Gas mileage/Hot starting problem

[hippie_elmo]

I have a 1972 250. I would like to know the milage of the 250 in the city. I have gone 60 miles on a half a tank of gas. Seems allot to me. Is this normal? What can I do to increase the gas millage?


It takes allot of cranking to get my 250 started when the engine is hot. How could I fix this problem?

[Mark DiSilvestro]

Sounds like your 250 is running rich.
These cars aren't noted for great gas mileage. With adjustment of carb and timing, mine gets about 14 MPG city, 20 MPG highway.

Happy Motoring, Mark

[gmask]

I don't have my manual handy but your carbs probably need a minimal rebuild. I'm guessing that the fuel valves are either stuck or sticky or are damaged. The 72 models have this little ball int he fuel valve that falls off and therefore you are probably flooding when you are starting hot and because the fuel keeps running then you are burning mroe than it should. I was having a hard time starting until I replaced mine but now I can turn the key without even touching the gas and it starts.

parts.mbz.org has the rebuild kits ze-28k for $35 per carb.

Doing this rebuild is easy and does not require that the carbs even be taken off the car. You will have to remove the top two sections but the rest of the carb can stay mounted.

Anyway if you into it I can give more info based on my recent experience rebuilding.

You should make this repair a priority. Not all that unburned gas is going out the tailpipe. You may be diluting the engine oil with gasoline.

[hippie_elmo]

I was thinking that the carbs might need a rebuild. Could this also effect cold starting? Could this also effect the temp. of the engine? My car runs very hot. What other parts are in the carb. rebuild kit that you are talking about?

[gmask]

Originally posted by hippie_elmo
I was thinking that the carbs might need a rebuild. Could this also effect cold starting? Could this also effect the temp. of the engine? My car runs very hot. What other parts are in the carb. rebuild kit that you are talking about?

I'm not sure how it would effect the engine temp. Is this the car that does not have an electric fan on the radiator? What temp is it running at?

Since it seems that the fuel needle valve is not working then you are probably flooding the engine when starting wether hot or cold. The 72's have these little balls in them that fall out chances are that only one has fallen out but you might as wel do each carb. I think you have to get the ze-28k in order to replace the fuel needle valves. Each kit comes with several variances on the gaskets for the carb so you won't use everything in the kit. There are a few other gaskets that are convienent to replace.

Bascially you unscrew all the bolts from the top including the one in the center where the air cleaner screws. If you can't pull the top off then you gently pry with a small screwdriver between the two barrels be sure not to mar the surfaces.

From here there are two screws holding the fuel bowl down.

Once you have removed it you can replace the fuel needle valve.

Before reassembling clean all the old gasket off using a plastic or wood scraper. You may wish to clean the carb with carb cleaner before starting and then scrub each part and spary it with more cleaner. Be sure to do this outside and preferably with a light duty face mask. If you can you should spray the parts and then leave the area until the air clears.

Do each carb one at a time and put the rebuilt carb back on the manifold if you renew the exhaust manifold gaskets which is also a good idea.

Check how the car runs.

Then do the next one.

Once you have both rebuilt then make sure that the automatic choke covers are set 5mm past the rich mark. 5mm is basically just where the notch on the cover will go out of view as you turn the cover clockwise.

Then adjust the idle speed .. if you have problems gettin gthem to sync I have found that the adjustments screws get out of whack and need to taken off and adjusted so that both are at their maximum and then you can adjustment them down and you will have a better range of adjustment.

[hippie_elmo]

This is the car without the electric fan. The car runs from 175 to 200. Could the hot starting problem be becuase the carbs are warped also?

This is problem I had with my famous Solex 280.

[gmask]

Originally posted by hippie_elmo
This is the car without the electric fan. The car runs from 175 to 200. Could the hot starting problem be becuase the carbs are warped also?

This is problem I had with my famous Solex 280.

I think those ar efairly normal temperatures to be running at. If you have the electirc fan it would not kick in until the temp hit 212 anyway. Frankly I don't know why they made these cars without an electric fan.. I guess because that car did not have AC standard or you are in a mild climate.

According to the Zenith manual a hot starting problem is due to either the venting valve which was removed for 72 models or the float level. Since the 72 models have the fuel needle valves with the little ball int he tip that tend to fall I would bet that one if not both have fallen out and that when you proabbly flooding the engine when you hot start.

You should beable to test this by doing a hot start .. do not press the gas pedal and then take the air filter off and if the carbs reek or gas then you are flooding it.

This would also account for the poor gas mileage as there is nothing to stop the flow of fuel into the carbs if the fuel needle valve ball has fallen out.

You could easily do this work yourself or call around and see what the prices are for local rebuilders.. I found a guy here that said he would do the pair for $90 but I have no idea if that would be anything more than replacing the gaskets. Some places quoted as much as $400! Doing this repair is actually pretty easy and does not require any special tools and would probably take you several hours to do the first one and then even fewer for the second.

[hippie_elmo]

Thanks for the information. I'm going to look more into it. Right now, it has been raining here for the past two days. Yesterday I went to start the car and It won't start. I checked the air filter, oil etc. everything is good.

I just went outside (not raining for the past couple of hours) still won't start. Not sure what the problem is.

[gmask]

Originally posted by hippie_elmo
I just went outside (not raining for the past couple of hours) still won't start. Not sure what the problem is.

I'm in LA so the rain has been keeping me from working as well. Do the carbs reek of gasoline?

[hippie_elmo]

I got it started! I didn't smell any gas. It seems that water is getting in becuase the hood isn't flush with the body. So I need to adjust the hood closing stops. And the water got around the battery and must of done something. I sparyed allot of carb. cleaner in both of carbs. And it seems to run allot better then before!

[gmask]

Originally posted by hippie_elmo
I got it started! I didn't smell any gas. It seems that water is getting in becuase the hood isn't flush with the body. So I need to adjust the hood closing stops. And the water got around the battery and must of done something. I sparyed allot of carb. cleaner in both of carbs. And it seems to run allot better then before!

I used to get that alot too when it rains your battery contacts may be loose or worn out.

[hippie_elmo]

I will have to check the battery cables. I did a hot start, It started right up!! I had no problem, the carb. cleaner must have done soemthing..

[gmask]

Originally posted by hippie_elmo
I will have to check the battery cables. I did a hot start, It started right up!! I had no problem, the carb. cleaner must have done soemthing..

I suppose your flaps where stuck??? It is amazing how much can be wrong with these carbs and they will still work. The next problem you'll want to tackle is the fuel usage. Sounds like you are currently getting about 10 miles per gallon. I'm failry certain that the fuel needle valves are not functioning properly but the only way to know for sure is to open the carbs. I guess if you took the carbs off you would here the little ball rolling around loose inside it. Check your oil cap.. does it smell like gas?

[hippie_elmo]

I did a warm start yesterday. Turned right over with the first turn of the key.

I checked the oil cap and I didn't smell any gas.

It is funny that carbs. can be really massed up and the car will still run.