please help no start fuel injectors not getting fuel

[pjftmd107]

I have 95 blazer that will start with starting fluid but wont stay running. The truck has been sitting for four years the fuel lines are all new the fuel pressure is 55 psi at the pressure valve behind the the intake i know the injector spider thing in the intake has been replaced and does not have 5000 miles on it. i have checked all the fuses and even replaced the relays in the glove box( i know that was not necessary because of i am getting fuel pressure and can hear the pump working and see the gas flowing through the pressure valve checker. Please help

[Airjer_]

I wonder if the poppets have froze. It doesn't take much to pull the plenum off and pull a couple of the poppet valves out of the lower intake to see if there spitting fuel.

Something that would be a lot easier is checking the injectors with an injector tester. You could do that without pulling the intake. Basically it is a little tool that hooks up to one injector at a time and then fires that injector however many times you set it to. If fuel pressure drops than the injector is working if the pressure doesn't drop than you can dig in a little deeper.

Checking for injector pulse and power to the injectors may not be a bad idea either.

[MT-2500]

95 4.3 code W engine 55 pressure is low for a cold start.

You need 60 for a cold start to squirt injectors.

Check full direct fuel pump pressure at fuel filter or with return line blocked.
If you do not have 75-90 lbs full pressure your fuel pump is weak.

On injectors check for 12 volt power to them to start with.

Post back what you find.

[pjftmd107]

Thank you everyone for all the help just got out of work and about to get under the hood again

[bozr]

Never had much luck starting engines with 4 year old gas, if that's how old it is.
It will run if the cylinders are warm, just not fire off cold.
Try putting some fresh fuel in, purge the fuel line and try starting it off carb cleaner for a minute or two.
You may also have some water in the tank and that settles to the bottom.

[pjftmd107]

I want to thank all for there advise it turns out the main injector for the injector rail was froze up tarnished from the old gas sitting there the shop let the injector rail sit over night in carb cleaner and put it back together it runs great once its warmed up the fuel pressure bothers me some so i am going to buy a new pump. any suggestions on who makes the best autozone has the cheapest but I'm not to sure how reliable it is

[MT-2500]

Originally Posted by pjftmd107

I want to thank all for there advise it turns out the main injector for the injector rail was froze up tarnished from the old gas sitting there the shop let the injector rail sit over night in carb cleaner and put it back together it runs great once its warmed up the fuel pressure bothers me some so i am going to buy a new pump. any suggestions on who makes the best autozone has the cheapest but I'm not to sure how reliable it is

You are welcome.
Cheapest is not always the best.
The only good pump is the AC-Delco/Delphi fuel pump.
They will try to sell you a AIRTEX junk fuel pump.
Say now way.

Ask them for the delphi pump even if they have to order it and only 25$ more.

But check out the pump before throwing parts at it.

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 or hot and fuel pressure testing guide lines.
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.