engine and drivetrain 68 1600-2 Breaking Up/ Bucking

[PoorBoysRacing]

Hi guys, been trying to figure this out on my own for a dew weeks now.

 

My car is a 68 1600-2 with a webber 32/36.

 

When you start the car it will idle beautifully. and rev without issue.

 

When you go to set off it will start "missing" or "breaking up" while accelerating. Sometimes quite badly, sometimes barely at all. It seems to get worse the more throttle you give it.

 

Other times it will run just fine.

 

 

I have put in new points, rotor, cap, plugs, wires, new fuel filter.

 

re adjusted the carb, and tried re adjusting the timing to see it it helped.

 

All in all no real difference.

 

Just looking for what to check next, or some new ideas as to what could be going on.

 

THANKS!

Joe

[FunkyLaneO]

Fuel starvation? check the filter screen on the fuel sender. make sure fuel pump is working, no air leaks in the fuel line leading up to the fuel pump (vacuum side, it will suck air if you have a pinhole).

 

just a guess, also double check your timing.

[bill.in.mt]

vacuum leak?

[PoorBoysRacing]

I think we've got a winner on starvation. Looked at my 1 week old fuel filter...full of sand looking stiff.
pulled the sending unit. No screen in sight. Tank looks full of crap too.





now, how to clean the tank,

drain, flush with water, let air dry?

never had to do this before.

thanks!

Fuel starvation? check the filter screen on the fuel sender. make sure fuel pump is working, no air leaks in the fuel line leading up to the fuel pump (vacuum side, it will suck air if you have a pinhole).

just a guess, also double check your timing.

Edited July 15, 2013 by PoorBoysRacing

[FunkyLaneO]

The only way I know is to drain and remove the tank and clean it with some solvent (such as gasoline) if it is just free floating crud you may be able to let it settle and then carefully siphon it out but at best you will only get a portion of it and will still replace a few fuel filters. 

 

the best way (also the hardest)

1. drain the tank,

2. remove tank from car,

3. introduce some clean gasoline (just a little),

4. swish around,

5. pour out

6. repeat steps 3-5 a couple more times

7. look inside and see if it is clean, if it is, reinstall tank, if not, keep going or devise a plan B.

 

I would see if you can get a screen for your sender, maybe somebody here has one for sale, post in the WTB section.

 

Gas is expensive, if there is no water in the gas you are taking out maybe you could filter it through a coffee filter and salvage some of it, just an idea.

 

also BE SUPER CAREFUL! it isn't the gas that is explosive, it is the vapor and the tank is most dangerous when it is freshly emptied.

[PoorBoysRacing]

ok, cleaned tank with gas, got alot out.

 

Put in new filters (one before pump, and one before  carb)

 

Gassed her up and she was running great for all of 2 blocks.

 

Noticed that my fuel pressure must have dropped since my pre carb filter want full anymore. Was just a trickle.

 

Fuel pump started knocking, so i went and got a new Mr Gasket 42s in line pump.

 

New one is nice and quiet now but the car still has barely any pressure.

 

 

 

Tomorrows plans include double checking all the lines to ensure no kinks, By passing the pre pump filter to make sure that is not restricting it, if issue still presents im going to put in all new lines.

 

At least i finally feel like im tracking down its issue.

 

 

 

Also as a side note, Was reading here :http://www.racetep.com/webfuelspark.html about not hooking your advance up to the intake, gonna double check tomorrow but im pretty sure thats where mine runs too. DOH!

 

Gotta Love previous owners lol

[Slavs]

It could be running lean. From experience with a 1600cc with a 32/36 I can attest that out of the box this carb only worked at idle on my car. As soon as the secondary opened up, it just stumbled. So what I did was to increase the size  primary and secondary fuel jets until the stumbling stopped. To my surprise, the stumbling stopped only once I brought the primary fuel to about 150 from the 135 that the carb came with. I also sized down the air jet on the primary to about 160 or 150 ( I can't exactly remember, but it was almost , if not the same as the main fuel. I did a similar thing to the secondary and increased the fuel jet to 160 or 165. The main air was about 170 or 175. I forgot what I used for the idle. But the stock idle jet didn't work. Creighton's jetting formula for the 2 liter is similar to mine, but mine is richer. I removed the 32/36 and replaced it with the stock single barrel PDSI38-40 because the mpg is much better with the smaller carb. The performance gain with the 32/36 is not noticeable unless you're running at full throttle. 

 

SLavs