I borrowed a fuel pressure gauge from O'Reillys.

1st cycle of key the fuel pressure went to 5psi.

2nd cycle- 15 psi

3rd cycle- 30psi

4th cycle- 50psi

5 cycle- 60psi.


Could this be a plugged fuel filter?

 

I did put a new gasket on the plenum. When I looked in the plenum for the most part it was black except in the back on the driver side it looked goldish silver...almost clean.

 

Actually after taking the carb. Back off it looks like maybe number 1port inside the plenum is goldish in color. Not all black with carbon like the other ones. Not clean by any means but clean enough to see a goldfish color.

 

holdddddd up. It may be a dirty maf sensor. (the sensor between the air tubing and the breather cap. (the big silver square thing)

grab a can of maf cleaner. DO NOT buy brake,carb,throttle body cleaner. there is a difference. pull the maf,spray it liberally. especially the lil rice sized pin in it. let it dry for a few min. throw it back in and start it. those mafs rarely go bad. they get dirty. they can cause some crazy **** to happen.

 

doubt it. u could try,but sounds like weak pump. your a regular. you should know about the pos cheap pumps. u better buy ac delco or il smack you lol.

 

Thanks. I'll give it a try. I have nothing else to lose. I'm scratching my head quite a bit now. Hair is flying. :-)

 

If I do have to change it I will definitely use AC Delco. No smacking needed here.:-) but I think I've ruled out the pump now and I appreciate your advice. I think I was troubleshooting faster than I was keeping up on here. I got 84psi at the fuel filter and it held 65 psi for 10 minutes...or something like that. Then after connecting back up top I got 60 psi and it held...some psi:-P I don't remember now. I think I posted the number earlier but anyway I think I'm back to the plenum area again troubleshooting. I think the pump is ok now plus after I put the breather back on the carb. It ran fine. Even though the plastic breather housing that sits on top of the carb. isnt mated up to the flex tube that comes from the air filter. So I still don't know what the deal is but I appreciate you all brainstorming and sharing your knowledge.

 

Maximum pump output pressure of 84psi is within specs, and holding 65psi, means the pump is fine. Regulated pressure at 60psi is at the lowest end of the spec, but should be fine unless it drops below that. Taking 10 seconds to build 60psi is a bit long, it might not be a bad idea to check the fuel filter for a restriction before going too much farther.

 

I was wondering about the filter but since I only had about 4k miles on it I figured it was probably ok. I agree though that b/c it taking so long to build maybe it got some trash in it or something. I'll check at out. Thanks. Also what about the fpr, egr, or map sensor or something. Could one of those be causing this erratic behavior?

 

So here is something interesting. I went out to start a blazer just to see what it would do this morning. I had everything back together last night and had it running. Not great and consistent but running. I took out the mass airflow sensor morning and just blew it off with low pressure air. It looked good. Just some fine dust. And then I went to turn the key on and I get no noise at all from the fuel pump. No pressure or anything. If I try to start it the motor turns over just fine but no start...obviously. Used the jumper wire to the fuse box and still nothing from the fuel pump. It worked fine last night when I stopped working on it.I'm starting to think I have ghost in the machine.:-\