Someone please help-starting problems

[99ZR2Blazer]

Hope someone can help here is my problem, I have a 1999 blazer with a 4.3. The vehicle starts fine when it is warm outside but when the whether gets cooler(freezing or cooler) then sometimes my vehicle will not start it just keeps turning over and over and if im lucky if i keep cranking it for a while it might start. Got new cap and rotor, new plugs, new fuel filter. Someone said it might be the fuel pump but i got it pressure tested and it was fine. It seems like the cold whether causes the wires to short somewhere or something. This has been going on for a year. Just got through summer and it worked fine now winter and its starting to have problems again. And my friend has the 99 4.3 and he has the same problems. No light comes up-no codes what the hell is this?

[BlazerLT]

So with the new cap and rotor it didn't solve it?

[99ZR2Blazer]

No it didnt solve it. It seems that cold and/or moisture is the problem and it is intermittent so if i do get it to a garage it works fine when i get it there.

[BlazerLT]

I still say it is the fuel pump.

[99ZR2Blazer]

My friend said the pump is at 50 is that too low? Also if it is the fuel pump dont u think it would have died within a year. Also if it is the fuel pump then why does it work fine when it is warm? I appreciate your input.

[BlazerLT]

With key on and not started, you should get 60-66psi on a healthy 1999 fuel pump for your truck.

[99ZR2Blazer]

So this is probably the problem. Does it need more fuel pressure to start in the cold?

[BlazerLT]

Need more pressure period bro.

Make sure your battery up to snuff and fully charged because a low charged battery will result in lower voltage going to the fuel pump which will result in lower pressure.

That is the only way I can relate the cold weather to the no start condition in lesser temperatures.

[Mikado14]

Yep, listen to BlazerLT, that pressure is LOW, not a lot, but enough to give you a problem.

[BlazerLT]

Battery sitting there with nothing started or running should be 12.6+ volts.

14.2-14.4 while idling.

People need to charge their batteries more often for maintanence.

[99ZR2Blazer]

Thanks guys, just talked to the guy who tested it and he said it was 56. He told me that the GM dealership said that over 50 is good enough. Do these guys know what they are talking about? I REALLY appreciate your input.(Damn fuel pumps arnt cheap either)

[BlazerLT]

nope, should be 60-66 cold on without starting.

Check you battery voltage with a multimeter.

[jawill8301]

I have this EXACT same problem!!

I have a 2000 Blazer 4.3 and it will run perfectly fine during the summer months, but as soon as winter gets here it won't start on mornings below 32 degrees. This problem started last year in Jan. and the dealer could not find anything wrong with it when I left it there for a week. Now that its cold its starting to do it again. Did 99ZR2Blazer get his problem fixed? Anyone else know about this?

Thanks in advance

[Mikado14]

Originally Posted by jawill8301

I have this EXACT same problem!!

I have a 2000 Blazer 4.3 and it will run perfectly fine during the summer months, but as soon as winter gets here it won't start on mornings below 32 degrees. This problem started last year in Jan. and the dealer could not find anything wrong with it when I left it there for a week. Now that its cold its starting to do it again. Did 99ZR2Blazer get his problem fixed? Anyone else know about this?

Thanks in advance

Here is one explanation. There is no choke on your vehicle. In order to deliver a richer mixture, the ECM or PCM will deliver a richer mixture of fuel. The colder it is, the more choke required, thus, you need the richer mixture. If the fuel pump is not up to snuff, it will not deliver enough fuel when cold to provide for the richer mixture.

Check the pressure of the pump.