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Inertia Cut-Off? - Non-Running 360 GLT

Posted: 07 Apr 2011 08:07 pm
by brickie501
Want to separate this from my project thread as a passing phase :(

Thought I had done the best I could before 6 month layup - using a fuel additive (trying to preserve petrol a bit) and disconnecting battery - but it obviously was not good enough...

... it was running well before but now my GLT will not start.

Have not seen it myself yet but going up this weekend with tame mechanic (my brother) in tow and want as many ideas to get running as possible before we set off.

Work so far has been on getting fuel through, which bypassing the fuel pump relay did, but there is no spark either.

Mechanic who has looked at it suspects Crank Position Sensor so am trying to get a spare but I can't quite understand why the relay and CPS would fail simultaneously when it has done no miles? Are there any faults 300s suffer, particularly after being laid up, that would give these symptoms?

A thought my brother had was that an inertia switch (crash cut-off) functioning would cut fuel and spark. Is there such a thing on an '88 360 GLT?

Many thanks

Re: Inertia Cut-Off? - Non-Running 360 GLT

Posted: 08 Apr 2011 11:34 am
by Ride_on
I don't think there is an inertia cut off, but the lack of a cps signal (from a rotating engine) will cause the fuel relay to stay off, that is the main crash safety mechanism, so you should not bypass it.

The ignition is pretty self contained, cps+renix module + distributor + power. Check power first.

Re: Inertia Cut-Off? - Non-Running 360 GLT

Posted: 10 Apr 2011 07:07 am
by brickie501
Ride_on wrote:... the lack of a cps signal (from a rotating engine) will cause the fuel relay to stay off...
Thanks Ride_on ... that was it.

Other mechanic must have shorted the pins on EFi control relay wiring to get fuel but, without CPS signal, there was no spark being created either so it still wouldn't fire.

CPS failed impedance test, 220 Ohms +- 60 (thanks Haynes manuals) and substituting another sensor confirmed the fault as it then ran :D