'99 Blazer need serious help

[Riftcloud]

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.

[riccbhard]

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.

[Riftcloud]

Originally Posted by riccbhard

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.

[riccbhard]

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.

[Riftcloud]

Originally Posted by riccbhard

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?

[Gabe25]

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.

[Riftcloud]

Originally Posted by Gabe25

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.

[Riftcloud]

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

[Gabe25]

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

[riccbhard]

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)

[Gabe25]

Originally Posted by riccbhard

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?

[Riftcloud]

Originally Posted by Gabe25

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

[Riftcloud]

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.

[Gabe25]

Originally Posted by Riftcloud

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/vbul...&highlight=cpi

[BlazerLT]

Originally Posted by Gabe25

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

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