4k Sputtering When Secondaries Kick In?

[Evan G]

gday fellas,

 

I'm a little confused...

 

i changed my fuel pump over yesterday. notice some spluttering when cold but fine when hot.

 

i bought a new ballast resistor out of a different type of car for it. didnt look like the old one so i decided to measure the resistance of the new one vs. old

 

new. 1 ohm

old. 2.5ohms

 

so i slapped the old one on.

 

took it for a drive and ive noticed when the secondaires kick in splutters badly.

 

even if you slowly apply the throttle primary to secondary just dies/jerks/pops

 

blocked curcit?

 

cheers for any advice

Edited July 18, 2010 by Evan G

[altezzaclub]

Sounds like it leans out, so either secondary jet blocked or something wrong in there.

 

Unless the pump is not delivering enough fuel to keep the bowl full to the right level. That might be worth checking.

 

How about a bit of shit getting passed up the line when you changed pumps?

[Evan G]

Sounds like it leans out, so either secondary jet blocked or something wrong in there.

 

Unless the pump is not delivering enough fuel to keep the bowl full to the right level. That might be worth checking.

 

How about a bit of shit getting passed up the line when you changed pumps?

 

i was thinking along those lines,

 

to get to the secondary jet, remove the top part of the carby and its on the bottom somewhere?

 

ill try giving it a gental tap tap tap-a-roo

[Evan G]

ok on the way to work sputtering with secondaires.

 

on the way home was fine? didnt feel it at all in 1st 2nd 3rd but felt it 4th?

 

took my air cleaner off, secondaries were getting fuel

 

i thinking something like fuel bowl level? or ignition under load?

 

but how can the secondaires be starving and the primary don't?

[altezzaclub]

Well, by the time you hit secondaries the motor is sucking a lot more fuel out of the bowl, and the maximum would be in 4th. If you're going to empty the fuel bowl it would be having wound it up through the gears to 4th.

 

Unlikely to be pump if it disappeared then came back, if it was a pump or flow problem it should be constant.

 

So it something that moves so it cuts the fuel off then allows it some other time. My ol' man had it in his Vauxhall Cresta- a leaf in the fuel tank that killed it stone dead once every month or two. Stop the car and it floated off the outlet and away you went again.

 

Any shit in the fuel bowl or jets?? Something in the fuel line just above the float valve?

[Evan G]

Well, by the time you hit secondaries the motor is sucking a lot more fuel out of the bowl, and the maximum would be in 4th. If you're going to empty the fuel bowl it would be having wound it up through the gears to 4th.

 

Unlikely to be pump if it disappeared then came back, if it was a pump or flow problem it should be constant.

 

So it something that moves so it cuts the fuel off then allows it some other time. My ol' man had it in his Vauxhall Cresta- a leaf in the fuel tank that killed it stone dead once every month or two. Stop the car and it floated off the outlet and away you went again.

 

Any shit in the fuel bowl or jets?? Something in the fuel line just above the float valve?

 

well i did get 92% on my brake test then it was fine LOL!

 

ill pull the top of the carby off and make sure theres no threebond bits hanging around.

 

the larger the clearance between the fuel bowl and the thing that valve that lets the fuel in, will make it fill up quicker or slower?

Edited July 19, 2010 by Evan G

[Bamboo]

That sounds like ignition. I reckon it might be something simple like a faulty plug or lead having a "break down" underload. As you said it's getting fuel there.

 

The simple things first before you start ripping it apart. Remember the carb was working aok on the last engine. I've seen new plugs fail before!!

[Evan G]

That sounds like ignition. I reckon it might be something simple like a faulty plug or lead having a "break down" underload. As you said it's getting fuel there.

 

The simple things first before you start ripping it apart. Remember the carb was working aok on the last engine. I've seen new plugs fail before!!

 

ive reused my old plugs/leads out of my other 55 (witch also was working fine).

 

- I'm revving my new motor alot more than my old one, so fuel bowl draining might be a possibitly

- dwell is 42 degrees

- timing is on 12 degrees

- using a old ballast resistor

 

poo randomly blocking the jet could also be a possibitly.

 

ill take the top of the carby tonight a report back

[ke70dave]

attack it with carby cleaner too, nothing like a good does of carby cleaner.

[Bamboo]

cross the leads and back fire start the engine. If there is any shit, it will blow it up through the carby.

 

Easier then removing it

[Andy43]

Is it mech or vac secondarys ?

If Mech Sounds like the flapper may be jammed open, or the jet blocked.

As both jets are in the bottom of the float chamber don't think it is float level.

The secondary jet is the one that screws in vertical and should be a 144 or 141 or 126 for 3k not sure about 4k could be 144 or 156 ??

Note also pri jet is yellow in colour and the sec jet is silver.

You should be able to rev the engine with the air cleaner off and slowly open the secondry butterfy early, Hard to explane open pri with thumb and sec with index finger and fuel should come out of both verturi boosters.

 

Don't discount the fuel filter could be that as well.

 

Cheers

Andy

Edited July 21, 2010 by Andy43

[Evan G]

Is it mech or vac secondarys ?

If Mech Sounds like the flapper may be jammed open, or the jet blocked.

As both jets are in the bottom of the float chamber don't think it is float level.

The secondary jet is the one that screws in vertical and should be a 144 or 141 or 126 for 3k not sure about 4k could be 144 or 156 ??

Note also pri jet is yellow in colour and the sec jet is silver.

You should be able to rev the engine with the air cleaner off and slowly open the secondry butterfy early, Hard to explane open pri with thumb and sec with index finger and fuel should come out of both verturi boosters.

 

Don't discount the fuel filter could be that as well.

 

Cheers

Andy

 

its mechanical secondarys,

 

i opened the sec by hand and there was fuel coming out out the venturies.

 

fuel filter is new..

 

i locked up the brakes f@$king hard when doing my brake test, drove it back to work, left it for about 30mins, took off home.

then it was fine through 1st 2nd 3rd and poo in 4th

 

i couldnt see smoke coming out the exhaust either? in the light & dark. i slowed down when there was a car behind me. booted it, sputterering and couldnt see anything in my rearview?

 

if it was ignition related wouldnt i see smoke?

[altezzaclub]

there was fuel coming out out the venturies

 

So if you pump it quickly a couple of times when it misses, does it cover the miss?

 

The pump jets are obviously working in both throats, but the 2nd jet might still be blocked.

[Evan G]

So if you pump it quickly a couple of times when it misses, does it cover the miss?

 

The pump jets are obviously working in both throats, but the 2nd jet might still be blocked.

 

 

nope does jack shiet, hold your foot steady, does nothing.

 

gotta release the gas till it goes back into primaries to get moving

[altezzaclub]

ooohh.. tricky!

 

So you know there's raw petrol being pumped in there and it still can't go.