2003 silverado 4.3 hurricane problems

[John Macrini Jr]

So I'm usually able to get on YouTube or something and diagnose my own problems and make my own repairs but I have been at this one for 3 days now and I am at my wit's end.

As of right now the truck will only turn over but wont start. 

 

I've got a 2003 Silverado with the 4.3 V6.

Hurricane Harvey got me pretty bad but it had some flood water issued all of which I thought were fixed.

 

So here's what I have done so far.

Brand new complete exhaust including 4 new o2 sensors.

Drained tank (no water) New fuel filter (s) and good pump.

New distributor and rotor.

New pcv valve

Cleaned mass air flow and put new air filter in.

I bought a spark tester and am getting good spark through the coil and through the plug wires.

After trying to start it 4 a bit the tailpipe smells like pure gasoline.

I'm stumped!

 

Also the water did not make it into the crankcase or the Transmissions. The water only made it up high enough to ruin the exhaust in the oxygen sensors that's about it.

Any ideas? 

Thanks.

 

[Jsdirt]

Try cranking it in clear flood mode (pedal to the floor) - this will kill the injectors so as to not compound the issue, since it sounds like it's flooded.

 

If that doesn't get her running, remove all the plugs, disconnect the ignitor to kill spark, & crank it over. That'll clear out any excess fuel.

 

There is a slight possibility that the engine sucked water in from the exhaust, depending on how far up the tailpipe the water went. It's a stretch, but it's possible.

 

Make sure the distributor was installed correctly - you may be 180° off, with spark occurring on the overlap stroke instead of the compression stroke. This is where my relic tools come in handy - a timing light. 

 

Also make sure all the salt water is out of the o2 sensor connectors - they will turn green and corrode pretty quick.

[Motor City Rick]

Did "any" of the water touch any of the electrical / electronics???

[John Macrini Jr]

2 hours ago, Jsdirt said:

Try cranking it in clear flood mode (pedal to the floor) - this will kill the injectors so as to not compound the issue, since it sounds like it's flooded.

 

If that doesn't get her running, remove all the plugs, disconnect the ignitor to kill spark, & crank it over. That'll clear out any excess fuel.

 

There is a slight possibility that the engine sucked water in from the exhaust, depending on how far up the tailpipe the water went. It's a stretch, but it's possible.

 

Make sure the distributor was installed correctly - you may be 180° off, with spark occurring on the overlap stroke instead of the compression stroke. This is where my relic tools come in handy - a timing light. 

 

Also make sure all the salt water is out of the o2 sensor connectors - they will turn green and corrode pretty quick.

O2 sensors, cats, and muffler all brand new.

I guess I should have added I got it running and it was running beautifully for almost 3 weeks after all of the initial work I spoke about. Whatever is going on is either a new problem or something intermittent that finally went out.

I'm trying to get a computer over here today as we think it may be the camshaft position sensor.

[John Macrini Jr]

3 hours ago, Motor City Rick said:

Did "any" of the water touch any of the electrical / electronics???

The water didn't reach the spark plugs. For the most part no unless there was or is a sensor below that area.

 

[John Macrini Jr]

Ok so the crankshaft sensor was not the issue. Its looking like it may be an ignition problem. Seems like the plugs are getting a really "weak spark" and cylinder 5 looks to not be firing at all.

[John Macrini Jr]

Also the computer yielded no results as I had the battery disconnected when I was working on it so no codes ?

[Jsdirt]

Some good troubleshooting steps here: 

 

http://easyautodiagnostics.com/gm/4.3L-5.0L-5.7L/ignition-misfire-diagnostic-tests-1

 

[John Macrini Jr]

42 minutes ago, Jsdirt said:

Some good troubleshooting steps here: 

 

http://easyautodiagnostics.com/gm/4.3L-5.0L-5.7L/ignition-misfire-diagnostic-tests-1

 

Yes that site is one of my main resources.

Lots of good information there.

Thank you