Hi. I have a 2001 1500 2wd 5.9l, everything stock. My truck starts fine when cool but will not start once it warms up. It also is idling a little rough now. I recenlty replaced the water pump and clutch fan, thermostat and coolant temp sensor. Then replaced the idle air control and throttle position sensor. I got several misfire and a camshaft position sensor errors after that and when I went to look at the distributor noticed corrosion on several of the wires and the center post on the cap. I replaced the cap and rotor and put in all new wires and spark plugs. I was suffering from a loss of power and poor mileage from the misfiring and this fixed that. My problem now is that after I drive the truck and it warms up it starts to idle a little rough and will not start until it has sat for a bit and cools back down. I am getting no codes now. It clearly is a heat issue but i can't think of anything that would make the truck idle a little rough once it warms up and keep it from starting but doesn't kill it while I am driving it. Could a sensor cause this?

 

Pre cat o2 maybe. Also read the plenum sticky on top of forum.

 

I replace both pre cat O2 sensors today, no change with the starting issue

 

Crank sensor?

 

"I got several misfire and a camshaft position sensor errors ... "

Then go ahead and replace the cam sensor. If that doesn't do it, test the crank sensor as outlined in a thread I started called "Interesting spark problem". Electronic components are often involved in temperature-related problems like yours. My crank sensor would start to act up when it got cold out.

 

Crank sensor or cam sensor it sounds like.

 

Funny thing is that it started starting this morning after getting up to operating temperature. The last thing that was done was the pre cat O2 sensors but it still wouldn't start yesterday after they were changed. It's starting now but I still have a rough idle. I went ahead and changed the ignition coil this morning but the rough idle didn't change. Thinking of the other O2 sensors next since they can affect idle and potentially starting if they are messing up the PCM with bad readings once they warm up.

 

Your problem is sounding more and more exactly like mine. Take out/test the crank sensor. You can also check the strength of the spark at the ends of the plug wires. Zman hates this, but I just stick a well-insulated screwdriver into the spark plug boot and hold it a short distance away from a good ground. See if all the sparks can jump about the same distance, with the same intensity, and with the same regularity. If they don't, my money is on the crank sensor.

 

I agree with the crank sensor, Don't know why I didn't say it to begin with. When they start to fail, it's usually after the motor is warmed up. However, I would also try unscrewing the o2 just to see if it starts and stays running after warm up. Because it could also be a failing cat. When the motor is cold, bang on the converter and see if it rattles.

 

I replaced the crankshaft sensor, no change with starting issue. I am doing the pick up coil next but I don't see how this would prevent it from starting once everything was warmed up. I have read in several places about the camshaft sensor for the truck and I did originally have a camsheft sensor code but no auto part supplier list a camshaft sensor for my truck. I found a exploded view diagram of the distributor and it labels the pick up coil as the camshaft sensor which is why I am replacing it. Is there any type of sensor in the transmission that would prevent the truck from starting? This is still clearly a heat issue but I am running out of things to replace