Hi,
I have an 88' accord lx 4 door with manual transmission and 265,000 miles on it that I bought for $50. from a friend for a work beater, it had been rear ended and the idle ran high (2000-2500) after warm-up, but i though what the heck it'll get me around until I find something else. But after having worked on it I reallized that I like that little car and want to keep it, sure it's not pretty, but I like it and spent the money at a u-pull-it to replace the trunk lid and tail lights so it doesn't look that bad. I've been working on cars since I was a teenager, but I don't really know a lot about emissions equipment or how "newer" carbs work.

Anyways, here's what I've done to it and what it's running like,

I cleaned the outside of the carb and particularly the choke mechanism. but also cleaned the inside of the carb as I was doing this, played with the choke but couldn't get it to go down into the normal idle range so I installed a manual choke kit which solved the fast idle problem but I discovered that it idled rough, and has a noisy air suction valve ( it sounds like the check ball is rattling quite a bit) and when driving in 4th or 5th gear down the road if felt and still feels like it is starving for gas when you are just maintaining a speed but when you step further on the gas it responds just fine and has normal pick-up and power. Not expecting to keep the car for more than a few weeks or months I used what I thought was the idle speed adjusting screw on the passenger side of the carb to raise the idle speed to about 1100, it didn't fix the problem but it at least smoothed it out a little and didn't sound so bad. Once again I wasn't planning on having it for very long so please don't judge me too harshly.

I also did a complete tune up including plugs, wires, cap and rotor, air filter, oil and oil filter.

I replaced the valve cover gasket and adjusted the valve lash. I though that maybe an out of adjustment valve might be part of the problem but it made no difference.

after doing these things I took it through smog testing and it wouldn't pass so I did some tweaking to get it to pass then readjusted it to make it drivable and drove it that way for two years. I guess that little car grew on me.

Then last summer the clutch went out and I was unemployed and didn't have the money to pay a mechanic to repair it so it sat until september of this year, I did go out and start it about once a month and let it run for about 1/2 hour or so.

last month I decided to tackle the clutch repair and that went fine, then about a week after that repair I decided to use it to drive around looking for work, on the way home it started stalling when I came to a stop. I felt like it was starving for gas so I used the choke part way to compensate and that worked, and I have had to do so ever since. everytime it gets warm I have to pull the choke out part way to keep the rpms up. when it does die all I have to do to start it is pump the accelerator once and it starts right up but will die again if I don't keep pumping the pedal or choke it.

First thing I did was change both fuel filters.
I did a compression test and the results were 170-180lbs dry and all around 180 lbs wet.
I cleaned up around and in the carb with choke and carb cleaner again.
I checked the fuel bowl viewing window and it appears normal.
I felt around most of the vacuum lines but could not find any leaks or breaks.
Oh, and it now has 292,000 miles

I've seen numerous posts about idle problems and am hoping to figure out what the problem is. Among the possibilities i've read in other posts are:

The PCV valve
The EGR valve
The dashpot
Fast idle valve
Idle control valve
slow mixture solenoid
Idle adjusting screw on back of carb
checking all vacuum lines to and from carb
checking intake gasket for vacuum leak
checking the carb base for a vacuum leak
clean out the carb jets
check fuel bowl level window

Any suggestions where I should start?

 

I think that you should focus on the carb. I have zero experience on them. You can download an 86-89 shop manual. It can be found in the spooner link I posted in the Online Manuals thread in the DIY section.

The carb has several controls, and there will be some tests to figure out what is causing your car to run poorly.

 

In my experience you fix the items you know are issues and that gives you more information or fixes the problem. Without the manual choke does it open correctly? It should be shut when cold than open slightly after starting and later fully open. Does the engine at idle surge (RPM goes up and down)? Does putting a rag over the carb(choke) when warmed up and running smooth it out of make it worse? After you shut it off when looking down the carb is there smoke. What is the exhaust color of smoke? Did you check the EGR and the port that it sits on for carbon build up? What is the color of the electrode on the spark plug? There are certain items on the Honda Carb that you should never adjust but it has been a long time. I think they were paint marked from the factory.

 

Thanks guys, I downloaded the manual and printed out a few things and will try your other suggestions today.

Thanks

 

I was to trying to determine if you have an engine miss along with the choke problem or something affecting all the cylinders such as the carb. That is why I was asking if the idle surges. I can tell a miss vs something global driving the vehicle but it is hard to explain. I don’t remember what Honda used in there choke system for that year but there should be some clues in it not working properly. I think it used the engine coolant to heat it. Starting out I worked in a small garage and occasionally my old boss would install a manual choke on a vehicle rather than fix why the choke was not getting the proper heat to open it. Not one time did this make the vehicle more drivable. This was the old American cars that had a port in the intake and used exhaust gases to heat it up. The port would clog up with carbon and not heat up the fuel mixture and was part of the design. I would start with the choke problem.

 

That makes sense, I'll look to see what type of auto choke it was while I'm checking out the EGR. Yes it does surge, Does surging indicate something specific?

Thanks Chris

 

O.k. , I checked the EGR and it looks like it's working, in other words when I suck on the end of the vac line going to it the plunger moves.

Next, I looked at the choke and it has two vac lines that go to a diaphragm on the back side of that whole mechanism, plus it had a single wire that did go to the choke before I installed the manual choke cable.

Then I decided to check the vac diaphragms on the distributer and one of them marked number 2 would not hold vacuum when I sucked on it and put my tongue over the end, by the way it felt it has a small leak in it as it wouldn't hold vacuum and I could draw air through it at a slow steady rate.

I plan on getting another can of choke and carb cleaner to spray around and look further for vacuum leaks.

or is there something else that I should check first?

Please keep the ideas coming guys, I'm all ears.

 

"Does surging indicate something specific"

Yes it sure does. The problem should be an Air fuel mixture problem. You vehicle is either running to rich or too lean. If you put a rag over the carb when it is running too lean the rpms will climb and too rich the engine will be unhappy. To lean is too much air look for vacuum leaks.

Take the EGR off and see if the valve is not closing correctly and if the port on the manifold is carboned up.

You described an electric choke see if it has voltage to the wire going to it while running.

 

I removed and cleaned the EGR and re-installed it with a new gasket, no change, next I put a rag over the primary bore of the carb and the rpm's picked right up and smothed out, so I sprayed carb cleaner all aroung the intake manifold, carb and carb base, and all of the vac lines, no change in the idle, still rough, still surging, and trying to die. I decided to try pinching the vac lines coming out of the carb with needle nose pliers one at a time, no change.

I checked the wire that did go to the auto choke before I installed the manual choke and when warm it has voltage.

 

From your information with no vacuum leaks you need to do some work on the carb and I think there is a special tool you need to adjust the mixture when you are done. Honda used to and probably still does sell the parts you need to repair it on the car with just taking off the top. From what I remember you take the top off of the carb and remove the serviceable parts and spay carb cleaner into the orifices and the parts you removed if reusing. You have to set float levels and I don’t remember if your carb has sight glasses. If you have proper voltage to the choke then you need to replace the choke element. It has been a long time since even seeing a carb so this is to the best of my memory but you verify that your car’s mixture is getting to much air. The last time I would recommend before doing the carb is checking your ignition timing as that will affect the mixture in some cases.

Last there is a small chance you will need to take the carb off and remove the moisture screw and clean out the orifice.