HELP!!! New carb and its still hard to start, stumbles...grrrrrr

[Uncle Don]

ive had an issue since ive owned my car (318 poly motor with a factory 2bbl), that its hard to start, you have to pump and pump and pump and pump and then it "might" start...once it was running it was o.k....would stumble at quick throttle, but soso out on the open road. this was even after a kit had been put in the old stromberg... most things have been replaced recently to try and approve...its had a fuel pump, points, plugs put on it....

so i broke down and bought a remanufactured carb from carb specialist out of georgia...stock replacement 2bbl stromberg. it ran fine right out of the box for a DAY...1 DAY. so this morning (after driving it last night around town) it wouldnt start again....crank and crank and pump and pump and pump...after a few words of encouragment it finally started...ran ok, but stumbled and acted sluggish like my old carb. nice. money well spent??? why did it run so good yesterday....so what are my options? where do i start?

1. could it be choke? choke bad?
2. do i need to put new electronic distributor and coil on it?
3. vacuum? on my old carb i did not have my vacuum line from carb to distributor hooked up, for some strange reason it ran better without it hooked up. new carb so do i hook this back up maybe???
4. big block and nice 4bbl and quit fooling with this poly motor?....:icon_axe:

 

[65-440]

are you positive your problem is carb related and not ignition ??

 

[GTXKen]

I would pick #4 but thats personal preference and a bit spendy.

I would defiantly be looking for an ignition problem, I hate to just throw parts at a problem though. I'd check out the dist shaft play, check the advance mechanism and the point settings....ok...thinking out load here...no I wouldn't...I'd ditch the points dist for a mopar electronic unit. Even if it didn't fix the problem you would be done with the pia points!

 

[Uncle Don]

im checking into it now, but im thinking that my gas is dissapearing out of my bowl in the carb...i can pump and pump and pump and it doesn't flood it, theres not a strong gas smell or anything....very strange. it could be ignition....and yeah i hate to just throw parts at it to, especially when im going to big block it this coming winter...less i spend on this poly the better i feel.

 

[Patrick]

This sounds more like ignition than fuel. I think the reason it runs rough when it does start is because its flooded. 1: Today's gas needs a hotter spark than the leaded fuel your system was designed for. 2: Today's gas is a high evaporation fuel thats hard to light. Like the one guy said if upgrade don't cure it your money ahead. With evaporation in mind carb cars need a 7psi electric fuel pump near the tank to prime the carb. When you shut a carb car off engine heat evaporates the fuel thats in the carb causing hard starting. Not to mention the wear caused from dry cylinder walls. One or both of these things will cure the problem.

 

[65-440]

you can buy a pretty decent electric pump for a fairly good price, then you could fill the bowls with the flip of a switch !!

 

[65-440]

summit sells pump/regualtor combos for a good price ...

 

[YY1]

Has it ever had a timing chain?

I've seen many loose timing chains mis-diagnosed as bad carbs.

Can cause stumbling and inconsistant timing that seems like advance is wrong but never quite adjusts out.

Vacuum line indifference plays into this scenario as well.


At 58K it's about time anyway.


..or you could just rid yourself of your problems by giving me that beautiful car.

Did the heater issue ever get resolved?

Electronic ignition is a good idea as well as relatively cheap and easy.

 

[RH62]

could it be a choke adjustment. after you crack for a bit with a couple pumps check to see if the choke blade is closed.
I had similar problem with my plymouth i pulled the aircleaner opened the choke blade and it fired on the very next crank. I havent had time to mess trouble shoot it any farther yet but i think a choke adjustment might be outa whack.

 

[Uncle Don]

Has it ever had a timing chain?

I've seen many loose timing chains mis-diagnosed as bad carbs.

Can cause stumbling and inconsistant timing that seems like advance is wrong but never quite adjusts out.

Vacuum line indifference plays into this scenario as well.


At 58K it's about time anyway.


..or you could just rid yourself of your problems by giving me that beautiful car.

Did the heater issue ever get resolved?

Electronic ignition is a good idea as well as relatively cheap and easy.

NO the heater issue has not went away, its just really nice this week here about mid to upper 60's so i got it out and dusted it off some...im replacing the heater core in the next couple of weeks.

i did find something out last night and may be my problem...after about 2 1/2 hours of my car sitting, i went down and stared at it some more and i noticed that all the fuel was gone out of my inline clear fuel filter...it was full of fuel just a couple of hours earlier. shouldn't it still be full of fuel??? which leads to i have been told to replace all my original rubber lines on the car in the fuel system...that some or all maybe dry rotted and not holding pressure to where fuel is up at the carb??? sounds logical...

whats you guys think?

and i may have two problems on it, i noticed that when its warmed up and choke is in operating range(whatever that is) the flapper door is not totally open(straight up and down), its more like 3/4's of the way open, i can manually grab the choke arm and open the carb flapper all way open..??? so when its warm and been running awhile shouldn't it be fully 100% open?

 

[wlo48]

Not assuming anything, you replaced points and plugs, fuel pump, and now carb.
Did you set timing after setting the points? You said the vacumn line was disconnected so it would not affect the timing while setting it. Did you verify that the mechanical timing advance was working by revving the motor and watching the timing mark advance? Hooking the vacumn advance up while checking the timing would verify if there were a problem here.
I assume the distributor vacumn port is capped. Needs to be if it is not.
Did you do a vacumn test? the highest expense here is the cost of the gauge, which is actually low when you check the price.
Electronic ignition is the way to go but if you are going big block later and want to keep the 318 maintenance cost down the points will "work".
Replacing the rubber gas lines is an excellent thought. I would start with the short piece at the tank. It is very often overlooked and can cause the most trouble. Start there with the replacement job.
You have a clear fuel filter. Is it between the fuel pump and carb or between the fuel pump and gas tank? Mechanical fuel pumps push better than pull, by placing a filter between tank and pump the pump has to work harder and sometimes will "starve" the motor for fuel. Make sure the filter is between pump and carb.
At the time you installed the carb, did you adjust the choke? If not, adjust the choke with the motor "stone dead cold". Adjust the choke so the blade is ALMOST closed completely. When the motor gets hot it should be fully open. Don't try to adjust the choke when the motor is hot, the adjustment will be wrong.
The electric fuel pump and regulator is an excellent idea but I like to do the low cost items first and work my way to the "have to have it" part last. You said that you replaced the fuel pump. Was it a new one or reman'ed? There is a check valve in the mech pumps to keep the fuel from syphoning back to the tank after shut down. With the filter being empty after sitting for awhile the fuel pump valve maybe bad even though it is a new pump. My vacumn gauge also doubles as a fuel pressure gauge. If you have one, hook it up between carb and pump, take a reading while running, shut down and take readings periodically and watch for a pressue drop. Naturally it will drop but should not drop quickly which is a sign that valve is bad.
Good Luck,

 

[Uncle Don]

fuel filter is between fuel pump and carb...about 8" from carb actually.
thats a good point on the pump, im not sure if i put "new" or reman"...cant remember.
yes i set timing after points put in, put a light on it etc...
i have not adjusted the choke...i have no idea how??? please explain how to adjust it and ill have at it. thanks for all your help guys...someday ill be able to return the favor.

 

[Uncle Don]

when car is warmed up to operating temperature should the flap on carb be straight up and down or about 3/4's of the way open??? which is where mine is when warm, it won't go all the way open..is they way its suppose to be?

 

[wlo48]

I haven't seen mention of the heat riser valve located in the passenger side exhaust manifold. If this sticks, it will normally stick closed, force the exhaust through the crossover passage under the carb and out the driver side exhaust. When this happens the carb gets abnormally hot and will sometimes "boil" the gas out when the motor is shut down. With the motor cold, reach down to the heat riser valve and see if it moves freely by rotating it. If it does not move freely it may be stuck. It needs to be free. Spray your favorite lube or cleaner on it, work it until it is free.
The choke butterfly should be all the way open when at operating temperature. Right at this time I can't remember how to adjust it. (I am been undergoing chemo and it has destroyed some of my memory). Sorry about that.

 

[HEMI-ITIS]

Did you verify the fuel bowl actually filling with fuel!!When you pump the gas,does gas squirt strong into the carb??Did you check fuel pressure AT THE CARB??

 

[Uncle Don]

never thought of that, i will check that, good idea....see i love this board!

 

[Uncle Don]

Did you verify the fuel bowl actually filling with fuel!!When you pump the gas,does gas squirt strong into the carb??Did you check fuel pressure AT THE CARB??

yep, i let it set a couple of days and still had gas in the carb, some gas in the fuel filter, so that seems to be working now.....when i move the throttle plenty of gas is coming out when cold after a day or two...so it may be my choke not operating correctly backto that idea gain..

right now i have my heater bypass valve out of car, working on getting all that lined out so my heat and air will work, then back to the carb to see whats up.

 

[mrkinger]

If there is no fuel in the bowl and it isnt flooding by pumping the heck out of it ,i would think fuel pump