gas/mileage issues in my '83 240 dl, B21A single carb engine

[sergitin32]

Hi every one, i was reading some other messages about gass mileage but they all newer cars than mine and fuel injection, with o2 lambda devices etc.
so I considered to create this as a new topic for the forum to share.

My story goes ike this: I filled the tank of my 1983 240 DL, canada assembled B21A single carburetor engine... the manual sais the tank carries 60 liters, so I just went all the way till i just got out of gass and the car stalled, one block form home in a back alley, thanks God. Mainly city driving i just got 300 km. I dunno where people gets that of Lady driven, cuz actually my wife puts some heavy throttle from stops, and i do all the contrary, i go slowly and smooth, enjoinng the feeling, i just upgraded my audio system and now i go even more smooth listening my tunes...

This would give me as result 5km per litters meaning a little more than
14 miles/ galon... sounds really crazy, so now i am sad one more time and worried.

The tires are inflated to the right preassure, the carb its been regulated several times by my self (not big deal) and hmmmm all the rest seams ok... Still havent read the real results for air care since i had a leak on the exhaust system, just fixed three days ago... so the previous readings were not acurate since the exhaust was escaping near the engine. No liking gas, the brake calipers and pads were changed in the front two weeks ago. No over heating... runs no so smooth but pretty well since its carbureted and i cant ask for more, but would like asking for more mileage before drains my economy... still love this car and love working things out for the best of our relation ejejejej.

Any sugestions or advices?
thanks alot guys, have a nice time, and late hapy new year!!!
sergitin.

[billofdurham]

a leak on the exhaust system

Depending how bad the leak was this could affect your fuel consumption.

Other than that you could have a sticking/worn needle or worn jets in the carb.

Bill.

[sergitin32]

Well, the times i tuned up and adjusted the carburator the needle was pretty even and straight, and of course super clean, how could it be sticking? now, one thing i have been wondered is where could i find some kind of chart to meassure my needle and know if its worn or not... same for the jet.

I also did something believeing the car was running lean, i made the flotant go higher into the gass chamber in the carburator... i believe that would make it go richer, but not that much, the deal is i had to run it with the choke out lamost , thats why i concluded it needed more fuel in the mix...

One more question, for how long should i wait for the car to heat when i start it , till it goes to the warm temp? or 3 minutes??? cuz most of the times we are in a hurry and just start it and go.. would that affect the mileage some how?

But then I realize also once the exhaust gasket is fixed i have to do the gas / mileage calculation one more time... and then from there take it to air care and maybe low the flotant a little bit to the right high...

ok these are just thoughts... the rest on the car is pretty nice, i am enjoying it very much...

thanks again Bill for clearing the way for me.
have fun and peace.
sergitin.

[billofdurham]

Sorry for the delay in replying but I have been waiting for my carb adviser to come back to work.

Checking the needle and the jet needs specialist equipment to be truly accurate. However, if the needle is moving easily then it should not be bent. The only other thing that may have happened to it is that someone has cleaned it with an abrasive. The jet tolerance is so fine that it is hard to measure without special kit.

The float should only be adjusted if the measurements are not as specified in the Haynes manual. It is not recommended that it be adjusted to try to compensate for other possible faults in the carb or its settings. If you are having to use the choke in normal running you need to tune the carb a little more.

for how long should i wait for the car to heat when i start it , till it goes to the warm temp? or 3 minutes??? cuz most of the times we are in a hurry and just start it and go.. would that affect the mileage some how?

Drive off as soon as it starts. Waiting for it to come to operational temperature, or 3 minutes, will affect your fuel consumption. You are burning it without going anywhere.

Bill.

[sergitin32]

Hi there ...
I've been busy and had not time to read this and some other docs i have about my car's carburetor... so i answer to Bill and just to keep the readers up to date and hopefully to get some more answers since I still have any clue of whats wrong.

For example the car is not leaking fuel from the lines, thats for sure... and its doing lets say about 6km/litter... but still when I go to air care, ALWAYS comes it is too lean, and i mean very very lean... I kinda sthought, of course with the exhaust leaking it is logical... so I fixed it, not leaking now, today went to aircare just thinking it would pass... nop, failed again... the leanest ever.
So came back to the pc try following the reasons Bill was giving me and joined all the paperwork about these (Zenith) Stromberg carburetor i have on the B21A.

anyway, i was thinking I should let you guys know here for sure, my carb is a Stromberg CD SE... in the upper cap of the carb I read this:
Solex - UK
175 CD 2 - SE

This means there are only 3 screws it has to graduate the mixture:
1-Throttle Stop Screw
2-Fast Idle Screw
3-Trimming Screw (in the bimetalic temp compensator valve or device)

the Jet doesn't have any lower adjustment which i think would be eassier to do... Using the coin... that lower cap is totally sealed.

Also the intake manifold has this screw just on top very close to the carburetor, i have been told it should be used for air adjustments to the intake...

So pretty much i have these 4 screws for carburetor adjustments; and the thing is I think I am going in circles here... and I dont want to play too much just in case i make it worse.

Any body please can make these adjustments clear for me some how? I will read this whole papers again to try having sorta epiphany or something.

Also how can I check the car doesnt have some intake leak, so its taking air from some where else except the carburetor mixture??

Thanx alot, and enjoy your day!
Sergitin.

[billofdurham]

You obviously have lots of literature on these carbs but here is a link to another one: http://www.mk1.connectfree.co.uk/nzcarb ... #Adjusting.

I have never seen a screw in the intake manifold that is used for adjusting the carb. The only adjustments I know are with the three screws on the carb.

To test for leaks on the intake manifold I have seen mechanics spray a very thin oil around the gasket whilst the engine is running. If there is a leak the oil is sucked into the system and comes out of the exhaust as dark smoke. It is not foolproof but I have seen it work.

On e further thing to check, if you have not already done so, is the constant temperature air device. If this is not working properly it will cause problems with the mixture.

Bill.

[sergitin32]

OK... here it goes. same old 1983 240 DL, B21A engine, Zenith Stromberg 175 CD carburetor:

(note here some photos are merged from two pics, so in the margen betwen some things go outta perspactive , but still the pic gives the idea petty well)

this is the hose coming from the warm start valve, i had to change it since the plug in tube broke cuz the hose was too short, i haven't still fix it, but will tomorrow for sure. What could this house be causing for my carb?



This are pic of different sights of the carburetor so you see how it looks like. In the frontal side you can see there is only one screw for adjustment, the fast iddle adjust.











In the two last pics of these 5 i pinpoint the screw i mentioned in the post before inside the red circle, the little screw its right beside the electrosomething in the top of the block with the green cable conected, this i've been told helps when you turn off the engine so it shuts off rapidly...
would anyone please let me know what is this screw for? i didnt move it form the original settings thou, but would be good to know if it can help in my mix probs.

next pics refear to mi temperature compensator.



in this pic you can see the trimming screw for the temp compensator (the bronxed one with tthe spring tight down); Now as far as i have read, this bimetal spring has to do with the mix depending on the temperatures, i think above 29 celciums the valve opens or close, lettin mor or less air into the ventury, changing a little the ratio... how should i trim it? at least anybody knows if counter or clock wise what this trimmin screw does??

So this is it as probs as I know with my carburetor...

Now some good news, i did got into moving the needle in the air valve, i made it a little higher, and i am open to play with this adjustment too so everything goes fine, since I just know now three possible adjstments as far as i can see here. Tha fast idle screw, the trimmin for the temp compensator, and the needle hight above the jet... i think i mentioned before the jet has not regulation from below.

and there is also that screw in the intake manifold i am not sure what it is good for...

I also discovered the bypass valve has some prob with the gasket and maybe the diafragm? so i am looking foward to buy a carb repair kit so i do a complete overall repair here... thats why i need to be sure what type of carb should i be looking for here, please, Bill your friend the carb specialist, could you show him the pics and ask him if he knows the exact name of this one... i was sue it was a ZS 175 CD2-SE but really now after all the info i am a little confused and not sure of this.

Also, whats the name of the part that engages with the carburetor intake and has the plugs for both hoses coming from the warm start valve? (the one its broken with the transparent hose attached in the pic) since i might look for some used one in some wreck yard, even if i glue mine, i need a good one.

In some of the pics you can read the info written on top of the carb. i think thats helpfull.

Thanks lots, and now for the end i have 2 more pics just to show my proud baby... sorry if this makes the super long extra large, but just to do it alright.





please forgive me for such a long email, but i needed it.
next one would be posting the works i have ben doing about this all and some other stuff.
thanx alot, apreciate
good day you all, god bless you all
Sergitin.

[billofdurham]

The saga continues:

The broken pipe from the hot start valve should only affect the engine starting when it has been operating at high temperatures. Fuel vapour builds up in the carb and is discharged when the throttle is closed, deflected into the air cleaner and drawn into the engine when it starts running. The part that is broken is known as a connecting plate - it connects the air filter to the carb.

The highlighted screw - Three of us have looked at this and can't remember ever seeing a screw there that would be used to adjust the mixture. It is too far from the carb. However, on some specs there was a nipple near that area which had a pipe coming from it - possibly some sort of vacuum but we have no experience of it. It has been suggested that you mark the position of the screw, take it out counting the number of turns it takes and see if you can find out if it is just a blanking screw.

the electrosomething

Very technical description. It is a solenoid valve and does just what you say.

The big bronzed screw with the spring under it is not the adjusting screw for the temperature compensating valve. It is the idle trimming screw. The adjusting screw for the temp compensator is inside the unit. Remove the two small screws to take off the plastic cover and you will see a cross headed screw inside. That is the adjuster. The only adjustment that may be needed is if the valve does not move easily in its housing loosen the adjuster screw and adjust its position. This should not be needed unless the valve has been taken apart and not aligned when it was rebuilt.

Looking at the pictures of the carb you do have a Zenith Stromberg 175 CD2-SE. That shape is distinctive as is the shape of the SU.

If you suspect the bypass valve has problems it would be better to fix that before trying to adjust the mixture as you would have to do it again.

One last point which is puzzling my friends. How do you manage to keep your hands so clean when you are working on your car, especially as you aren't wearing gloves?

The car looks good. I did not look that good when I was 25 years old!

Bill.

[billofdurham]

Well, they say two heads are better than one and we have now talked to another head who can remember seeing that screw next to the solenoid in the intake manifold.

It is for adjusting the idle speed but was usually fitted with the Zenith DVG 175 CDSU carb. It is possible that the manifold has been replaced or that this was what was fitted to Canadian models. By turning the screw in or out you should be able to bring the idle speed to between 850 and 950 rpm.

Bill.

[sergitin32]

I also have Bad news and bad news, which first, i guess the bad ones.

Anyway, I managed to take the carb off one more time and did my research on the phantom screw... as results of this are a few pic i'll just show you:
(some are photos merged in one so the borders are nos perfectly matching)














Ok, this is the screw out of the hole, its clear it is not a common screw plugging some old hole not been used in this car...

Now, the rest of the pics:











From the exploration I kinda noticed the hole comes from the groove in the manifold that conects with the holes though the gaskets and the face of the carb that connects to the intake manifold...

Also noticed thi hole goes to the electric-solenoid-thing and i dont discharge this solenoid is also conected to the hose coming from the vacum amplifier and entrying the manifold in the near by area of this device as seen in the pics (but can't asure this neither)... the real function??? my friend first told me that: (same as your contact told you, bill) it would do something in the idle/mix, but we moved it around and never changed anything in the idle, so we remained in doubt... and left it inits original position, 2 and 1/2 turns losing from tightened.

Now i am more sure it might be involve in the solenoid mechanism of shuting off the engine??? or some other function with some different carburetor?

Anyway Bill i did all this before i read this last post of yours... by the way i am no receiving all of these new posts on my mail, som i do, some i dont... this last one and some other before i didnt receive the email showing i have a new reply!!!!???

well... this being told, i anounce i just broke my metering needle yesterday and the carb is fully stall! i hate my self, but as always say, there is not way to find the true but facing defeat lots of times.. so i keep going.

Do you guys know of anywhere , phisical or any virtual internet location to buy a new metering needle for a stromberg 175 cd, the ones in the 1983 240dl? did several call yesterday and didnt find any, they are not been produced anymore so everybody is outta stuck and of coure i would like a new one... otherwise i would go as last resource to some wreck yard around.

I am looking foward to purchase a "rebuild carb" from a guy in Craigs List... but as ussual this makes me think lots before doing it; Could any of you tell me what should i look in a rebuild carb??? so i dont have issues?? the guy says it's from the same car year and model as mine, one year rebuild... and he also has another older for 30 bucks the rebuild one for 80 can... could you suggest anything i should be aware for this kinda transaction???

I think they are cheap, and always afraid when some one comes with cheap stuff offering them like good stuff.. 99% times is scam... so freaks me out cuz its always a dificult moment to deal with, more with my ESL...

well thanks for your patinece guys one more time, and for dealing with this bunchof info.

OH almost forget my secret to keep my hands so nice and clean without gloves: Do not touch the engine!!!!! i had not work on the car nor on the shop that day, was my day off, just was doing the post and decided "one pic worth thousand words", so I got the cam and went downstairs and shot some pics tippoiting with the fingers, didnt touch anything... so everything cool, other times you'll see the gloves or the bare hands really nasty sh..t covered.

have a nice dayguys and as ussual, ia am thankfull for or the help.
special thanks to Bill...lol.
Sergitin.