Stalls after fixed time

Is your fuel tank not able to pull in air to replace spent fuel?

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Do you really mean 'it wouldnt turn over', or do you mean that it will not start and run?

In the places I used those words, I mean it would crank but not start.

I never thought of that. This problem started after replacing the pump which is in the tank. From where does it take in air?

On further thought, it takes nearly 10 minutes before starting again. The air would have to be going in very slowly.

Via the pressure-vacuum fuel cap. Try loosening the cap so it's just barely on, then drive around and see if it doesn't stall. If that fixes the problem, then replace the cap. (Alternatively, you can just drive it until it stalls, remove the cap and then try to start the car.)

Ok. Vacuum in the fuel tank is the first place to look. Just loosen the fuel filler cap and see if the problem is solved.

I have also had electrical components that would fail within an almost predictable time after starting and running an engine, including ignition switch, main electronic control module, intermittent crankshaft sensor, etc.

So the thing to do is isolate whether it may be a fuel delivery problem, an ignition problem, etc.

A squirt of starter fluid into the intake when it dies should tell you whether fuel starvation is the culprit.

A spark plug tester is fairly cheap, and will help you find out if you have ignition when the car fails.

These may help you start on the way to a diagnosis.

Thanks. I asked the mechanic about it, and he says there is another air inlet as well, but I'll try it.

What do you (all) think about the hall effect sensor? The mechanic saved the old one in case that wasn't the cause of the problem (which it wasn't, whatever the cause turns out to be). Should I have him put the old one back even though its resistance fluctuated, or defer to his judgement since he saw how much it fluctuated?

fluctuating

When is the last time the distributor shaft rotor button was replaced, it is possible that the secondary voltage is grounding out on the distributor shaft. I have seen on many occasions that the button gets a hole burnt thru it and will intermittently ground out the spark

Glenn Beasley Chrysler Tech

That's not the case.

Was going to be my next suggestion. There is a test for the hall effect sensor that is fully diagnostic:

When the engine stalls, remove battery negative cable *or* take apart the main power disconnect located in the positive battery cable about 6 inches away from the battery. Wait two minutes. Reconnect, crank the engine, then do the 3x key flick (on off on off on) and check the codes. If you get a code 11, replace the hall effect pickup. If you don't get a code 11, the hall effect pickup can be presumed OK.

DS

The mechanic saved

Auto gas caps don't let air into the tank anymore- the evaporative emissions system (charcoal canister, vent valve, purge valve, etc.) take care of that now.

If your gas cap lets air into the tank, the evap system will fail with a gross leak indication.

Or perhaps I didn't understand what you meant by "That's not the case".

You've got that entirely backwards.

The gas cap on the subject model (a Plymouth Acclaim) is of the type nearly universal since 1970 in California and 1971 North America-wide, known as the "Pressure-Vacuum" cap. It contains two calibrated one-way valves (usually in a unitised single-axis valve assembly in the centre of the cap). One of these valves allows air to be drawn into the tank at a controlled rate (that of airflow through an unrestricted 0.040" hole) when a certain negative pressure is reached in the tank. The other valve allows pressure to be vented from the tank when a certain extremely large positive pressure is reached in the tank.

The inlet valve is the one and only path for air to enter the tank to replace the volume of fuel drawn off by the fuel pump. If this valve becomes stuck, a vacuum will develop in the tank and cause stalling problems and -- under certain conditions and with a robust fuel pump -- a collapsed tank.

The outlet valve is the emergency overpressure relief valve and is the path of last resort for fuel vapor to be unloaded before it reaches dangerous pressures. This should seldom ever occur, because the evaporative emission control system routes fuel tank vapors to a storage device -- the charcoal cannister -- and thence into the intake tract where they are consumed. So, it is only in the case of a serious spike in the fuel tank vapor pressure that the cap's outlet valve opens. Such spikes can occur with rapid increases in altitude above sea level and rapid increases in ambient temperature. Of course, such spikes can also occur if the evaporative emission control system is faulty.

No. If the gas cap's inlet or outlet valve is stuck open, THEN the failure you describe will occur.

You understood what I said just fine. What you misunderstood was how the fuel system works.

DS

I'd be checking fuel pressure after it has shut down and make sure its keeping up with the demand .