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Truck runs on cng and unleaded,runs fine on cng,when switched to unleaded dies ,security light on,need to turn off

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  • naile
    naile May 11, 2010

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2001 chevy cavalier cng auto theft light won't go off on panel after car turn off. runs battery down

the system is bad.
security /thieft.
or a relay is stuck,
got a voltmeter we can find it. otherwise, get it fixed.

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Dec 08, 2012 | Cars & Trucks

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I have a 2002 Chevy Cavalier that's a Bi Fuel. When my CNG tank is empty it doesn't want to run on regular fuel. Is this a problem with the switch?

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I just replaced the ignition switch and lock in my 2000 alero and now it starts and runs fine but the security light is on and stays on. How do I reset this security light?


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I have 2000 ford contour with cng where are the

I also have a 2000 CNG Contour, and my fuses are bolted to the driver side strut tower under the hood. It is between the strut tower and the power brake booster. The fuses are covered with a black rubber boot, and the rubber boot is secured with a small zip tie. Just cut the zip tie, remove cover and you will find a few fuses.

SGT Jensen

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My cng truck runs fine on nat gas,when switched back to unleaded gas truck stalls,what is the fault ,how is the two computers controlled,what deos the switch turn off.

tune up for gas is different in the timing compared to lead or unleaded fuel by upto 12 degrees
the two computers control the engine management & the transmission
when you switch between nat gas & fuel a solenoide is activated to block ether so they cant mix
if they did mix your gas would freeze the fuel & you would see the fuel pipes start to get iced up
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F350 no start

I have a feeling you got a wholed of unleaded fuel or bad fuel
I drive a diesel box truck the station I always took it to the fuelman put unleaded in the diesal tanks and the truck just died it had to have the gas tank completed drained and cleaned out but also ask yourself how many miles are on it and when was last tune up and if you live in a cold climate I recommend a heater block plug

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