Stumped! On a Chevy!

ignition
start
engines
gasoline
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sparkplugs

#1

I have a chevy pickup 350 that sometimes starts with no problem and I can drive. Other times it does not start. When I test it, it does crank, I get a fuel in the carb, and it gets a spark.



Since this problem started I have change out the coil module and the ignition switch. What else causes intermittent problems like this???



Please respond!

Thank you!


#2

You don’t mention the year of this Chevy. If it is a distributorless ignition system, look at the cam position sensor. One way to narrow the problem is to use a timing light during cranking when it will not start and see if the #1 plug fires anywhere close to TDC timing mark. You may be getting spark but it may not be syncronized with the engine.


#3

Next time it won’t start spay some ether down the carb and see if it will run on that. This wiil at least tell you if it is a fuel delivery issue.

If it runs on ether, and there is fuel in the float bowl, then the problem is the carb.


#4

cam position sensor on carbed 350 chevy? :slight_smile:


#5

It is a 1985 chevy 1500 silverado 4x4! Thanks