Help! 04 V8 EB won't start! Fuel/Spark/Compression & starter ok... any ideas?

[enigma9o7]

130k miles, maintained, usually very reliable. Stalled while driving, nothing unusual. Wouldn't turn over so had it towed home.

First thing I found was low battery (12.05V), it was 5 years old so I bought a new one, thinking either it or the alternator was causing the problem. Now it cranks but won't start, have kept the battery fully charged with charger now. Will check voltage to see if alternator problem once started, but that's not really my big issue, since i can't even start.

I've used ForScan to check fuel pressure at rails, seems ok, ~280kPa before I turn the key and goes higher while cranking.

I ran every test (except those that require engine running) while in forscan. The only DTC's are one for IM readyness (from replacing battery) and one about my 4WD switch. I assume that's unrelated but I'll have to check out 4WD sometime, I haven't used it in years.

Checked compression with a gauge, all fine, around 110-140. Verified spark with a in-line light tester thing.

Tried pulling ABS fuses to force failsafe mode. Still no start.

Forum searched for related issues, nothings seems relevant - for example my stock LED does what it's supposed to, tried random things I read that seem unlikely like putting into gear and back to park

 

[shucker1]

How did the spark plug look when you took them out?

Wet? Perhaps a load of bad gas?

Could the engine just be flooded from so many start attempts?

Perhaps pull the plugs out, disable the fuel pump by pulling the relay and ventilate the engine by cranking it over a few times without the plugs?

You then put everything back together and see if it wants to start.

 

[enigma9o7]

Last fillup was almost 3 weeks ago, so don't think it's bad gas. This is the second weekend I've been trying to solve this so I really don't think it could stay flooded that long... I just spent hours searching for ideas and still have nothing really worth trying tomorrow, so I'll pull all the plugs and let it breathe a while tho just in case if no other ideas present themselves, and check out the plugs, I put them in summer 2015 25k miles ago so they should be good, but we'll see... Also gunna record compression numbers exactly too (as I read someone saying if one side is worse than others could be timing issue, and I didn't pay much attention as long as they were normal) while they're out. And try jump starting, as I read somewhere that if my alternator is bad a charged battery may not be enuff to run (which seems unlikely, but gotta try something).

 

[shucker1]

And try jump starting, as I read somewhere that if my alternator is bad a charged battery may not be enuff to run (which seems unlikely, but gotta try something).

That sounds like crap to me too.

An alternator really doesn't make any power until it gets to about 1500 RPM itself so how is it going to do that while starting up?

Think of your battery as a storage tank. Alternator is there to keep the "Tank" full.

Also gunna record compression numbers exactly too (as I read someone saying if one side is worse than others could be timing issue, and I didn't pay much attention as long as they were normal)

You need to look at everything to solve the puzzle.

 

[enigma9o7]

Still nothing. Checked a few random things I read about, but nothing. I pulled all the plugs at once to "air it out" incase any gas build up , and measure compression accurately on every single cylinder, and put it back together with brand new plugs. Chugged a second after letting of ignition but won't start, had that happen before. So no change.

Compression is kinda all over the place but not like one side has all low numbers or something to indiciate timing issue... in order (1 to 8) my compression numbers
180 118 120 112 112 130 165 101

Please, any ideas appreciated, I dunno what to do next. It should be running damnit.

 

[domct203]

Did you try starting fluid as mentioned on your other thread?

How to check fuel pressure? How to Force Limp Mode?

 

[enigma9o7]

No. Don't have any. But seeing as I appear to have fuel, and it does sputter a bit ocassionally when trying to start, I didn't think it was worth a trip to the store. But I guess I should try so I'll get some.

 

[enigma9o7]

I assume spraying gas into the throttle body (from a squirt bottle) would determine the same thing as using starting fluid?

 

[shucker1]

No it will not.

Starter fluid contains Ether which burns better than gasoline.

 

[enigma9o7]

So what would it prove differently? If it runs from either one, then I have a fuel delivery problem... if it doesn't do anything different with either one, then it's not a fuel delivery problem. What would it mean if it only ran from starter fluid but not sprayed gas?

 

[Jeremy Nixon]

Maybe bad coil pack? Or fuel filter?