2001 blazer

[crazyman896]

i had changed the fuel filter on my blazer when i went to start it all it does is turn over it wont start the fuel pump is pumping fuel

[MT-2500]

Welcome to AF.
Get a fuel pressure gauge on it and post back fuel pressure readings.

What engine and mileage and service history and more info would help us help you.

[crazyman896]

Originally Posted by MT-2500

Welcome to AF.
Get a fuel pressure gauge on it and post back fuel pressure readings.

What engine and mileage and service history and more info would help us help you.

4.3 engine with 200584 miles it ran fine till i changed the fuel fitler it trys to start sometimes it will run for a min or so real rough the shuts off with it backfiring through the carb i have no way to get a fuel pressure gauge

[MT-2500]

Was the old filter stopped up?
With rust or water or black stuff.
Got gas in the tank?
Fuel pressure needs check out to start with.
Borrow /rent or buy a pressure gauge.
Some parts places loan gauges.

Post back fuel pressure readings.

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold and fuel pressure testing guide line.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

[crazyman896]

Originally Posted by MT-2500

Was the old filter stopped up?
With rust or water or black stuff.
Got gas in the tank?
Fuel pressure needs check out to start with.
Borrow /rent or buy a pressure gauge.
Some parts places loan gauges.

Post back fuel pressure readings.

The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold and fuel pressure testing guide line.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

ty for your help but problem is fixed now running fine again

[MT-2500]

You are welcome.
But how about.
Let everyone know what the problem was.

[crazyman896]

Originally Posted by MT-2500

You are welcome.
But how about.
Let everyone know what the problem was.

I just let it sit over night went out next morning an it started right up guess it just wanted to be stuburn or something. I dont know but i do have another ? about this vehicle it has the P0507 code IAC high rpms.The engine idles at 1000 rpms and when i put it in gear the rpms drop to 800 rpms.When im driving an let off the gas it slows down an rpms drop like it should.I have replaced a few parts on this vehicle such as o2 sensors, MAS sensor and done regular maintinace on it such as changing oil,plugs,fuel filter,only thing different i did was put a K & N air filter in it

[MT-2500]

Run the fuel pressure test and post back readings and we can help.