Question: 1990 intermittent starting problem

[too many toys]

This is base auto coupe with 250k miles on it. I've done all the normal checks BUT unless you turn the key to the "on" position 2or3 times, and sometimes not then, the car will crank but not start. It acts like it is not getting fuel, but it is. I've been told the anti theft may be the culprit, but no-one knows how to dissable it. ANY ideas on the START issue or the suspect ANTITHEFT culprit? Thanks

 

[Schrade]

Welcome to the boards!

VATS anti-theft, when activated, will NOT allow the motor to turn over. If the motor turns over, NOT VATS. Pocket lint on the key will change the resistance of the chip, but again, VATS activation will NOT allow the motor to turn.

Do a fuel pressure test. Static, and dynamic. Static = key on, don't start the motor. DO observe how long the pressure holds until 0 PSI. See youtube for pressure test vids. Just like checking tire pressure.

Dynamic pressure is pressure reading AFTER motor has started. You don't need this just yet, regardless if you do it or get a mechanic to do it.

If you get a mechanic to do it, WATCH the STATIC test, and don't fall for "You MIGHT need a fuel pump." Post back the readings.

 

[vetteoz]

VATS anti-theft, when activated, will NOT allow the motor to turn over. If the motor turns over, NOT VATS..

There is also the injector enable component of the VATS; if that had a intermittent fault it would allow cranking but not fire the injectors.
The ECM also has to see the signal from the distributor whilst cranking to pulse the injectors.

 

[vigman]

Fuel pump Oh By the way

The pump wiring on the interior of the gas tank had a little white RF noise reduction module. This bit of electrical wonderment sometimes opens up...

Open up the gas cap.. have someone turn the key to the on position.. make sure you hear the pump running for 3-4 seconds...

If it doesn't... this starts you down the path of repair!
Thanks

Vig~