I just had my fuel pump changed in my 97 blazer LT. 125000 miles. It was driving fine for about 2 hours then it started acting like it was starving for gas and started to stall from take off and each time after that. I didnt turn it off until I got home, but before I turned it off I gave it some gas and it hesitated. It sounds like it wants to start but isn't getting the gas. I've checked and listen for the fuel pump and can hear it whinning. I did however notice that the other day my daytime lights didn't come on until the second time I started it. No codes are being thrown now. At first I had a o2 sensor code but that went away. So now it sits and waits. Suggestions????[&o]

 

When you changed the pump, did you change the filter as well?

Have you tested the fuel pressure at the schrader valve on the fuel feed line (larger line on the driver's side of the intake)?

 

Yes. Filter was changed as well and fuel pressure checked at schrader valve. Mystery huh?

 

What was the fuel pressure when you checked it?

Did you try swapping the fuel pump relay with another, known to be good, relay?

Have you tested the ground at the pump? There have been some instances of harness/connector damage during the pump replacement procedure... This may be another case...

 

I have not switched relays yet. If the relay was bad would the the pump still whine? The pressure was over 60 that I remember.

 

Ok... It sounded like you were trying to say that you weren't getting fuel, hence my responses. Now I see that you do have the proper pressure.

So from there, have you verified spark? Can you get it to start/run with starting fluid?

 

Yes. there is a spark. Haven't tried starter fluid yet. How would that help in the long run? Just curious. This all new to me. Great post from all you guys!!

 

I am just trying to get a handle on what's going on with your truck. Basically, the questions I have asked are the steps I would go through if the vehicle were in front of me.

Starter fluid wouldn't help anything in the long run, but it would validate the presence of air and spark. If it starts on starter fluid (or gas down the TB with the MAF sensor unplugged), then there is something keeping the injectors from firing.

 

Oh!!!! Okay. Sorry for sounding so dumb. I will try the starter fluid when I get home and post results.

 

No, don't be sorry. You didn't come across that way at all. It is definitely a different experience to get bombarded by questions right after asking one. LOL.

I'm just trying to gather information to help myself and anyone else with insight into your situation help you figure it out!