1986 Toyota Pickup starts, runs 2-3 seconds, and dies


#1

I have replaced the fuel pump, and strainer, the O2 sensor, PCV valve, distributor cap, and rotor, vacuum hoses, fuel pump relay, checked all fuses, and fusible links, replaced a burnt wire, and still have the same problem. Any ideas?


#2

It’s been many years but I recall that the fuel pump circuit was powered through the ignition switch while cranking but once started the air flow sensor kept the pump running. It sounds as though your fuel pump may only operate while the starter is cranking the engine, You need a wiring diagram to identify which wires are involved. I have jumpered the wires at the air flow meter to get vehicles running to confirm my diagnosis.


#3

This might be helpful


#4

My guess is that your float bowl is draining, and when you pump the pedal to activate the accelerator pump (and prime the engine and set the high idle cam) its spraying what’s left, and it takes a moment to refill the bowl… during which time the engine dies from lack of fuel.

Try turning the key to ON a few times for three or four seconds each WITHOUT pumping the pedal and turning it to start. If I’m right, that’ll allow the pump to refill the float bowl and the engine will run normally.

I started doing this in my '89 Toyota pickup when I started having the same problem. I never changed the check valve, I just built in into my morning protocol.

Post the results.


#5

The problem might be with the igniter in the distributor.

The Igniter functions the same way as an ignition control module. There’s a start mode and a run mode.

When starting the engine, the igniter allows full battery voltage to the ignition coil. This insures that the spark is strong enough to start the cold engine.

Once the engine starts, and ignition switch is moved to the run position the igniter switches to the run mode. The igniter then drops the voltage to the ignition coil. This done because once the charging system comes on line, the higher voltage would burn up secondary ignition component.

So the igniter may be functioning fine during the start mode, but fails when it switches over to the run mode.

Tester