Cold temp. starting issue - Page 2

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

quote:

ORIGINAL: swartlkk

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...

quote:

ORIGINAL: swartlkk

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.

quote:

ORIGINAL: swartlkk

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.

 
Thanks... i might just take the tb off... i had it off my 3.8 enough times i should be able to manage.
 
 

Just be careful with the little plastic clip on the cruise cable.

Okay... i plugged in the block heater last night and this morning it fired up like it was 30 deg in the middle of summer!  That confirms my temp suspicion.  So my question... what does the block heater heat up... the temp guage inside read warm so i imagine the coolant and thus ect reads warmer... would the iat read warmer too?

I was having the same issues, replaced everything including battery.  Seemed like electrics was the issue because when I left the charger on it or jumped it with another vehicle it would start.  Found the following page, check the symptoms section:
http://www.2carpros.com/forum/1996-chevy-blazerfuel-pump-replacement-vt174360.html
 
Those were my exact symptoms.  Did the fuel pump and tank job yesterday and fired up first time this morning after sitting all night.
 
 

quote:

ORIGINAL: scorpdad

I was having the same issues, replaced everything including battery.  Seemed like electrics was the issue because when I left the charger on it or jumped it with another vehicle it would start.  Found the following page, check the symptoms section:
http://www.2carpros.com/forum/1996-chevy-blazerfuel-pump-replacement-vt174360.html

Those were my exact symptoms.  Did the fuel pump and tank job yesterday and fired up first time this morning after sitting all night.

 
Those aren''t quite my exact symptoms.  I have 60psi and it holds during the cold start problem.    Was your pressure good or a bit low?
 
UPdate: (forgive my explanation), but my initial timing was -8deg so i had the dist hold down ground so the dist could be adjusted.  It''s now -1 and the correct re-learning was done.  Unfortunately this didn''t help my startup problem.  We also checked out the IAC valve... he could open and close it with the scanner..and on a cold morning when it was acting up I held the pedal at various positions to no effect.  The only thing that works is the block heater.

Have you ran any injector cleaner through this truck?  Overdose it to really get a good cleaning action.  I would use two 20gallon treatments of Chevron Techron Fuel Injector Cleaner Plus.  The reason why I say this now is that I experienced a very similar thing with my parents car when we parked it outside one night when it was below zero (-15*F) without the windchill and the wind was howling.  Ended up that the injectors were sticking due to the cold.  We solved it with a simple drop light (60w bulb) placed on top of the engine with a blanket over it.  Ran some injector cleaner through it and the problem went away.

Food for thought.  These injectors used in these engines are known for buildup.

quote:

ORIGINAL: swartlkk

Have you ran any injector cleaner through this truck?  Overdose it to really get a good cleaning action.  I would use two 20gallon treatments of Chevron Techron Fuel Injector Cleaner Plus.  The reason why I say this now is that I experienced a very similar thing with my parents car when we parked it outside one night when it was below zero (-15*F) without the windchill and the wind was howling.  Ended up that the injectors were sticking due to the cold.  We solved it with a simple drop light (60w bulb) placed on top of the engine with a blanket over it.  Ran some injector cleaner through it and the problem went away.

Food for thought.  These injectors used in these engines are known for buildup.

 
I have run a bottle of Lucas Fuel injector cleaner through it... but it''s a small bottle :)  Not sure how available the chevron with techron is in canada??  I can try to overdose it. 
 
I''m not 100% clear on your fix for your parents car...you used the drop light once and then with the  cleaner the problem went away?
 
To tie this to my block heater angle... would running the block heater overnight heat up the injectors a bit?  If they would be heated up then i can see this as a possibility.

Keep in mind also that the outside temp only need be 5degrees above celcius(at time of startup attempt) for the cold starting problem to occur... sub zero temps are not necessary.

On my parents car, the heat of the drop light was enough to warm the injectors, allowing them to properly open and close. 

Your problem sounds eerily similar which is why I brought that up.  Yours just may be that they are gummed up to the point where even 5*C temps cause them to not want to open.  You have to remember, you need to open two valves with the fuel injection system on these trucks.  #1 is the electronic injector.  #2 is the pressure actuated poppet nozzle on the other end of the tube, fixed into a bore on the lower intake manifold.

Alright, i''ll give that a shot... assuming I cannot find the chevron ... are there other brands that are better or worse than others?  Or should I be able to get the chevron in southern ontario?

I would hope you could find Chevron...  GM has their branded cleaner that will work just as good (I think it is Chevron made anyway).

quote:

ORIGINAL: swartlkk

I would hope you could find Chevron...  GM has their branded cleaner that will work just as good (I think it is Chevron made anyway).

Alright thanks.  Were you eventually able to start your parents car...would it eventually fire?  Mine has never failed to start... typically around 5 degrees it will take about 3-5 times to fire, and sub zero temps 8+ but it has always eventually started.
 
EDIT:  I just filled up the tank yesterday..should i wait until it''s lower in fuel to increase the cleaner to fuel ratio or just dump 2 or 3 bottles in the full tank?

We drained the battery trying to get it to fire.  It would start instantly on starter fluid, but then die.  20 minutes with the light under the hood and the charger on the battery and it started right up.

I would wait until you can dump in 5 or so gallons of fuel with it to mix it appropriately, especially with a concentrated dose.

quote:

ORIGINAL: swartlkk

I would wait until you can dump in 5 or so gallons of fuel with it to mix it appropriately, especially with a concentrated dose.

 
You mean it''s more important to have fuel go down after the chevron to mix it up than the ratio of fuel to chevron?  Just making sure i understand :) 
 
Should I try starter fluid as a test in the meantime?  You spray that right into the tb correct?
 

You could try starter fluid, just spray it into the throttle body, then reattach the intake duct (or disconnect the MAF sensor).  If you try to start it with the MAF sensor connected, but air not being pulled through it, it will die. 

And yes, drive it around a bit to lower the level in the tank.  Dump two 20gallon treatment bottles in and then fill it up.  This will mix it up appropriately.

Alright, i''ll try the starter fluid this week and later in the week when my tank is around half i''ll add the cleaner.  Thanks!

UPdate:  I had a zero morning this morning, 3" of snow overnight...finally a cold day where the truck wouldn''t fire up.  I sprayed liberally the throttle blades of the tb with starter fluid and attempted to start the truck with the throttle part open... fired up right away!

So this confirms i''m not getting fuel to the combustion chambers correct?(since it''s 60psi at the rail).

Anything other than injectors that could be ''sticking'' or otherwise misbehaving in cold weather for starting?  The ''spider''? 

I''ve got my fuel injector cleaner(2 bottles) and will put them in later today when i''m closer to empty and fill up.  Ih ope it''s just sticking injectors and this fixes it but is there anything else that could be now that we know starter fluid works?

So how much of the cleaner/tank would you expect might need to go through the system to clean this up assuming it will work?  It''s now -3 deg out and it only takes a few hours for the truck to cool down enough where i need the starter fluid to get it going again....which means i''m going to be using it everyday when i leave work :(    I''ve driven to about 3/4 tank after putting in the 2 bottles of cleaner.

It may take two tanks like that.  Then again, it may just not work period resulting in the only foreseeable solution being to replace the spider.  That is of course if the injectors are the true problem.

quote:

ORIGINAL: swartlkk

It may take two tanks like that.  Then again, it may just not work period resulting in the only foreseeable solution being to replace the spider.  That is of course if the injectors are the true problem.

 
Would a scanner that monitors injector duty cycle help determine if they''re not flowing properly?  The problem of course is i need either the block heater or starting fluid to get the engine to fire...which would be when it could be scanned.    I''m pricing out the MFI spider now, just to know what to expect.
 
I dont'' mind plugging in at night to get an easy start in the mornings...but this starter fluid after work thing will get old soon :(

I hate recommending things as drastic as replacing the spider without running through the testing.  The bad part is, without taking the truck out of commission for good while, it is very difficult to test my theory.

I was able to get the spider from my local dealer for just under $300 out the door (IIRC).  If you have an AC Delco retailer close, it keeps the dealers more honest.  I have listed the part number somewhere around here.