I have a Buddy that bought a 83 and had the dealer do a tune up to it
new wires cap plugs set timing change oil replaced external fuel filter

he says the car will run very roughly from time to time where he has to drop down into third gear and it is still bucking and will stall at lights etc

It sounds like a carbon problem from what Ive read and I have told him to run the car at high revs and we will try the water spray down the carb thing Saturday

But the car was Idle for a few years, he has run 3 tanks of gas through it and fuel system cleaner but how do you get to and replace the in tank fuel filter?

BTW I noticed the air pump was not running a belt but I think the dealer replaced that as well

 

Not sure, but unless the fuel tubes are removeable as a unit, it may not have an intank filter screen. If that's the case, then rod out the supply tube and clean the tank. This is easier to do with the tank dropped.

 

If this all started when he took it in to get serviced, then I would suspect that something critical was changed. If the air pump has been hooked up, then maybe the system wasn't functioning correctly before and that's why it was disconnected. Something along those lines.

Check the timing yourself, don't trust someone else to get it right. Set the idle mixture too. How is the idle speed? You can also adjust the accelorator pump, just make sure that the linkage starts to move as soon as the pedal is depressed.

Just start taking a good look at what they did. Maybe try taking the belt off the air pump and see how it runs without it...

 

Just did this, reinstalled the tank today, the fuel pick up is located on top of the tank, you have to drop the tank to get to it.

As Kentetsu said, this sounds like an engine issue, but to check your fuel remove the fuel line delivering the gas to the carb and turn the ignition on, run the fuel into a container and check the quantity over a set time period to ensure adequate delivery.

 

We will check all these things , he says it is really running ragged
so if we drop the tank we can access the filter?
he says right around 3000-4000 is the trouble spot secondary linkage issue maybe?

 

What you have in the tank isn't really a full-fledged filter -- it's a screen on the pickup tube that prevents large debris from clogging the pickup tube. If debris is your problem, the culprit is most likely in-tank corrosion -- a lot of it. If this is your problem, I recommend replacing or reconditioning the tank. Once the corrosion gets going, it's tough to stop.

Before you do any of this, however, I'd T-in a fuel pressure gauge to your carb inlet line and tape it to the windshield (use one of those cheap vacuum / fuel pressure gauges from your parts store). Check to see if fuel pressure is low when the car is running poorly.

This is a relatively easy check that will positively diagnose your issue if it is related to fuel supply.

 

Also, an easy and regular problem with this symptom is the in line fuel filter, they cost $3 put a new one in again, its probably loaded with crud from the tank.

Does your car have a fuel tank drain? If so run it low on gas and then drain it, check the contents for crud, a strong magnet located around the drain plug for a day or so will bring the crud to the drain area.

The inline fuel filter is located by the fuel pump, in front of the drivers rear wheel under the body.

 

Now there is a shade tree trick I have not heard of, who's the Legend now?

 

Hehe kept my crud filled leaking tank running for a couple of weeks while I got the new one ready.

Nice to get one right once in a while.....lol

 

We are going to replace the filter before the fuel pump
the car runs better (when it runs better) so it sounds like
he is getting a high flow filter pluggage
He also has some idling difficulty so we will look for Vacuum leaks
esp aroung shutter valve and hoses
we will also attach a FP gage, and run some Sea Foam through the
tank, and clean the Carb thoroughly.
Cant really drop and clean/ seal the tank for a few weeks
Or rebuild the carb but we are going to autopsy the old fuel filter
and see the amount of crap that is has in it
and hopefully it will be running much better

 

Sounds like a good plan man.

 

We changed out the fuel filter, shot the crap out of the carb with carb cleaner
put a little tension on the Idle screw, and put Sea foam into the half tank of gas
the Accelerator pump is Kaput absolutly zero pump shot even when I stroked the plunger by hand, and it looks like the secondaries were varnished shut, I could not see any movement of them at WOT in neutral (Kentetsu says you will not see them open without load).
Long story short it will start with out the choke, and other than the off idle stumble from no AP she is driving sweet, pulls good,revs high, I even put her in 5th at 1100 and she pulled on up from there with out any trouble.
we plan on getting the Carb rebuild kit Sterling recommends ( which one is that again?) and going through the Carb in a few weeks when he can have the car down
and I will put a vacuum pump on the Vacuum actuator for the secs to see if they open or not.
BTW there was about a table spoon of very fine light brown material in the filter
more than enough to cause a high flow fuel starvation, he is going to monitor the filter and change it out at the next sign of debris he has 3 more on hand.
this will turn out to be a very nice little car

 

Yeah figured it was fuel filter, change them about every 3 months if you drive regularly, keep a spare in the car at all times, if she starts to starve, change the filter.....

 

it was a night and day difference
she will pull to 6500 now where as before wouldnt break4000
without bucking snorting and stalling
when we go through the carb and esp renew the accelerator
pump it will rock