99 1500 5.9 has spark and fuel....no start. Stumped

[Tonyg1103]

it cranks over, acts like it wants to start but won't. I can hear fuel pump in tank, fuel pressure is good at rail, coil is sparking, I've pulled each plug and turned it over and they're are all sparking....plugs were all pretty wet with fuel when I pulled each. I've even sprayed ether in TB and still nada. Would a faulty cam sensor (pick up coil) or crankshaft sensor cause these symptoms? Or would yhere be no spark or no fuel with faulty sensors? Coolant sensors? Thanks in advance....tony...hoping for suggestions to try rather than just throwingparts at it.

 

[dudeman2009]

Crank sensor will disable ignition, but a cam sensor going out won't always. I'm going to guess that it was working in the past but has stopped for no apparent reason.

Does the engine sound like there is no resistance while cranking, or does it labor a little bit when cranking? Have you tried to start it with the air filter housing removed?

 

[Max78]

If you have spark and fuel pressure but its still not starting means that your injectors are not firing, the cam and crank sensor work together to fire the injector.

I would swap the ASD relay under the hood with the AC relay to see if that changes anything, then I would look at getting a scanner if you dont want to throw parts at it.

 

[nc bogger]

The asd relay circuit, cam position sensor can cause this cause it has to me before. Last time it happened though I found a faulty ecu by doing the cluster test and it read no info on the cluster display and the scan tool. My crank position never throws a code when it fails either and causes unusual issues.

 

[ouch1011]

Have you checked for fault codes? Have you checked for spark at the spark plug or just out of the coil? Bad ignition coils are common on the 5.2/5.9, and it may be good enough to spark right at the coil tower but not when it needs to make it all the way through the wires, through the gap at the cap/rotor and out the gap at the plug while under pressure. Broken flex plate can also cause the fuel/spark to be present, but the timing will be wrong if it cracked and shifted.

 

[Mikecollins]

If you have spark and fuel pressure but its still not starting means that your injectors are not firing, the cam and crank sensor work together to fire the injector.

I would swap the ASD relay under the hood with the AC relay to see if that changes anything, then I would look at getting a scanner if you dont want to throw parts at it.

He has wet plugs

 

[Mikecollins]

I know it sounds wierd but check your coolant temp sensor also, the damn thing apperently tells the pcm that your engine is 40 below when it dies and so the pcm will flood it with gas trying to warm it up faster, also check you head to head to firewall ground strap

 

[mechanicmark]

If no codes showed up, what happened on my 98 5.9 V8 was that it hit -15 one night here in Northern MI and my fuel tank was at an eighth of a tank. Too much water in there and the gas froze. After troubleshooting the sensors and the ASD relay, I put some HEET in the tank, but no start. Pulled the plugs, and they were wet with ether. Either bake off the ether in a JUNK OVEN, not your household one( nothing will taste right) or get new plugs in it. Fired right up after that and gassed up.