Well i've ruled out the battery. It was right around zero this morning and it took about 4 tries to get it to fire I'm thinking of trying my old wires again, maybe start over with the ignition parts..i don't know.

 

Update: a mechanic buddy of mine suggested to change the dist. cap again because they're crap and known to allow moisture in(like my last one) so i tried that... cheap part so i didnt' mind. No change.

But, in my search for the hold ect sensor i found that i do indeed have a block heater ! So..the next cold night i'm plugging her in to see what if any change that brings. Of course now it's supposed to be warm for the next week so it might be a while before i get my next update.

Do all the trucks or maybe zr2's come with the block heater? The cord was hidden pretty good..this is the first time i have seen it.

 

Update: Haven't had a cold enough day yet so i haven't plugged in... but my mechanic buddy told me this... "Also there is a cam retard that needs to be adjusted by grinding the distributor hold down and setting with a scanner. Common on high mile 4.3's to be out as much as 18 deg". He also mentioned something about slack in the timing chain...

Does this sound plausible? Given that I have a 'backfire'ish sounding noise just before i get the thing to fire makes me think timing could be related to this problem...

 

Well, that is a new one... Slack in the timing chain is one thing, but you would have to have a hell of a lot of wear in the distributor to get it out 18 degrees...

 

Yeah i agree. I trust my friend, although a statement like that could mean he has only seen one out that much. I do have 287000kms on the clock... he said he'll scan it for me friday so we'll see where we're at.

This morning it was 12 deg here and the truck fired up first time. It's definitely temp related...and not moisture related.

 

If it is temperature related, you can definitely rule out mechanical problems (ie worn distributor or stretched timing chain).

 

So timing being off wouldn't affect the startup differently in colder weather vs warmer? (honestly i'm asking because i don't understand).

I dont' know what's left? All the ignition parts other than the distributor are fairly new. Plenty of fuel pressure, air filter is new, fuel filter recent... what's left that would cause problems under 10 degrees but be fine above?

 

Hard part wear should cause starting problems all of the time.

I wonder if this could be caused by an IAC valve which is not shutting down enough for cold weather operation...

 

That's in the throttle body right? Is it possible to clean without removing the tb(albeit more difficult). I should probably look at the egr valve too...bought a gasket this summer but never got around to it.

 

Yes, the IAC valve is in the throttle body. It can be removed without removing the throttle body, but it can prove to be quite challenging to get the lower bolt (regular torx bit) back in. You will definitely want to magnetize the bit so that the bolt will stay on it.