03 Golf no start after sitting for 6-8hrs

As the title says , I park it overnight or for 6-8 it does not want to start. Cranks over really fast like it Gs no compression and or is out of time. The first time it did it, I checked the timing belt etc. I opened the air box and shot some WD-40 thru the MAF meter and cranked it and then it slowly started. Ran fine the rest of the day. Parked it and then wouldn’t start again . This time I just cranked it for a minute or so straight and then it started. Injection pump have some kind of return valve letting it drain maybe? It had fuel in the clear line to the fuel filter. Any thoughts? Thanks

You have an air leak, probably the O rings on the T in the top of the fuel filter, or elsewhere in your fuel lines.

That makes sense . I just don’t understand why it doesn’t do it every time? Stated this morning just fine. If it is leaking air, wouldn’t leak fuel when running? Thanks again for the reply

More fuel in the tank? If a small leak is letting air in a full tank would be less of a problem than an empty. Also maybe temperature related since seals are a little softer when warmer.

A leak before the pump doesn't see positive pressure so won't leak fuel but even the pump seals can let air in but not leak fuel.

Before you dive too deep into the fuel system, check your anti-shudder valve on the EGR. If it cranks like there is no compression, it's because it's not allowing any air into your intake tract. Mine used to do this randomly when the EGR was getting some gunk in it, causing the flap to stick closed.

It cranks like a gas motor with no spark plugs in the holes. Just spins and then slowly tries to come to life. Even when I used WD-40 down the intake it was still slow to pull enough air/fuel to start. I don’t mind it being hard to start etc. but being stuck somewhere on the side of the road sucks. I drive 100 miles each way to work 3-5 days a week.

I like the anti shudder sticky as an interweb guess.
Don't spray stuff thru your MAF, it has a hot film sensor (MAF clean is O.K.)

It does seem like a possibilty except why the time relationship? The ASV opens immediately after cutoff.

It isn't like it waits for the next startup to open.

Edit: In last paragraph Is: open, Was: closed

That's right, it closes when turned off, then falls back open.
It's the different crank speed I can't suss out. First thing I think of is snapped belt, but not this one. Interweb guess it's intermittent. Not hard to rule out, next time cars been sitting, pop the hood first and exercise the thing.

KLXD said:

It does seem like a possibilty except why the time relationship? The ASV opens immediately after cutoff.

It isn't like it waits for the next startup to close.

Click to expand...

Mine would close on shutdown and stick there until I tried to start it... which was usually 6+ hours later.

I'm not saying that's the definitive issue, but it seems relevant to check. I agree with others to not spray things into the intake tract... if you're spraying in at the MAF, that spray has to travel through the turbo and all intercooler piping before it makes it to the actual intake on the engine.

Good point.

Reading comprehension fail on my part. I didn't pay much attention to the fast cranking and I see he doesn't say it starts fine when hot. I ass-umed it did.

I had the ASV stick shut a few times over the years.
First few times I was going nuts trying to track it down.
Even replaced relay 109. Now I have a spare.
After the 4th (or so) time I discovered it would start if I slammed the hood closed.
Finally caught it stuck closed.
Cleaned it and it was OK.
Now I wipe the area inside of it with a shop rag with a bit of brake clean on it when I have it open.

PD engine?

I would check this:
http://pics.tdiclub.com/data/517/PD_fuel_delivery_check.pdf