Honda D Series Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hello everyone! I have a 94 civic eg with d13b2 engine carburated. My urban fuel consumption with as economic driving as possible is about 12 litter per 100 km. I bought the car before a couple of months and from the begging it had this consumption. Is it Normal?
I have cleaned the carburator but nothing changed
Furthermore the engine runs very well and without idle problems so I believe that there is no vacuum leaks.
I have checked the emission but everything is normal

Where is the problem in your opinion ?
Thank you a lot for your answers
 

·
Registered
89 EF 4wd sedan
Joined
·
968 Posts
Hello everyone! I have a 94 civic eg with d13b2 engine carburated. My urban fuel consumption with as economic driving as possible is about 12 litter per 100 km. I bought the car before a couple of months and from the begging it had this consumption. Is it Normal?
I have cleaned the carburator but nothing changed
Furthermore the engine runs very well and without idle problems so I believe that there is no vacuum leaks.
I have checked the emission but everything is normal

Where is the problem in your opinion ?
Thank you a lot for your answers
First thing i'd check is your method of calculating your fuel consumption. You're resetting your odometer at each fillup and dividing the liters used (as shown by the fuel pump) by the amount of kms driven?

You should be seeing between mid 7's and mid 8's in strictly urban driving.

What's the service history like on the car? Plugs, dizzy points, filters, oils.. Any of those done?

Any fuel leaks? Smoke?
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
Thank you for your reply

I calculate my fuel consumption with way you describe
I have changed plugs and air filter before 2 months.
I haven't changed oil and oil filter
There are no fuel leakes
The only thing that I noticed is that in the rear bumber near muffler there is some black dirt
 

·
Registered
93 Civic HB SI
Joined
·
1,701 Posts
Single carb? dual carb? Downdraft, sidedraft? OEM or aftermarket? Vacuum advance in the distributor working normally? Does it feel like it has good power under heavy load/acceleration?
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
Single carb? dual carb? Downdraft, sidedraft? OEM or aftermarket? Vacuum advance in the distributor working normally? Does it feel like it has good power under heavy load/acceleration?
Thank you for youw answer

I have the OEM single carb with two stages as you can see in the depicted pictures.

How can I check the vacuum advance in the distributor?

I think that it has normal power under heavy load but i am not the suitable person to answer that question because i haven't driven another d13b2.
The car seem to run well in the whole range of the RPM.
 

Attachments

·
Registered
93 Civic HB SI
Joined
·
1,701 Posts
I have checked the fuel emissions and they were normal
You say you checked "emissions", with what may I ask?

Your engine should definitely be capable of the 7 to 8L/100KM or approx 30MPG that EFB055 suggested.

Like transzex said, make sure intake and exhaust are restriction free. Make sure base timing is right (get the correct service manual for your vehicle year/make/model to check this). Make sure the choke flap opens up all the way once the engine warms up. If it stays partially closed, it will use excessive fuel.

If you say there is black soot on the bumper, that is a sign of running rich. Have a friend watch the exhaust pipe while you snap the throttle open. The exhaust should be soot free when that happens. If there is any indication of black soot under basic unloaded acceleration, it is running too rich.


To check the vacuum advance in the distributor, you will need:

a) a handheld vacuum pump
b) a vacuum gauge
c) the proper vacuum diagrams for your vehicle.


1. You should have two ports on the distributor vacuum advance diaphragm, the top one is for throttle tip-in advance.

2. Pull the distributor cap and rotor off so you can see the guts of the distributor.

3. Use the handheld vacuum pump to pull a slight amount of vacuum against the diaphragm at the top port to see if it can pull the timing advance control rod.

Refer to the attached picture. If the vacuum pump successfully moves the pickup ears in a counterclockwise rotation, and it can hold position using the vacuum pump without slowly leaking down, this indicates the vacuum advance mechanism works correctly and is not leaking any air/vacuum. (A good thing)


4. If that all works, put a vacuum gauge on the hose that was connected to the distributor diaphragm top port. This hose should be connected to the throttle body at a "signal" vacuum port, not a "constant" vacuum port. There is a difference.

5. You can tell you are connected to signal vacuum by watching the vacuum gauge. Start the engine. If the vacuum gauge doesn't move off of zero by much or at all, your off to a good start. Now, blip the throttle. The gauge should pull down into the vacuum range, ONLY during the time you pressed the throttle, then return back to zero when your foot is off the throttle. It is only during part throttle application like this that vacuum advance works.


Under open throttle conditions, there will be little to no vacuum in the intake manifold to pull on the advance diaphragm to move the rod. The lower portion of the distributor contains sprung weights with a mechanism that will automatically advance the timing as RPM rises. If this mechanism is rusty, I have seen the weights not able to fling out and advance the timing.

Hopefully this gives you some guidance.
 

Attachments

1 - 10 of 10 Posts
Top