# Chevy 4.3 no start( no fuel & no spark)



## ma84lx (Nov 23, 2007)

Have a 92 1500 Chevy truck with a 4.3, that will crank, but not start. First noticed no fuel out injectors when cranking, checked for bad fuel pump, by sparying starter fluid in the TBI, didn't work. So I checked to see if it had spark, no spark either. Check the fuses and realys and all are good. 

Started testing according to the Haynes Manual.. Checekd coil, pick up and igntion module. Coil checks out good, had igniton module tested, and it was good, and the pick up OHM'd at 856ohms.. 
Where/what else can I test?????


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## qldit (Mar 26, 2007)

Good Morning ma84lx, your problem suggests you have no power to the entire ignition circuit.
The computer and all it's peripherals is generally on a common fused circuit and the main fuse is usually located in the under-dash panel. (Usually labelled IGN etc.)

The actual fuel pump is controlled by a relay that is initiated by this same circuit, but the "grunt" power for the pump is alternately sourced.

In that your entire system appears to be unpowered, use a meter to ensure power is available on both sides of the underdash IGN fuse.

This may possibly involve more complicated circuit components but generally that power is supplied from a master fuse or fusible link system in the engine compartment.

Power could be expected to passed to the complete ignition system from that underdash fuse via the ignition switch. 

You will really need a simple voltmeter to analyse this problem.

Others will have different ideas.

Cheers, qldit.


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## ma84lx (Nov 23, 2007)

Thanks for the info,,,

But it turned out ot be the DAMN module.. Had it tested 4 times in a row when I took it up to the parts store, the 1st time. After testing everything the haynes manual said, I decided to take module to be tested again,, and it tested good. But I bought a new one anyway, and BAm truck fired up...


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## qldit (Mar 26, 2007)

Good Afternoon ma84lx, well done!
You have probably discovered that testing these kinds of components with simple testing devices is not very accurate.

Those Haynes manuals are usually pretty decent information, but the problem with a lot of this complex solid state stuff is that the only real way to check operation is by replacing the item with a new one.

Ignition modules can be damaged by simple things like disconnecting sparkplug leads or having defective leads apart from so many other things, like using "jumper leads" for starting.

Again Well Done!

Cheers, qldit.


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