fuel pump, fuel filter, ignition module or other?

ok so i have a 1997 blazer and this past summer i was driving and the check engine light came on and eventually i started losing power as a tryed to accelerate. couldn't gain anything going up the slightest hill and the farther i steped on the accelerator the lower the rpm's would go. the problems corrected themselves the next day. a couple months later the problem came back and left. then last week it came back again and i am fighting it now but am at a loss. check engine light code came back as low voltage bank 1 slot 1 and low voltage bank 2 slo 1. i replaced the O2 sensors, cleared the codes and the problem presists. after reading a bunch of these forums i have come to the conclution that it could be many things i.e. fuel pump, fuel filter, ignition control module, general tune up and fuel pressure regulator. i dont have very much money so i am doing my best at not buying parts unless i know i need them after spending $150 on 2 o2 sensors that didn't fix the problem. i removed the ignition control module to have it tested but apparently this one is NOT TESTABLE! the problem is getting worse by the day. after it warms up i get no power. i drove home yesterday and if i went over 1500 rpm's it would bog down and almost die. thats right 1500 rpm's no typo. this is not going up a hill or anything. flat ground. i'm at a loss please help me figure this out.

Check your fuel pressure. Borrow or buy a gauge (About $40.00).

It should be greater than 60PSI when you turn the key to the "on" position - no start. If less than that, you'll need to check for leak-down at either the pump itself, or on the return line to the tank (pressure regulator).

Let us know if this is the problem, we'll point you to other threads on how to pinpoint the source of pressure leaks.

Where is the schrader valve located?

Where is the schrader valve located?

Behind the throttle body, on the driver's side.

You'll see two steel lines running off the back of the Intake manifold, the valve is on the Feed line from the tank/filter.

In the pic below, it's the black plastic cap on the verticle valve,that protects the threads of the valve.
http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/2.jpg

0 fuel flow at the valve with finger test, relay seems to work alright no fuel flow - sounds like fuel pump?

Is there anything else that would cause no fuel flow?

0 fuel flow at the valve with finger test, relay seems to work alright no fuel flow - sounds like fuel pump?

Is there anything else that would cause no fuel flow?

It's a pressure fitting, putting a finger on the valve won't do much. You need to have the key on (first 3 seconds pump should prime-you should hear it)

Do you hear your pump priming?

If you don't have a pressure gauge, you can always remove a line on the fuel filter. It's under the driver's door, on the inside of the frame rail. Take a line off, and turn the key to "on" You'll know immediately if your pump is working or not.

It would be best to get/borrow a pressure gauge. Screwing it to the valve will release the ball in the pressure valve.

I pushed the valve down with a small screwdriver and I know I pushed it down I have relieved fuel pressure and tested fuel pressure by pushing this valve down with a screwdriver or key several times in the past while holding the valve down someone else turned the key on and off pausing for approximately 3 seconds every time the key was on and not even a trickle coming out of the valve with my ear on the tank I can hear a very faint fuel pump running I will be replacing fuel filter regardless of anything else at that time I will also check and see if there is fuel pressure at the line at that time

Ahh the poor mans method of checking for fuel pressure....if you actually pushed the pintle down and got no fuel out of it, chances are its your fuel pump.

Greetings,
I am helping this gentleman with the problems. We've been posting under one name but I don't know his info, so I created my own.

Anyhow, I did have the pintle pushed down. I am 100% certain of that, the fuel didn't even trickle out there was just enough to wet the end of the screwdriver more or less a puddle inside the valve. The one thing that I am curious of is; I can faintly hear the pump running and that's what makes me a bit concerned that this is not the correct diagnosis. It is possible that there is a blockage and I will be looking into that today. In the off chance that there is some sort of short would the pump be out completely or would it possibly run slower through the short? And please will someone explain to me why if this is the problem did it only happen when the vehicle got warm until finally yesterday it gave up the ghost and decided not to start at all?:banghead:

Thank you very much to everyone for your help it is greatly appreciated.

Greetings,
I am helping this gentleman with the problems. We've been posting under one name but I don't know his info, so I created my own.

Anyhow, I did have the pintle pushed down. I am 100% certain of that, the fuel didn't even trickle out there was just enough to wet the end of the screwdriver more or less a puddle inside the valve. The one thing that I am curious of is; I can faintly hear the pump running and that's what makes me a bit concerned that this is not the correct diagnosis. It is possible that there is a blockage and I will be looking into that today. In the off chance that there is some sort of short would the pump be out completely or would it possibly run slower through the short? And please will someone explain to me why if this is the problem did it only happen when the vehicle got warm until finally yesterday it gave up the ghost and decided not to start at all?:banghead:

Thank you very much to everyone for your help it is greatly appreciated.

Without knowing what the pressure is, this cannot be answered.
A worn pump could produce less pressure as it heats up (overheats), but that's just a guess. A bad pressure regulator would let gas return to the tank without providing the proper pressure required to activate the poppets in the injectors (54psi while running minimum).

Other possibilities could be a bad cam sensor (pick-up coil), bad Ignition control module, bad distributor cap or rotor. All of these can be heat related failures.

update, truck decided to not run this weekend as earlier stated. Replaced fuel filter and now we are back to having a strong spray out the schrader valve so now I will be getting a fuel pressure guage the engine still runs the same after it gets warm. I did pull out the no. 3 o2 sensor to see if it ran better to help eliminate a plugged cat conv, it did not it ran the same. I saw 54psi minimum is this with the engine running? what if it is lower than 54 psi does that mean a bad fuel pump? will fuel pressure indicate a regulator problem?

Check your inbox, full instructions for diagnosing fuel delivery.

54PSI with engine at idle is what mine registers with a new pump.
About 60PSI while driving.
When primed before start, the pump registers 62-64psi.

This gauge should help you determine if it's a fuel pump (~$400.00), or a pressure regulator (~$90.00). The shut off gauge is the lower unit in the pic.

Thanks to write-up Old_master e-mailed me, I made a gauge to check the pump pressure.
http://i43.photobucket.com/albums/e363/Touringmike/car_stuff/gauge.jpg

The gauge was made with parts readily available from Napa and Ace Hardware. Cost ~$27.00.

Napa 730-5013 steel fuel line repair fitting, 3/8"
1 ft 3/8" hose, 2 clamps.
Ace - 3/8" ball valve
3/8" male to barb fitting (for the hose attachment)
3/8" male/female adaptor (because the steel tube hit the ball of the valve)

Old Master's parts were somewhat different, but close to the valve (lower unit in the picture above). I clamped the open end of the hose onto the output of the fuel filter, and steel tube into the pipe to the injectors.
Once the fuel pump primed, I shut the valve as soon as the pump stopped.
Pressure gauge registered 52 psi steadily. As soon as the valve was opened, the gas went back thru the pump, and pressure went to 0 immediately. Leak in the fuel pump was the problem.

update; we took the truck to a shop and after 3 hours the mechanic was left scratching his head. the good news is because they couldnt find the problem they didnt charge us a dime thats a rare commodity. fuel pressure remain good throughout driving and even when the problem existed. computer showed nothing odd believe it or not. The mechanic recommended a thermostat since the truck never ran above 150 degrees we did that today and also pulled the brake booster hose and poured a half can of sea foam into the hose. the truck ran awesome we went to autozone and had the codes cleared (there was a bunch more since we opened a big vacuum port ) but as of right now it seems to be running as good as new, knock on wood. water temp is good as well believe it or not also on a side note when the vacuum hose hit the top of the sea foam can it sucked the can in I was quite surprised.