
together] for 18 degrees, the ignition timing mark, and one for tdc.
it's the latter you need at the pointer when doing cam timing.

for the cam pulley, there's two sets of marks. you need to check which
is which for the ex, but one set should be parallel with the head top
and "up" showing. the other gets pointed at a different mark on the
head. it'll be one or the other.

again, you really need the book on this.

getting back to the idle, you should /not/ adjust it until you have
everything else set right.

 

and you should check belt tension since you have the cover off!

 

Cam pulley is the one at top, right?, and crank pulley is down & back,
where I can't really get at it w/o taking apart the engine mount, etc?
(What's the third pulley for?) Tension seemed tight (hard to push belt
w/ my finger in ~3 mm).

 

dude, you /really/ need to buy the book!!!

crank is at the bottom. easily accessed via the wheel well. leave
mount alone unless removing belt. should be able to show more than 3mm
of belt with the cover removed.

 

OK! Wasted enough of all you guy's time, thanks. Will get the book and
have a look. Thanks again!!

 

Checked T-belt position on cam & crank pulleys. W/ cam pulley at its
mark, crank is ~10 degrees past TDC (single mark for TDC, and 3 timing
marks at 14, 16, 18 deg. BTDC). With crank at TDC, cam is ~1 tooth
before its mark. Cam pulley has 38 teeth, i.e. ~9.5 deg./tooth. Thus,
T-belt is off by one tooth.

You would think when you pay professionals a good chunk of change to
do the job right, they would! Have they no pride??

Now one of my 3 belts on the crank pulley is squeaking a bit. (I had
to work the belts off to see the marks on the pulley.) I assume it
can wait until the car goes back for the T-belt (& distributor, and
coolant-reflush, and idle speed adj.), I hope tomorrow?