Checked the coil and have spark. I then tried adding some gas to the throttle body and it started right up so it looks like a fuel issue. I can hear my fuel pump clicking on likwhen I turn the key, would it still turn onand not function if its bad?

I am going to pull the furl filter to see if its clogged. Any other ideas?

Thanks!

 

Definitely a fuel delivery issue. Replacing the fuel filter is not a bad idea. Next step is check fuel pressure and leakdown. Most auto parts stores rent/loan fuel pressure testers, and sell them for around $40. When you have one available, let us know and we can walk you through the tests.

 

I looked into how to do a leakdown test and I don't think I have the necessary tools or knowledge to perform one myself. Should I look into having a shop perform one for me?

Other than a leakdown test is there anything else I can test? When I turn my key I can hear the fuel pump turn on.

My plan is to remove the fuel filter, turn the key on and see if any gas pumps trough the line, if it's hitting the fuel filter that should tell me if the pump is bad or not, right? I figure I need a new fuel filter either way so I am going to throw one on today.

If it's going through the filter then it's either not hitting the injectors or not priming, right? I spent a few hours reading some old threads on here and I am not 100% sure it's the fuel pump.

 

Cant do a "lets see if its working" test on this and call it good. These blazers have to have at least 58-60 psi. That means if its pumping 45psi,its not going to work although it looks good.
If you plan on doing this yourself,cool. its easy breezy. plumb up the tester and turn the key on. Its gotta hit 60psi. then hold above 55 for 10 minutes. If its any less,pumps likely bad. If you dont think your up to the task,take it over to a shop and ask them to test it for you. tell them you want the numbers at key on,and after it sits for 10 min. I doubt they will charge as they will hope to get you in the doors for a pump replacement. If you do want them to do the pump tell them you ONLY WANT ac delco pump installed. nothing else. Its gonna cost a bit more,but 99.9% of the time they are good out of the box,unlike half of the cheap pumps ive installed worked for 2 weeks,or were dead on arrival. im done with cheap pumps,thats just my experience and many others on the blazer forums.

 

I was mixing up the fuel pressure and leakdown tests, so I was a bit confused at first. I can do the fuel pressure test myself, but the leakdown might be a challenge. I am heading to AutoZone right now to rent the tool to test the fuel pressure.

Can I test the fuel pressure without actually starting the truck? I just turn the key to on once I hook it up and it will still work?

Should I do this test before or after I put a new fuel filter in?

 

I just found someone who will do a leakdown test for free, one of my friends dad is a retired mechanic and will check it out later this week for me. I just got the fuel pressure tester and filter, going to finish up some work inside then head out and get to work on the blazer.

 

If you have the fuel pressure tester you can do the leak down test yourself. All it is is seeing if you hold the pressure (around 55) after about 10 minutes of having the key off. So if you get 60 on prime then turn the key off and see where it's at after 10 min if it's lower than 55 give or take you have a leak somewhere in the fuel system.

Edit: I also wouldn't change the filter until you've done the pressure/leak down test. You could potentially create a second pressure leak and make it even harder to diagnose. That's just my logic tho some will disagree.

 

I ended up not being able to do the pressure test yesterday I got called back into work for a few hours last night. I am off work again in a few hours and I am going to do the test.

If I see anything less than 55psi, what would be the next step, should I drop the tank and throw a new fuel pump in, or should I check the fuel line for any leaks or what exactly?

I did a quick visual inspection on the gas line and it looked fine, but I will look more closely today. I have the fuel filter ready to go too if and when I do the fuel pump. I have a feeling it's the pump from what I read it's a common issue.

 

Pressure must be 60psi to 66psi when the pump is running and the engine is off. It must remain above 55psi for at least 10 minutes after the pump shuts off. Post your results. If it passes both tests, we'll move on to the next step. If it fails one or both tests, there's a problem and further testing is necessary to pinpoint it.

 

Sorry for the delayed response, I ended up getting it all fixed yesterday. I was getting 9psi with the pressure tester so I decided to just drop the tank and throw in a new pump and filter and it's back to running condition. Thanks for all your help guys!