S10 Blazer Engine Start Issue!?(I Have A Picture!)

I have a 94 S10 Blazer and its always done this since I have bought it, It doesn't start on the first turn, but if you give it a quick crank, than turn ignition off and back on. Than it starts right up and drives great all day. Now over this past weekend on sat and today, it won't start at all. On saturday I just kept trying and it finally gave in and ran great all day and night, Now today it doesn't seem to matter what I do. It seems to starve for gas, as once it gets some gas I hear it want to start.

Anyone here of this? I heard it could be the fuel regulator. I have done a full tuneup except for the fuel filter. I did try to get the fuel filter changed yesterday and the valvoline shop couldn't get it off. I would have done it myself, except when I looked at it, the fittings looked pretty rusted. Also I checked the fuel pressure with a gauge and it was about 53-55PSI at the rail.

Thanks!
Conrad

Alright, So i have been doing my homework and looking online everywhere for this issue. In short I thought I had a bad fuel regulator and pulled the spider plenum and looked in there. the passenger side looked washed out and drivers side was aged with filth. So I took a picture when replacing the regulator. Tell me what you think. I loose fuel pressure over a short course of time. I have in between 53-55 psi everytime i turn the key and while running its perfectly at 55. I heard it could be the fuel pump letting the fuel go back in the tank. It always had a problem starting. I turn the key over, no start, go back and do it again immediatly and it would start. Now it doesn't matter unless i drop a little gas thru the air intake, than it starts immediatly. Please help!! What you think? I really need to take care of this. It also runs great with all power and drives perfect.

Alright, So i have been doing my homework and looking online everywhere for this issue. In short I thought I had a bad fuel regulator and pulled the spider plenum and looked in there. the passenger side looked washed out and drivers side was aged with filth. So I took a picture when replacing the regulator. Tell me what you think. I loose fuel pressure over a short course of time. I have in between 53-55 psi everytime i turn the key and while running its perfectly at 55. I heard it could be the fuel pump letting the fuel go back in the tank. It always had a problem starting. I turn the key over, no start, go back and do it again immediatly and it would start. Now it doesn't matter unless i drop a little gas thru the air intake, than it starts immediatly. Please help!! What you think? I really need to take care of this. It also runs great with all power and drives perfect.

Year and engine code?
You sould have tested for pressure lose before pulling intake and regulator.
Prime up fuel pressure and check for presser lose and watch for pressure leakage before putting cover back and watch the nut kit plastic lines for leakage.

Post back if any leakage in thre now.

For more testing when back together run a full fuel pressure test.

I did check for fuel pressure loss before replacing the fuel regulator. I than realized when i checked that it was loosing pressure slowly and would be at about 40psi after 10-15minutes and so on and so forth. Than when i yanked the plenum intake off, i re pressurized it and could not find any leaks within the plenum visibly. I looked at the nut kit(which is the fuel lines coming in?) and there was no visible cracks or leaks along with everything else that i could see. I put it back together and still had the same issues as before. It wouldn't start no matter what unless i put a little gas in the intake this morning. I did leave a fuel pressure test on it last night and came back this morning and had no pressure on the gauge at all. When i left last night it was at 55psi. So I'm at a loss now and trying to figure this out. I really don't want to yank the fuel pump out and do all that work for nothing if its not the cause. Please help further:banghead::banghead:

What year and engine and engine code?
What is fuel pressure with return line blocked?
How fast is leak off?

53-55psi to way to low. You need to check your fuel pressure to ensure that its not leaking. With the ignition switch on. You should have 61-65 lbs of pressure. Engine running should be 60-66 lbs pressure, pending on the load. Ignition switch off, your pressure should not drop below 55psi within 5 minutes. If it drops below 55psi before 5 minutes. You’ll need to check to see if your injector or Fuel regulator are leaking. If no leaks are found, Then I would replace the fuel pump. Hope this helps.

Its a 94 S10 Blazer with 4.3L V6 Vortec or CPI as they call it. Its not a tbi and the picture above shows that. Also It loses pressure after a few minutes of the ignition be on. I didn't see any leaks visibly when i turned on the ignition and the plenum was off. But the Passenger side looked washed out? Does it not in the picture above? Whats that mean? If fuel regulator, well i replaced that.:confused::confused::confused:

You could have more than one thing going on. The passenger side of the plenum was definitely washed - I think you were right to replace the regulator.

If it's still losing pressure within minutes, I'd suspect the check valve in the fuel pump.

MT can post how you test that (I'm not sure where to pinch off, etc).

Alright, well i think im going to have to replace the fuel pump on it this weekend. Not looking forward to that lol, but eh.. gotta try it! Hopefully it will work, anyone else think of anything that would cause it? Let me know!
Thanks!

Alright, well i think im going to have to replace the fuel pump on it this weekend. Not looking forward to that lol, but eh.. gotta try it! Hopefully it will work, anyone else think of anything that would cause it? Let me know!
Thanks!

Let us know how things come out. I'll be replacing my 97 fuel pump this weekend. Good luck and let us know how things come out.

Alright, well i think im going to have to replace the fuel pump on it this weekend. Not looking forward to that lol, but eh.. gotta try it! Hopefully it will work, anyone else think of anything that would cause it? Let me know!
Thanks!

Proper testing before throwing parts at it.
Would make you more money in your pockets and wiser and go a long way to ward the proper fix..

Well heres what I plan On doing is taking the plenum back off first, but if i can't see any leaks, the passanger side was washed out. What else could it be besides that regulator. The fuel line doesn't hold pressure and over the course of 5 minutes and on it drops dramatically. Is there a way to see if something else is going on? how can i test if the spider assembly isn't holding pressure? will those lines be alright to be moving? or am i gonna be stuck dealing withem if i pullem out to see if there leaking? It just didn't seem that way when i looked in it. (pic is above). What else can i test before checking the fuel pump? I was going to be checking the fuel pump once i get access to it by turning it on and seeing if it drains gas back? Any help would be great.

Well heres what I plan On doing is taking the plenum back off first, but if i can't see any leaks, the passanger side was washed out. What else could it be besides that regulator. The fuel line doesn't hold pressure and over the course of 5 minutes and on it drops dramatically. Is there a way to see if something else is going on? how can i test if the spider assembly isn't holding pressure? will those lines be alright to be moving? or am i gonna be stuck dealing withem if i pullem out to see if there leaking? It just didn't seem that way when i looked in it. (pic is above). What else can i test before checking the fuel pump? I was going to be checking the fuel pump once i get access to it by turning it on and seeing if it drains gas back? Any help would be great.

I would run a pressure test on fuel pump first.
Confirm good running pressure and full pressure with return line pluged.
And check leak down with return line plugged.
Post back your running pressure and full pressure.
When you pull cover off check nut kit in and return lines for leakage to and the pressure regulator.
On injector lines do not move them ans they may be old and brittle and break.

On fuel pump leak back you have to make a shut off valve to shut off the line from the pump before fuel pressure tester.
Or hook a test gauge direct to fuel filter in line and see if pressure drops after pump shut down.
If fump is pumping full pressure pump leak back does not hurt running but may reqiure some extra prime up on start off.

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.
On your engine you should have 55-61 fuel pressure.
Cold start should be 55-61 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 55-61 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 all fuel pressure readings.

Well last night when i got back home I began testing on my truck. I first pinched the return line with a vice grips and found that the fuel gauge showed it was still dropping after about two minutes. So than I looked at the pressure after priming it and it was only 54 also. I know that you must have 55psi for it to start, Well than i looked further by taking the pinch line off and starting it and it ran between 54-55psi. even when i gave her some gas. It usually jumped to 60-61 previously. So i think when i drove it this past weekend, it only got worse and looks like the pump is shot from what i can tell. So last night i made my access door in the trunk as I previously did in my 89 s15 Jimmy. Tonight I will replace the pump and see how it goes. Unless someone thinks otherwise? I would think this is the way to go....

PS. I will take a few pictures of my access door i made so that people can see it. Its way easier than trying to drop a 15 year old cars gas tank which we all know will have bolts that don't want to budge.

53-55psi to way to low. You need to check your fuel pressure to ensure that its not leaking. With the ignition switch on. You should have 61-65 lbs of pressure. Engine running should be 60-66 lbs pressure, pending on the load. Ignition switch off, your pressure should not drop below 55psi within 5 minutes. If it drops below 55psi before 5 minutes. You’ll need to check to see if your injector or Fuel regulator are leaking. If no leaks are found, Then I would replace the fuel pump. Hope this helps.

Those specs are for the CSFI system with the exception of running pressure, GM does not publish any engine running specs, too many variables involved.

The original poster has a 94 CMFI system. Fuel pressure spec for that system, (as MT mentioned) is 55psi to 61psi, and must remain above 50psi for 3 to 5 minutes.

Alright everyone. The results are in. I replaced the fuel pump and it works like a charm. Better than ever actually. Its never started before like it does now.It starts every time on first crank. I had also replaced the fuel regulator which I believed was leaking before and caused hard starts previously till the pump finally gave out and stopped holding pressure. I will post pictures for people to see how i made an access door through the trunk instead of dropping the tank. It holds 56psi with igniton on and runs at about 60psi. Thanks everyone and hope everyone had a great weekend!