'99 Blazer need serious help

I need help with my '99 blazer V6 4.3L vortec. I was driving down the interstate the other night when my engine started chugging when I would push on the gas. This happened a few times and then my engine just died. I got it home with a tow truck, and a friend has helped me work on it. We've changed the fuel filter, checked to see if pressure is coming from the fuel pump, and it is. We changed the spark plugs, and now the engine is still acting the same. If we can get it to start, it idles just fine, but when I push on the accelerator, it starts chugging and acting horrible, and if I don't let off the gas it dies. After a while at idle it starts dying on us again. Any help would be appreciated.

Is the fuel pump running normally?

How about the spark plug wires and distributor rotor/cap?

Just to check; although it may not cause the problems you're having, check what the voltage is at the battery when the engine is running.

Should be around 14 volts and will fluctuate a little with engine RPM. Sometimes electrical issues can cause certain running problems.

Is the fuel pump running normally?

How about the spark plug wires and distributor rotor/cap?

Just to check; although it may not cause the problems you're having, check what the voltage is at the battery when the engine is running.

Should be around 14 volts and will fluctuate a little with engine RPM. Sometimes electrical issues can cause certain running problems.

Yes the plugs have good spark, and yes it appears that the fuel pump is working properly. Battery and alternator are strong as well. It seems as if the engine is having trouble with air or fuel, but like I said the fuel side seems good.

I'm not so sure when it gets down to the engine; but you may want to check if the injectors are firing; and check for any leaks in vaccuum hoses.

I'm not so sure when it gets down to the engine; but you may want to check if the injectors are firing; and check for any leaks in vaccuum hoses.
What do you know about the MAF sensor?

Check your fuel pressure at the sharder valve. You should have 60 - 65 psi with the ignition switch on. If youdo have the right pressure. Open your Plenum and check for fuel inside and let us know what you find.

Check your fuel pressure at the sharder valve. You should have 60 - 65 psi with the ignition switch on. If youdo have the right pressure. Open your Plenum and check for fuel inside and let us know what you find.
I'm at work right now, and we have limited time tommorrow to find the problem, so I'm trying to get a gameplan of all I can check when we hit it tommorrow.

another thing we did was put dry gas in and a few gallons of good gas thinking that it might have been a water in gas problem

Check your Fuel Pressure, CPI & Nut Kit for Leaks. That sound like the ticket.

How about the MAP (Manifold Abosolute Pressure) sensor? This little thing has caused major idle problems in our 89 Camaro 305. However the one for the Blazer I think is more expensive.

The MAP sensor for our '98 Blazer V6 Vortec is $49.88 at Advance Auto Parts. The one for the '89 Camaro is $30. They're both GP Sorensen.

If you do suspect the MAP sensor first check the hose from the sensor to the manifold and look for any leaks and make sure it's not loose. And also check the electrical connector to the sensor.

(Yes; I know you said MAF, but the MAP can also cause similar problems I've found)

How about the MAP (Manifold Abosolute Pressure) sensor? This little thing has caused major idle problems in our 89 Camaro 305. However the one for the Blazer I think is more expensive.

The MAP sensor for our '98 Blazer V6 Vortec is $49.88 at Advance Auto Parts. The one for the '89 Camaro is $30. They're both GP Sorensen.
Before you start changing things out. You need to know what your fuel pressure is first. That will say alot. Do you have any error codes?

Before you start changing things out. You need to know what your fuel pressure is first. That will say alot. Do you have any error codes?
My check engine light is not coming on with this problem so I'm thinking there aren't any codes

Tell me if I'm wrong but I'm thinking that the fuel pump either works or it doesn't. I don't understand how the pressure could be low.

My check engine light is not coming on with this problem so I'm thinking there aren't any codes
OK, You can pull you MAP sensor and just clean it. Brake lean is what I use. Then reinstall it and see if that work's. If not, You need that fuel pressure reading. If your pressure is low then more then likely you need to replace your pump. You'll need to open the Plenum and check for fuel washing inside. If there is fuel inside. You'll need to replace your CPI and Nut Kit. Good luck in locating the trouble. Here is a link that can help you with the CPI.
http://www.automotiveforums.com/vbulletin/showthread.php?t=473110&highlight=cpi

Check your Fuel Pressure, CPI & Nut Kit for Leaks. That sound like the ticket.

Gabe, his is a 99, not a 92-95.

a friend here at work is swearing by the PCV valve what do you guys think?

MAF sensor.

PCV valve will nopt cause driving problems, only idling problems.

Sounds pretty serious for it to be a MAF though, and it's idling fine... I'd think it'd be idling erratic if it were the MAF. Not that it isn't worth your while to check, as it's very easy to do so, just think you need to consider other possibilities is all. Give it a clean with a soft toothbrush and some brake cleaner like LT suggested.

For what it's worth it DOES sound like you're getting too much gas and not enough air. Check your throttle position sensor maybe?

To cuase such a massive driveability, he is having problem with one of these things.

1.) Fuel pump
2.) MAF Sensor
3.) Coil

Also, when has a tuneup been done lately?

the motor is fairly new only 50k miles. when I replaced the motor I changed plugs, wires, hoses, just about all accessories. Today I changed the plugs again. The old plugs were fouled and soaked with fuel

Ever change the cap and rotor?

that was changed when we changed the motor 50k miles ago

Well, you are due for a tuneup

50k is when this all should be done.

well I'm getting there. Like i said before, really the only thing left for me to change for a tune up is the cap and wires. I am getting good spark though which brings me back to my big problem. engine running rough and no power. (can't drive it)