Carb tuning for high altitude.

[conway]

Hello, I have a 1986 Honda Accord that lived at sea level it's whole life. We just purchased the car and brought it to Denver (5600 ft elavation). The car runs rich.
I've downloaded the shop manual and went through it but can't find any information on the jet sizing or adjustments other than the idle speed.

Can any one help provide more information about air and fuel adjustments, their locations on the factory carb, jet location, parts number for leaner jets or any other information.

I'm not new to tuning carbs, but I've never worked with this honda carb before, and am lacking good support material.

[Oldblueaccord]

Hello, I have a 1986 Honda Accord that lived at sea level it's whole life. We just purchased the car and brought it to Denver (5600 ft elavation). The car runs rich.
I've downloaded the shop manual and went through it but can't find any information on the jet sizing or adjustments other than the idle speed.

Can any one help provide more information about air and fuel adjustments, their locations on the factory carb, jet location, parts number for leaner jets or any other information.

I'm not new to tuning carbs, but I've never worked with this honda carb before, and am lacking good support material.


Picture of the car for reference.


Attachment 7299

Nice looking car.

I do not think there are jets available for our carbs but im sure they sold them at your altitude just not sure what they did to get them to run.

[conway]

The car doesn't run terribly as is. It does however idle rough when warm, has a slight hesitations from 3-4k, and wants to keep going on decel. You can smell it running rich as well.

[conway]

Some one pointed me in this direction:
Is this accurate info? Where some models equipped with this unit?

If it doesn't have the 'ABC' altitude compensator it'll never run right up there. Go pull one from a junk yard. It's a little plastic deal with three adjustments (air leaks) labeled ABC and just plugs into four ports on the car. Easy peasy. Like this but not this.

[Griff]

Here is a pic of the engine bay of my '89 LX. Sorry, it's a bad pic, but I thought you may be able to see if my car has anything yours doesn't. My car has been in Colorado it's whole life. Also, if you need parts, I recommend the u pull and pay at 390 W 66th Way.

[conway]

Does anyone have instructions for testing the altitude compensator?

[Dr_Snooz]

Download the manual if you haven't: https://www.dropbox.com/sh/vtyhl48z5...udl0xk_Oa?dl=0

According to the chart on p. 11-16 of the '89 USDM manual, these cars came with two carbs: California... and everyone else. What you have should be sufficient for where you live, so I'm inclined to believe that you only need to troubleshoot, instead of looking for a different system. The carburetor is discussed in detail in chapter 11 of the manual, so have a look there. There are Symptom-to-System diagnostic charts and extensive troubleshooting flowcharts. You have a myriad of little controls, solenoids, vacuum actuators and the like that combine to make the car run optimally. At this age, they tend to have difficulties, so start by reading up and testing them according to the instructions in the manual. You'll probably be running good in no time.

Let us know what you learn.