tps checked out fine. Decided to do a voltage check on the map sensor i just replaced a week ago and there was the problem. Returned the sensor for a new one and the blazer started right up. Tomorrow will be the final check, after it sits all night . Thanks everybody for their help!!

 

Glad you found your problem. Good job!

 

i got the same issue. wont start when cold. runs great when hot.. i seem to be getting a fuel cut off or something on cold starts. i have changed a lot with no results.

new parts:
ing mod, coil, wires, plugs, cap, dist, rotor, 2 new o2 sens, new fuel lines to spider assm. new coolant temp sens,

egr has been cleaned, the intake gaskets upper and lower are brand new.

fuel pressure at 62 and holds it during idle, goes up during acceleration to 68psi
no check engine lights
im pretty smart but this is got me dumbfounded.

a few threads say fuel pump, but it is in range and works great. i was thinking o2 cause the heater was bad in one of them. but nothing happened.

im about to burn this pos to the ground.... grrrrrr.. on it. lol

Thank you for all of your help guys.

well off to the junk yard today to get a map sens. it worked for u lets c if it will work for me.

good job jm01gt....

So did it start up this morning?

 

well that didnt work for me

 

If you have a fuel pressure gauge hook it up in the evening before you park for the night. See if you still have pressure in the lines in the morning. My Blazer had the same symptoms and it was the check valve in the fuel pump bleeding back. I had to replace the fuel pump (one complete unit) and that solved the problem. The pump is a real pain to replace it's in the tank.

 

sorry i didn't get back to you sooner, computer crashed. it is going to be the fuel pump. map sensor only worked for about a week. Beware, these fuel pumps are not cheap. There is also a screen at the bottom of the funnel so you can't siphon the gas. had to let it run almost a whole day to use up the gas in it. That was about a month ago and since then i have had no problems. Hope this helps!

 

I had a similar problem with my 2000. everything I checked was ok. including fuel pressure. Like you, I couldn't find a problem. If I got it going in the morning, it would usually be ok for the day. When it was colder it got worse. One day after work, it wouldn't stay running for anything. Towed to shop. They called and said Low fuel pressure. I couldn't believe it. I went and checked with my gauge. they put fuel pump in and ran better than it ever did since I had it. Not saying thats the problem, but I sympathise with you.

 

I know this thread is old, but I am in the exact same boat right now.
Takes about 50 cranks or so to get it going then runs great all day, next morning same deal.
but this is after i changed the fuel pressure sensor. before it would pretty much start right up.
the fuel pressure sensor is not leaking no more.
I change the plugs, wires, rotar, rotar cap, fuel pressure sensor. and oil change of course.

I was told tonight to change the Temp sensor, but which one lol.

i guess i can try those then last i guess try the dang fuel pump. it works great.
when i put the key to the ON position without starting it does the fuel pump supposed to go on then shut off on its own or stay on as long as the key is in the ON position.

 

The pump should only run for a second or two, then stop.

 

If you have a fuel pressure guage hook it up. it must read 61 - 65 lbs. mine read 58 and i thought it was close enough. But it's not. after changing everything else i finally changed the fuel pump and it's been running great ever since. beware the fuel pumps not cheap. Picked it up at advance for $230. hope this helps. Found out later blazer's are known for this problem.