hard starting when cold outside

[bigcrunch]

1996 V8 when engine is warm and below 32f outside go to start it most of the time it will not.
If I ether it it will most of the time.

When engine cold and below 32f outside starts but have to try about 5 times.

no check engine light on, no codes. Did this last year was a weak battery, replaced it and checks good.

any ideas???

 

[Big Z]

So, WITH the engine warm it won't start back up?

You might could start simple in a tune-up manner and run fuel injector cleaner and heet, new spark plugs, etc

 

[1AJeremyD]

Change fuel filter and go from there. Pump could be getting weak in its old age

 

[synyster]

did you check the condition of the battery? fully charged? The fuel pump is an option. Mine's on its way out and its only an 02.....

 

[bigcrunch]

battery charged had it load tested, less than a 1 year old.
pump is about 2 years old with new filter. I can hear it kick on when I turn key.just no start when below 32f and engine warmed up. I only get gasoline at newer stations.

real strange. I'd like to keep my first gen V8 running been a good vehicle!

 

[bigcrunch]

Had a thought, replace the fuel pump relay it has almost 300,000 miles of use on it. Anyone know where it is?

It could be cutting off once starter engages.

 

[OneLever]

pump is about 2 years old with new filter

What brand fuel pump did you use? A few of the aftermarket ones are notorious for failing.

 

[bigcrunch]

What brand fuel pump did you use? A few of the aftermarket ones are notorious for failing.

from Advance

 

[OneLever]

Advance Auto Parts sells Airtex and Bosch fuel pumps. If you do a forum search for Airtex fuel pump's you'll see people have had issues with them. Do you know which brand you bought?

 

[bigcrunch]

probably airtex

 

[bigcrunch]

I found the original box it is airtex.

any experience with AC delco or Delphi pumps??

 

[OneLever]

None from personal experience but this thread from the forum search gave some suggestions.

 

[bigcrunch]

Update I replaced the pump with a Bosch 67000 from rockauto.com very good price compared to regular parts outlets.
It took me a little over 2 hours to complete(I'll give some hints to help at the bottom) what was in there was a Airtex brand pump the plastic casing was starting to warp at the top where it snaps together.
It was 2 years old and I have a therory why it would start on ether when cold then run normal until shutdown again. I think when the Airtex components where exposed to below freezing temps not necessarly frozen the components internally to the pump would deform ever so slightly that the 12.5 volts in the battery where not enough to get it moving once running(on ether) the alternator puts out 14.4 volts which I think would get the pump pumping.

With the Bosch it started on the second try, it had to fill the lines and I can hear the pump quite noticably once I turn the key before starting. The Bosch has made on the USA on it comared to the Airtex made in China.
Only issue I see now is looses pressure in about 2 minutes. It maybe injectors since I replaced the pressure regulator previously.

some procedures I used to ease removal and install off gas tank:

-raise vehicle at all 4 corners on jack stands.
-remove spare tire makes it easier to get to lines.
-use jack to lower and raise tank.
-have a skilled assistant available.

 

[OneLever]

I'm glad the forum helps steer us away from products that are of poor quality. Thank you for updating us and helping future readers pick a better pump. So does it run well now?

 

[bigcrunch]

It starts in the first try now at 40f outside, I am hoping for below 32f weather to try it before I drive it to work and far from home jsut to get a comfort feel.

The pressure loss while sitting I want to address next I feel it must be injectors they have almost 300k on them but I'd like to find a shop in the Atlanta-Athens Georgia area that has a test machine that can plug in individual injectors into and check the spray and leak down. At $60 each I don't want to replace them blindly.
Anyone know of such shop please share.

 

[OneLever]

1. What is the pressure when the pump primes before the engine starts, when the engine first starts, and then what does it drop down to?

2. Does it continue to run after the pressure drop?

3. You think the injectors are sticking open and causing a loss of pressure?

 

[bigcrunch]

1. What is the pressure when the pump primes before the engine starts, when the engine first starts, and then what does it drop down to?

2. Does it continue to run after the pressure drop?

3. You think the injectors are sticking open and causing a loss of pressure?

1. 30+ psi
2. pressure drops only aftrer I shut off engine
3. I suspect injectors hence I'd like them checked off the vehicle. Pump, filter and pressure regulator ahve ben replaced.

 

[OneLever]

2. pressure drops only aftrer I shut off engine

Engine off, key in the ignition?

What does it drop to?

 

[bigcrunch]

Engine off, key in the ignition?

What does it drop to?

Engine off, key in the ignition. Yes

What does it drop to? zero psi