Hey all, noob here,

I have a '99 s10 blazer, 4 door, 4wd, LT package.

The other day, just as I was starting up a hill, the engine died.

Just under a quarter tank of gas left, all electrics were working.

Got it home and checked possible issues. Added more fuel to the tank in case my fuel guage wasn't reading properly. Now registers just over half a tank and the fuel guage has always been spot on for me.

Fuel pump sounds like it is working and makes the proper noise and I have spark on the spark plugs. Matter of fact, in testing for spark, my buddy got shocked even though he wasn't touching ANY metal when testing for spark. I was under the impression that the rubber around the spark plug wires would prevent this. It did not.

But, no matter what, it isn't starting. The starter works fine and it is turning over just fine, but it isn't catching. Not even a slight cough. The engine just turns and turns.

After running the battery down, I hooked up the jumper cables and tried everything again, but had a friend around back. He said he could smell a very slight scent of fuel as I was turning over the engine and pumping the gas. I was thinking that if I was pumping the gas pedal, there should have been a stronger gas smell. (I was only pumping the gas like that to see if I was getting gas through the system, not because I think that's how I should start the truck)

Is there a chance that the fuel filter is simply clogged, or could there be another explination? Is it possible for the fuel pump to make the right sound, but not be actually pumping fuel to the engine? Or could it be an issue with the fuel injection system. If so, how would I find that out?

Any help is MUCH appreciated!

Thanks!

 

Go ahead and change the fuel filter if it hasn't been done within the last 30,000 miles. Also do a fuel pressure test. I've outlined the method several times, use the 'search' function to find one of the posts. Let us know what you find.

 

I'll second the fuel pressure test. It is easy to smoke a pump and if you were below 1/4 tank as well as going up a steep hill, it is quite possible that you have overheated the pump.

I would do a pressure test first, then replace the filter after you have determined if the pump is still good or not. If the pump isn't good, then I would wait to change the filter until after you have replaced the pump.

 

First off, thanks to all who read and offered advice.

To begin with, I followed the advice and purchased a fuel pressure guage.

After attaching, it read a mere 14 psi.

As a hopefull quick fix. I replaced the fuel filter. At one point after the old filter had been removed, we placed a pan underneath and quickly turned the key to where the fuel pump would turn on. Gas shot out of the line, so I thought that the pump might be fine.

We quickly installed the new filter, and rehooked up the jumper cables (we'd run the battery down trying other things earlier). After the new filter, the pressure only went up to 29 psi.....:-/

So, the new question is if there is any other equipment or things that could cause a blockage in the fuel line between the filter and where the pressure guage attached, or, is it possible fora dyingpump to have enough pressure to get some fuel flowing, but not enough for the FI system to get it into the engine? Or do fuel pumps just flat out die?

I'm a vehicle mechanic noob, and know diddly about FI systems, so please bear with me.

If it is the pump, other then the expense, it will be a relitivly easy fix, so i'm not so worried about that. My real worry now is that it might be the FI system.

Thanks again to all.

 

A pump can go out gradually or suddenly. You need ~51psi to start the engine, and you have just over half that amount, so it appears that you have a bad fuel pump. When you replace it, do yourself a favor and use AC/Delco. Using aftermarket pumps in these trucks can be sketchy.

 

If you are concerned about a blockage, then you should attempt to connect the fuel pressure gauge at the fuel filter location (the line the gas shot out of when the fuel filter was out). You will need to adapt from the gauge thread (CLICK HERE) to the fuel line connection (1/4" or 3/8" compression fitting??? - can't remember exactly). If you test here, you will remove the rest of the fuel system from the equation and should see in excess of 60psi with a good working pump.

 

Ok,

After following all the advice given here, I purchased a new fuel pump and yesterday my buddy and I installed it. While a learning experience, it went VERY well, and much easier then we expected.

I found corrosion on the fuel pump locking ring, cleaned it off and oiled it.

We drained all the fuel from the tank and I cleaned the inside as best I could as well. Got a fair amount of residue out as well as some larger bits that fell in when I removed the old filter.

I filtered all the gas that I removed using coffee filters and reused it when done. The coffee filters clogged very quickly, so there was a bit of gunk simply floating in the gas in the tank.

On all rubber seal rings, I used a light coating of oil to ensure a good seal, just like when you install a new oil filter. I scrubbed and cleaned the O-ring lip on the fuel tank as well to ensure a good seal as well. I took no chances with having a leak in the system.

After completing the reinstallation, we put the fuel back in and tried starting.

Nothing happened. Couldn't hear the fuel pump at all.

After making sure the connections were in place properly, still nothing.

As I had my buddy back by the fuel cap listening for the pump as I was turning the key to just before start then off again, then on again, etc, to see if we could hear the pump, I accidentally turned it over to start and lo and behold, the damn thing started up!

Turns out that it was easy to hear the old, dying pump because it was just noisy as hell, but the new pump was very quiet and VERY hard to hear, but it works fine.

With the new filter and pump, my gas milage has increased by about 30% as well, and the truck idles very smoothly and evenly. Much better then it has for some time. Every so often, when I stop somewhere, I check the ground and the tank for leaks, and so far it's holding up perfectly.

So, after being successful in dropping a half full tank, emptying it, removing a broken pump, cleaning the tank, installing a new pump, reinstalling the tank, busting knuckles, knocking my head, going loopy from the gas vapors, all with absolutly no background in auto mechanics, and getting my truck working, I re-attached the fuel preassure guage and it didn't register a thing. The damn thing is busted.....:-/

Oh well, it was 40 bucks wasted, but the truck works and it works better then before, so I don't mind. Better that then spending 800 to 1000 dollars for an auto shop to fix the fuel pump issue.

Thanks to all who provided advice and guidance. You've been a great help!

 

Congratulations on the repair! Hope it permanently solves the problem. Do yourself a favor and get in the habit of not letting the tank get below 1/4 full and about every other oil change run a bottle of Techron Concentrate Plus in the gas tank.

 

Glad you got it fixed!!