Crank no start

[MassHoe04]

Just throwing out a question to maybe draw out some more answers...
If plugs were found to be wet after cranking, would the addition of starting fluid allow the engine to start and run, as it has been?
Would that be possible? I don't know. What say you all?

Like I said, just seeing what pieces we can pull together and get closer to an answer.

 

[rockola1971]

Just throwing out a question to maybe draw out some more answers...
If plugs were found to be wet after cranking, would the addition of starting fluid allow the engine to start and run, as it has been?
Would that be possible? I don't know. What say you all?

Like I said, just seeing what pieces we can pull together and get closer to an answer.

I wouldnt expect this to be an igntion problem since it runs (I assume ok) on starting fluid. I have seen engine run on fluid and be out of time but wont start using gas via the injectors. So I would expect this to be an air, timing, fuel delivery or passlock problem. Could of course be that pesky Crank position sensor too. It is plausible that engine is NOT getting enough air and start on fluid but not gas via the injectors too. This is an interesting gremlin but I bet it ends up being stupid easy to diagnose. Just gotta do it in order.

 

[steveo1]

I would recommend doing a cranking test and then pull a couple spark plugs and see if they are wet with fuel nodes smell like it. That will help direct your diagnosis as well. I'd maybe inspect 2 before trying this: burning them clean with a small torch reinstall, test crank a couple times, and then remove again and inspect.

If they are covered in fuel, then you know spark or air is gone (it runs on starting fluid, so I'm suspecting air is OK). If there is no fuel coating or smell, then you have a fuel problem.

I'm not ruling out the PASS LOCK, but like stated above, you'd need a better scanner to dig into that one. Hope this helps!

The plugs that Re in it are new the engine has only run once or twice on starting fluid with these particular plugs in the truck..far as the crank sensor it has been replaced and has not run but once or twice with that installed either... I'm currently going over the grounds on the car.. removing then wire brushing and replacing just to eliminate them as a possibility..it's coming down to I can answer what it isn't rather then what it is...process of elimination I reckon

 

[B-train]

Was the crank sensor bad? If it was a shot in the dark, would it be worthwhile to put it back in and try the original again since many parts have been changed? I think so many things have been looked at, has it muddled the original problem? I'm at a loss without seeing it at this point.

To the question would it run on starting fluid if the plugs were saturated with gas? I don't think so because if they were saturated, then that means there is unburnt fuel and you are adding MORE fuel to burn. Unless the timing is way off and the injectors timing is useless then I could see it being possible.

I still think a quick sniff test of plugs and an flow test of the pump post filter is a good place to start.

 

[MassHoe04]

Was the crank sensor bad? If it was a shot in the dark, would it be worthwhile to put it back in and try the original again since many parts have been changed? I think so many things have been looked at, has it muddled the original problem? I'm at a loss without seeing it at this point.

To the question would it run on starting fluid if the plugs were saturated with gas? I don't think so because if they were saturated, then that means there is unburnt fuel and you are adding MORE fuel to burn. Unless the timing is way off and the injectors timing is useless then I could see it being possible.

I still think a quick sniff test of plugs and an flow test of the pump post filter is a good place to start.

I was being the Devil's advocate on asking if the engine would start, if the plugs were soaked with gas. I didn't think so, but the possibility of timing being off so bad that it could briefly start on starter fluid and still be soaking the plugs while trying to start without starter fluid does make sense.

Being on his third new fuel pump, I would say not impossible that it is the pump... But the odds of being a pump issue in the first place is probably slim to none from the very beginning.
With that, the issue is likely to be found ahead of the pump, which could also include truck side of the harness and connector attaching to it.

The fact that it has fired off on starter fluid does show some sort air intake action and at least a bit of sparkage going on. It did something at least.
Stumper!

Maybe it is the new crankshaft sensor that was just put in or the camshaft position sensor.

Live data or a bi-directional scan tool would be one of the best things to have help out right now. Being able to see all the parameters of what is happening (or not) would be really helpful.
If that kind of scan tool is not an option, I am sure @rockola1971 or some of you ASE experts will be able to walk OP through the process without one.

Maybe a sensor connector got knocked off or damaged during repairs or while trying to diagnose this issue. Check all connections possible. maybe it will be something stupid and cost nothing (more) to fix.
Fingers crossed!!

 

[corvette744]

Take it to a reputable mechanic.You have done what you could do hopefully this is not your daily.

 

[steveo1]

Taking it to a mechanic would be great.. it's my daughter's Tahoe that I gave her couple years back.. the value of the car verses what I'll likely spend with a mechanic done way out...I know that's where it needs to go but honestly at this poi

 

[steveo1]

When the truck originally went down it went down with symptoms of a bad pump...

Ran really rough, choked on it's self at idle, dying out and hard starting sometimes in middle of intersection until the last time ..last time I got into it to move it..it starts runs really rough..smelled of unburnt fuel...very Rick smell accompanied by a small amount of black carbon like smoke..

Really think timing is ok.. how can I pin point or eliminate the pass lock system...I need to find a resolution to this asap...thoughts ?

 

[steveo1]

What about running a jumper wire from battery to a fused positive to the fuel pump...let it run constantly would that diagnosis anything far as pump.....basically hardwire it direct to battery eliminating the ignition side of powering it

 

[steveo1]

I've pulled few plugs after trying to start And no fuel seems to be mJing it's way to the plugs there definitely not saturated like I would have thought them to have been