Hi, I'm hoping someone can help me with a problem on my 84 accord. It has 160,000
mi.

Now that the weather is turning cold, I have an interesting problem. On cold (usually
low 40s to hight 30s) damp mornings I go start the car to go to work. It starts right
up. I scrape the ice off the windows, and head off to work. It's about 2 mi. to the
entrence to the interstate. Everything running fine. Now about 8 to 10 minutes after
starting the car and the temp gauge indicates that the engine has finally come up to
operating temp. Then the eng. will start to miss fire and loose power. I'll be doing
65-70 mph when this starts. It will get worse, and the car will loose speed. When I
get down to 45mph, I'm looking to get off the interstate.

Sometimes, the car will stall other times it keeps running. Regardless, I site in a
parking lot, or on the side of the road for about 3 to 5 minutes. If the engine kept
running, I can goose the accelerator and hear/feel the misfire. After the 3 to 5
minutes, it will clear up and the eng. will rev. nicely. (In the case of it stalling - it
will now restart). Then I can continue the drive to work without further problems.
This started last winter and only happen about 6 times. So far this winter, it's
happened 4 times a the last 2 months.

Anyone got any ideas?

TIA

John

 

Carbureted?
Smell of raw gas?
Do this in the summer?
use any oil?
Soot out exhaust pipe?

Fuel delivery problem.......
Possible time to replace fuel filter?
Fouled Spark Plug?

As you come back with some answers to my first questions, I may be able to be more difinitive on where we've got to go with this.
P

 

Carbureted? - YES
Smell of raw gas? - NO
Do this in the summer? - NO
use any oil? - NO - less than1/2 quart in 3,000 mi between oil changes
Soot out exhaust pipe? - No

>Fuel delivery problem.......
>Possible time to replace fuel filter?
>Fouled Spark Plug?

I replaced the pump and filters about 2 yrs ago. This only happens on cold, damp
days. Mostly in the morning. I can't remember it happening on the drive home.

John

 

I beleive you might have one vacuum hose damaged Check out 3geez.com

 

We can eliminate the Carburetor Flooding or running extremely rich from the equation (No soot or Raw Gas Odor). And it appears that the choke function (cold auto-rich system) is working correctly.
We can more than likely eliminate the ignition as a source of the problem; The Ignition System would most likely act up while it was stone cold and damp, rather than after it had warmed up.
Which leaves things such as the evaporative control system, EGR and such.
I've an additional question:

Is this consistent enough that you can "plan" for it to happen?

P

 

make sure the hot air door in the air cleaner is working properly ,,if it is open to cold air,when it is cold and hwy driving what will happen is carburator icing.. ,,it will make car miss badly on hwy driving ...there should be a tube coming from the exh manifold into the air cleaner make sure that door in the air cleaner is open to the heat and not the cold temp coming in...

 

Sorry DH, I KNOW what you're gonna say but I gotta ask: Carb Icing in Arizona?
LOL

Real early morning Regards

P

 

deserthonda & P_Adams, I think you both might be right Carb icing.
This is what I thought, but I didn't want to bias anyones thinking.

Not it doesn't occur with any regularity. This morning it was 39 but clear and
dry. No problem. On days that it's foggy, misting, or raining and in the
30s or 40s is when it happens.

Yesterday, I went out and put a vac gague on the vac. motor that opens
and close the hot air door. I'm only seeing about 2" of vac. Not very much,
but I can't find much in the Honda Shop manual (the actual shop manual - not
a haynes, etc.) about how much vac. it should have. Only one picture of a
vac gauge and the word 4" in the caption.

Yes, the hose from the heat stove to the bottom of the snorkle is there and I
don't see any major holes or tears in it.

I also removed the vac. motor and connected the vac line to it. It very, very
slowly pulled the plunger in, with no load. I've tried to feel if it is lifting the door,
but I can really feel it from the front of the snorkle. I pulled the hot air hose from
the bottom of the snorkle, and can't get my finger in there to feel either. Tried
to see it with a mirror and flash light, again - no go.

I guess I could pull the air filter enclosure off and see if I can't see it working
then.


Now let's assume that it is carb icing and associated with the hot air door.

1. How much vac. does it take to open the door?
2. My guess is that the door is closing too early. How can we test it, or keep it
open longer? - tie a string to it and manually try and open it

John

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P_Adams &raquo;</TD></TR><TR><TD CLASS="quote">Sorry DH, I KNOW what you're gonna say but I gotta ask: Carb Icing in Arizona?
LOL

Real early morning Regards

P</TD></TR></TABLE>

Not in AZ ole pal..but i used to live and work in Wisconsin and that,s where i saw it happen more than once

 

Do either of you know how much vac. is supposed to be at the vac. motor to lift
the hot air door? Is 2" enough?

Any ideas if it is closing too early and why?

John

 

hook up a vacc pump at diaphram and pump it up see if it holds vacc... you should have more than 2" of vacc there, i cannot remember what controls vacc there it has been a long while since i worked on that issue , u might have to find a different source of vacc and splice into it ...

 

Thanks. I will check it out.

I really appreciate the help you and P_Adams have given. I hope I didn't p!$$ you
all off by not telling you what I thought it was at first. But as I said, I didn't want
to bias anyone and I really had no proof other that people with British cars reporting
the same symptoms. The general responce to them was carb. icing. So I figured,
that sounded good. Never experienced it with any of the cars I've owned before.
I've had this car since new, and it just started doing this last year.

Now I understand more about what I was reading in the manuals also. It's all starting
to make sense now.

Thanks again.

John

 

Hey, there's no penalty for Independent Thinking around here.

I sometimes will allude to the answer, rather than offer it, so as to get others' gray matter working.
It makes for better car owners and stimulates out-of-box thinking.

Glad we both could help

P

 

Thought I'd report back. Just finished fixing it - I think. Won't know until the next
cold damp day, but I'm about 99% sure.

I pulled the air cleaner housing off, and started the car. The hot air door didn't open.
So I removed the check valve and connected the vac. lines together and the door
opened and I had about 18" of vac.

That left either the bleed valve or the check valve. I was going to try and
disconnect the vac line going to the bleed valve and cap it, but I couldn't get the
line to pull off. So I disconnected all the vac. lines and took the housing off and
into the garage. While inspecting the bleed valve and the check valve, I noticed
a hole in the vac. line going to the bleed valve. I replaced the piece of vac hose,
reattached everything to the car. Now when I start it the hot air door opens!

Thanks again for the reinforcement.

John