Ae82 Carby Problems, Carby Tuning help Options

[clubby2084]

Hi Guys,
Just reading the topic below and the problems Skippy1331 is having, and I'm having a similar problem with my AE82.

I have done all the things recommended in his thread (fuel filter, tank, carby rebuild, vacuum lines etc etc) but still have the same issues. Huge flat spots and surging. I get a flat spot turning left and sometimes it snuffs out, and big flat spot every time the secondaries open when I put the foot down.
I have had the carby reconditioned 3 times in 3 years (on recommendation from mechanics) and I've had no luck, the problems persist.

On the subject of tuning the carb. The last time I had the carby reconditioned I dropped the car off at my mechanics, he sent the carb to a "specialist".
This specialist rebuilt the carb and tuned it on an engine he has in his workshop. The engine in the workshop was a Holden 202 Red with an adapter to make my carb fit.

Now, to me that sounds like the carb is being tuned for a 202 and not a little 4A. I would have thought a 3.3 liter 6 would have very different fuel/air requirements to a 1.6.
I also think the jets may be the wrong size as well, and this is why I get terrible flat spots.
When I brought these issues up with my mechanic he assured me this wasn't the case.
I have since taken the car back a number of times with carby problems (warranty) and my mechanic has told me to take it somewhere else because all his mechanics are young and don't understand or work on carby's !!!.

Any ideas or suggestions ?.

[Sloth]

When I had carby issues with my twin SUs it turned out that we were using the wrong sized needles (someone else on here had a similar problem not too long ago). I know nothing about this sort of stuff, but if you post up what sized carby you are running (if it's not the stock one from that car/engine) somebody smarter than me might be able to tell you what parts you need.

[chappo12]

sounds like you need a new mechanic.

take the car with the carby on the engine to a shop and get them to tune it.

[Trev]

You ever thought the fuel pump isn't working 100% because that it what I am believing is your problem.

[clubby2084]

Thanks chappo12, while I tend to agree I need another mechanic, good ones don't seem to be in abundance.
I've had 3 mechanics who recommended rebuilds and 3 fails (only the last guy had the carb off and sent to a specialist, the rest did it on car).
You see my problem, take it to ANOTHER mechanic and I guarantee his first response is, "it needs a rebuild". Back to square one.
And after spending well over $1300 on a standard carby I'm kinda reluctant to spend any more on it.

Thanks Trev - I did think about it once or twice a while back, but thought, naaah, couldn't be. My previous experiences with mechanical fuel pumps is they go kaput without warning.
Wouldn't think a flogged out fuel pump would last 40thousand kays (this is how long it's been going on). But OK, can't hurt. I'll give that a go and let you know.

[Trev]

Thanks chappo12, while I tend to agree I need another mechanic, good ones don't seem to be in abundance.
I've had 3 mechanics who recommended rebuilds and 3 fails (only the last guy had the carb off and sent to a specialist, the rest did it on car).
You see my problem, take it to ANOTHER mechanic and I guarantee his first response is, "it needs a rebuild". Back to square one.
And after spending well over $1300 on a standard carby I'm kinda reluctant to spend any more on it.

Thanks Trev - I did think about it once or twice a while back, but thought, naaah, couldn't be. My previous experiences with mechanical fuel pumps is they go kaput without warning.
Wouldn't think a flogged out fuel pump would last 40thousand kays (this is how long it's been going on). But OK, can't hurt. I'll give that a go and let you know.

No mine was doing the same thing 6 years ago after I put a new pump on, I took the pump off and realised the diaphragm was opening later then the one that was one it (which was removed due to a worn diaphragm), I took it back to autobarn and told them it was farked and an argument proceeded that I was wrong so after 10 mins they jumped on the phone to to the manufacturer (fuel miser I think it was) and there response was yeah mate we had a batch of bad diaphragms so I ordered a different one and it was good.

My main problem was if I started the car up and let it idle it would stall as soon as the carby was empty of fuel and I used to have to start it with carby clean.

EDIT: I have the carby off my car here if you wanted me to send up so you can try it.

This post has been edited by Trev: Jul 7 2010, 04:47 PM

[Suziefox73]

Hey, the tuning of a carb on any motor other than the one it's going to be running on is dodgy, every motor is different! For the price of three trips to your ex mechanic you could of bought a secondhand 32/36 DGAV or the like rebuild kit, adaptor plate and air filter to suit the trouble prone factory carb! Jetting for a 32/36 for a 4AC-4AFC should read as so, Primary fuel jet 125-130, Primary air correction jet 160-170 secondary fuel jet 120-125 secondary air correction jet 175-185 and 45 idle jets for both primary and secondaries, stock everything else! Or leave it stock and change the secondary air correction jet to say a 190 for a quick fix but it'll run a bit rich high up! In Darwin pull out the choke plates and block off the water choke vac hole! Give a man a fish, he'll eat for a day! Teach him how to fish he'll eat forever!

[RainWarriorDregs]

Hey, the tuning of a carb on any motor other than the one it's going to be running on is dodgy, every motor is different! For the price of three trips to your ex mechanic you could of bought a secondhand 32/36 DGAV or the like rebuild kit, adaptor plate and air filter to suit the trouble prone factory carb! Jetting for a 32/36 for a 4AC-4AFC should read as so, Primary fuel jet 125-130, Primary air correction jet 160-170 secondary fuel jet 120-125 secondary air correction jet 175-185 and 45 idle jets for both primary and secondaries, stock everything else! Or leave it stock and change the secondary air correction jet to say a 190 for a quick fix but it'll run a bit rich high up! In Darwin pull out the choke plates and block off the water choke vac hole! Give a man a fish, he'll eat for a day! Teach him how to fish he'll eat forever!

what just happened?

[clubby2084]

EDIT: I have the carby off my car here if you wanted me to send up so you can try it.

Thanks Trev, have ordered a new fuel pump (should be here by Wednesday) so I'll give that a go first. Thanks for the offer of sending your carb up mate, I may just take you up on that. I'll let you know what happens.


Yeah Suziefox73 I know how much I've spent on this carby and what I could have had instead (and not far off the expense of EFI).. I am familiar with the Weber DGAV carby but, getting a mechanic in Darwin to fit one is nigh on impossible. The mechanics up here can't be bothered "modifying" cars. I am still looking.
I went to 7 mechanics around Darwin asking around who could fix my car. Only 3 said they could fix the carby on the car (by removing it and sending it to the only specialist in town).
And good idea about removing the choke. I have thought about removing it as it's another part of the carby that worked for just 5 minutes after each rebuild. The damned thing isn't working anyway, so...

[LowVp]

i'm starting to develop something similar but it goes like a cut cat when cold but when it warms up it gets a surge around 3000rpm when driven light-moderately but sink the boot in and take each gear around ot 4500rpm you wouldn't notice the problem but just driving normally with some slight hills and it surges / miss / chugs.\


i have replaced coil, plugs, leads, rotor, coil condenser and gone to town with carby cleaner and nothing has changed.


when i was using the carby cleaner i was looking down the bore of the secondaries and noticed they didn't seem to budge when i gave it a boot full, is this normal?

[Trev]

i'm starting to develop something similar but it goes like a cut cat when cold but when it warms up it gets a surge around 3000rpm when driven light-moderately but sink the boot in and take each gear around ot 4500rpm you wouldn't notice the problem but just driving normally with some slight hills and it surges / miss / chugs.\


i have replaced coil, plugs, leads, rotor, coil condenser and gone to town with carby cleaner and nothing has changed.


when i was using the carby cleaner i was looking down the bore of the secondaries and noticed they didn't seem to budge when i gave it a boot full, is this normal?

IIRC they are vac secondaries so the won't operate under no load, check the fuel filter.

[Scoobzd]

Snuffs turning corners

Float level too low or sticking needle n seat

[LowVp]

IIRC they are vac secondaries so the won't operate under no load, check the fuel filter.

fuel filter is less then 2months old and has no visible sediment in it

[altezzaclub]

goes like a cut cat when cold

Doesn't that suggest its running rich? How is the fuel consumption? 7 or 8L/100km? or more?

Float level in the carb? Needle and seat with a bit of dirt in there?

Clubbie if you read this tell us what the outcome was with yours.

[LowVp]

kinda slowly putting one and one together, now is it possible when i encounter the surging its the primaries that are running out of fuel and causing it to ping due to a blockage but when i drop the boot into it the secondaries are open and are supplying enough fuel for it not to ping?