99 Sierra 4.3 Intermitent Start

[veedoubleused]

This truck has 110k on it and has been a good runner so far. Plain Jane with no options. A couple of mths ago it failed to start on a wet day. Changed the plugs and wires with no effect. Messed around for a while with a heat gun drying off wires and got it to start after alot of cranking.

The problem is intermittent and after it starts once it will start all day but maybe not the next day. I finally discovered that by placing the heat gun directly toward the two fuel lines where they enter and exit the intake manifold that the truck will start after about 15 seconds of heat, stumble a little and then run fine. My mileage has been about 16. I cant remember the code # but it displayed a 'right bank running rich' message.

I ran a fuel pressure test that showed 58 psi when priming and 63 when cranking. I thought that was ok.

Any thoughts?

[veedoubleused]

Is it possible or likely that the applied heat is distorting the multi-pin electrical connector for the injectors? When it wont start it really sounds and looks like a timing issue. I have fuel and spark.

Is there any other info that would help with diagnosing the problem? Also, I have spent a bunch of time reading and searching the forums here. Any suggestions on what search terms to use?

Thanks.

[veedoubleused]

As it turns out the problem was the coil and the heat gun was close enough to make a difference.

Thanks to anyone who spent time thinking about this and I apologize for the red herring.