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-   -   Installed new carb insulator= slightly higher idle? (https://www.fuelly.com/forums/f11/installed-new-carb-insulator-slightly-higher-idle-12860.html)

GasSavers_Erik 08-22-2010 12:03 PM

Re: Installed new carb insulator= slightly higher idle?
 
The sensor on the air cleaner just tells the primitive control box whether the air coming through the air intake is above or below a certain temp. It is a switch that is either closed or open- it doesn't have variable resistance like the newer cars.

It is very common for the rubber to fail and for it to flop around loosely in the hole. I sealed mine in with some silicone caulk, but I doubt that it is the source of your idle problem.

Also check your choke butterfly to see that it is opening fully as the engine warms up.

Sport/Truck 08-22-2010 05:56 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Erik (Post 154169)
The 87 carbed civic (I drive one) has a primitive electronic control box that uses solenoids to control vacuum bleeds according to engine temp, speed, oxygen sensor values etc. There are no trouble codes that can be accessed or that are even stored by the electronic control box.

The best you can do is monitor the oxygen sensor output with a digital voltmeter and see if it averages out to 400-500 milivolts (it normally jumps around above and below these values as the air bleeds try to lean it out when it gets too rich).

You can get a universal 1 wire oxygen sensor for it at many auto parts stores and splice it into the factory wire using the materials included with the sensor (heat shrink tubing is included with the sensor)- So you just cut the wire/connector off the old sensor and add it to the new one.

The fuel injected civics/crx's of the 1984-1987 generation do have a computer that stores codes that can be retrieved.

If you have air conditioning, there is a vacuum operated idle up mechanism that bumps you up to a fast idle when the AC compressor kicks on. It is on the drivers side of the carb, toward the back. It may be bumping up your idle.

As you have noticed, there are 50+ vacuum hoses- if any of them has an intermittent leak, it can cause problems like you are describing.

Also check the fuel level in the carb- if the float level is changing because of a bad float valve, the idle speed will change too. You can check the fuel level by looking through the sight glass on the drivers side of the carb while the engine is running.


Thanks Erik, I knew about you having a civic like mine. During all my searches I read lots of post from you (and others) here and knew this was going to be my forum for the Honda.

I'll check the float tomorrow. AFA the o2, do you have any brand recommendations/ PN#'s?

I'm thinking of removing the air cleaner and using a dryer vent pipe or pvc to make a stack to allow me to spray carb cleaner or propane all around the carb. I'm thinking I'll move hoses around during this process to find any faulty hoses. This isn't quite possible with the air cleaner on. What to you think of this idea?

Sport/Truck 08-22-2010 05:59 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Erik (Post 154170)
The sensor on the air cleaner just tells the primitive control box whether the air coming through the air intake is above or below a certain temp. It is a switch that is either closed or open- it doesn't have variable resistance like the newer cars.

It is very common for the rubber to fail and for it to flop around loosely in the hole. I sealed mine in with some silicone caulk, but I doubt that it is the source of your idle problem.

Also check your choke butterfly to see that it is opening fully as the engine warms up.

Should I bother ordering another one?
Yes, the choke works awesome and does fully open.

How do I add a sig line?

GasSavers_Erik 08-22-2010 06:02 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Sport/Truck (Post 154173)
Should I bother ordering another one?
Yes, the choke works awesome and does fully open.

No- there is no need to get a new air cleaner temp sensor- I don't think that is the problem.

GasSavers_Erik 08-22-2010 06:08 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Sport/Truck (Post 154172)
Thanks Erik, I knew about you having a civic like mine. During all my searches I read lots of post from you (and others) here and knew this was going to be my forum for the Honda.

I'll check the float tomorrow. AFA the o2, do you have any brand recommendations/ PN#'s?

I'm thinking of removing the air cleaner and using a dryer vent pipe or pvc to make a stack to allow me to spray carb cleaner or propane all around the carb. I'm thinking I'll move hoses around during this process to find any faulty hoses. This isn't quite possible with the air cleaner on. What to you think of this idea?

I think that bosch makes a universal o2 sensor- just go to the autozone or advance auto website and do a part search.

You could just remove the air cleaner and temporarily plug the hoses going to it or buy extra vacuum tubing and extend them so that they can remain attached when the air cleaner is removed. The hoses that attach to the air cleaner just attach to temp sensing vacuum valves so it is no big deal if you plug them.

You can view the 87 civic factory service manual (including the emission controls section) at redpepperracing.com

Sport/Truck 08-22-2010 06:17 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Erik (Post 154175)
I think that bosch makes a universal o2 sensor- just go to the autozone or advance auto website and do a part search.

You could just remove the air cleaner and temporarily plug the hoses going to it or buy extra vacuum tubing and extend them so that they can remain attached when the air cleaner is removed. The hoses that attach to the air cleaner just attach to temp sensing vacuum valves so it is no big deal if you plug them.

You can view the 87 civic factory service manual (including the emission controls section) at redpepperracing.com

My concern was the spray getting into the carb and thinking there was a vacuum leak. That's the only reason for the dryer vent, just to raise it high enough to prevent that during my testing.

One thought though. The electric solenoid on the back of the carb. Could this be the problem, and how do I check it?

Sport/Truck 08-22-2010 06:20 PM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Erik (Post 154175)
I think that bosch makes a universal o2 sensor- just go to the autozone or advance auto website and do a part search.

You could just remove the air cleaner and temporarily plug the hoses going to it or buy extra vacuum tubing and extend them so that they can remain attached when the air cleaner is removed. The hoses that attach to the air cleaner just attach to temp sensing vacuum valves so it is no big deal if you plug them.

You can view the 87 civic factory service manual (including the emission controls section) at redpepperracing.com


Thanks for the link, it's now booked marked!

GasSavers_Erik 08-23-2010 04:40 AM

Re: Installed new carb insulator= slightly higher idle?
 
That solenoid is the anti-dieseling solenoid. It cuts off the flow of gas through the idle circuit of the carb when the key is turned off.

If your car would not idle at all, but would run ok above 1700 rpms, I would suspect that solenoid- but I don't think that is your problem.

theholycow 08-23-2010 04:44 AM

Re: Installed new carb insulator= slightly higher idle?
 
Quote:

Originally Posted by Sport/Truck (Post 154168)
I've tried to insert a signature with vehicle, but can find the option?

If you're trying to put one of these in:
https://www.gassavers.org/gaslog/sig.php?id=1399
...then you'll need to add your car to the Garage by clicking on "Garage" at the top of the screen, and then click "Add Garage Entry". Next you'll need to enter some data in the gaslog. In your car's Garage page there will be a link you can paste into your sig.

If you just don't know how to put in a sig, go to the UserCP link on the same tab line as Garage. From there, click "Edit Signature".

Jay2TheRescue 08-23-2010 05:08 AM

Re: Installed new carb insulator= slightly higher idle?
 
I know what the problem is... Signatures are not available until you reach Junior Member. Once you have been a member for 30 days, and have a post count over 25 it will be available in your control panel. You also need to add your vehicles to your garage tab, and enter some fillups.

Once you have your vehicles in your garage, I may be able to manually add your vehicle's tag to a signature from the admin control panel.


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