car runs - for a while

[corvair500]

Car starts right up , idles ok . Drives good for a minute then boggs down and dies . Starts again , dies , Starts again runs 30 seconds , repeats .
1) have new gas tank
2) electric fuel pump
3) engine does not seem to be overheating , very clean under engine shroud

[Dennis66]

Lots of possibilities here. "Electric fuel pump". Where is it located? A pump located in the engine compartment or near it could possibly be sucking air through a leaking fuel line (metal) or hose. All hoses look good with clamps tight? What does the metal fuel line look like? Rusty? If line looks good, was it blown through with compressed air before everything hooked up? (new fuel tank could mean debris got into the line.
Next, check fuel flow. I say undo the line at one of the carbs, have a small container and power up the fuel pump. See what kind of flow you are getting. If you are getting good continuous flow TO the carbs, the problem could possibly be in the carbs. It could be elsewhere too. This is for starters. Because the car starts right back up, I didn't get into the possibility of ignition problems. I will ask you to add if it is stock (with points) or converted to solid state. Dennis

[bbodie52]

There are other possibilities of a fault in the ignition system. Check the condition of the ignition points contacts and the point gap (measured with a meter as DWELL). A faulty condenser that is breaking down can cause some ignition faults. If you have an electronic ignition system (such as Pertronix Ignitor I or Ignitor II, or a FAST/Crane Cams XR-700), they can have some intermittent electronic faults. If you do have an electronic breakerless ignition system installed, let us know what make and model, and we can discuss the specifics if one is present in your car ignition configuration.

An ignition coil can become faulty and passably overheat or produce a weak spark. Even the short wire between the coil negative terminal and the distributor can break down internally and provide an intermittent connection (Clark's sells this wire for this reason).

Part number C530: 60-69 DISTRIBUTOR POINT LEAD

Weight: 0 lbs 2 oz
Catalog Page(s): 75,77(11«),77(19)
Price: $ 10.15



Even the source of voltage that powers the coil on the positive terminal side can develop problems in the aging Corvair. This voltage is delivered from the ignition switch in the ON position is battery voltage (12VDC). It passes through several electrical multiconnectors, including one in the engine compartment (located below the voltage regulator location). The connector consists of two halves of a plastic shell containing eight or more metal pins that connect when the two halves are pressed together. Over the years the metal contacts can become corroded, bent, damaged or loose, or otherwise have an intermittent faulty electrical contact between the two halves. When the wire leaves the connector, it passes through a ballast resistor wire to reduce voltage to the coil. It is present to reduce heat buildup in the coil and to prolong the life of the ignition points contacts (lower voltage reduces burning and arcing as the points open and close). The wire can cause problems, and it can also cause faults with some electronic ignition modules.

So you can see that there are numerous possibilities that could be causing your troubles. More specifics about your ignition system configuration may help us to assist with troubleshooting and fault isolation. And, of course, the problem may not be electrical at all but could be in the fuel system.

[corvair500]

electric fuel pump up near the tank . All fuel lines are ok .
I make the Dist Point Leads for $5 , can even make them in colors other than black . So mine is good .

[corvair500]

All new wire harnesses on car , Coil changed two years ago . points good condition. New brass filters in both carb

[66vairguy]

When you say it "dies" is that at idle? Have tried to feather the throttle pedal to keep the engine running? The carburetor idle and run fuel circuits are different. Need to know if it is an idle problem or a engine running problem.

Did you change the fuel tank recently? When you changed the gas tank did you flush the fuel lines and rebuild/clean out the carburetors?

Also what is the fuel pump wired to? While uncommon I had one car were the fellow wired up the fuel pump to the starter engagement wire so the pump came on while the starter was engaged, the went off with the starter and the carburetors ran dry.

That's all I got at the moment. Good luck

[corvair500]

If it is being driven normally it is like one just shut off ignition switch . Usually starts right back up , sometimes on start up it has to run a little before it wants to drive. Fuel pump is wired through a cut off switch to the fuse panel.
Car starts and will idle for a good while , usually until I turn it off . 15-20 minutes

[Dennis66]

electric fuel pump up near the tank . All fuel lines are ok .

So now to check the fuel flow up to the carbs. There is still the possibility of the gas cap. These need to have a vented cap, otherwise it can develop vacuum in the tank causing fuel starvation. Dennis

[66vairguy]

If it is being driven normally it is like one just shut off ignition switch . Usually starts right back up , sometimes on start up it has to run a little before it wants to drive. Fuel pump is wired through a cut off switch to the fuse panel.
Car starts and will idle for a good while , usually until I turn it off . 15-20 minutes

What cut off switch??? Oil pressure or electronic controller switch?

When you say it quits is that while stopped, engine idling, or when car is moving under power?

Next time the engine quits while being driven BLOW THE HORN immediately. If no horn then it could be the infamous main power wire in the engine bulkhead connector that intermittently goes open. I'm NOT saying this is the issue, but easy to check with the horn test (open main power connection and NO horn) I've repaired a number of these. The BIG red wire on LM's had a barely adequate connector size, but it works UNTIL the connector pins get oxidized or dirty and then the contacts get HOT and the connector plastic deforms and you get an intermittent connection and suddenly the car just quits. May be something else, like the fuel pump controller/cut off switch.

[Scott H]

If it is being driven normally it is like one just shut off ignition switch . Usually starts right back up , sometimes on start up it has to run a little before it wants to drive. Fuel pump is wired through a cut off switch to the fuse panel.
Car starts and will idle for a good while , usually until I turn it off . 15-20 minutes

If it stops suddenly like someone shut the key off, that sounds like electrical. A bad connection at the ignition switch, or bad connection at rear engine harness or bad connection at coil.

Check the stuff from 66vairguy in the previous post too.