So I drive a 4dr 1997 Chevrolet Blazer LS

I installed a new fuel pump today because I needed a new one. But now the Blazer will not start. It cranks just fine though. And there is pressure going to the engine but I'm not sure exactly how much Psi it is. The odd thing is that when carb cleaner is sprayed into throttle body it starts up fine and runs fine. I'm lost any ideas???

 

You're probably going to have to do a fuel leakdown test. Get the loaner fuel pressure gauge from an auto parts store. This link tells you how to completely diagnose your fuel system. https://blazerforum.com/forum/tech-a...agnosis-23038/

Also, if you put "fuel leakdown test" in the search box, you'll find a few hundred threads discussing this that sum up basically what the link talks about.

Look for posts from Captain Hook or swartlkk and quite a few other very helpful experts.

 

I got a fuel pressure gauge and did the test.

With the ignition on and the engine off the fuel pressure shoots up to about 50psi then drop to zero before the fuel pump even turns off. When attempting to start the Blazer the fuel pressure is about 30psi and the Blazer crank but it won't start. If carb cleaner is sprayed in the throttle body the Blazer starts right up and the fuel pressure is 50psi, and it runs fine.

So whats the problem now?

 

Junk pump, replace it. Also did you change the fuel filter?

 

bad pump. ive learned you gotta go oem on pumps

 

What made you replace the pump in the first place? Was it not starting or having other symptoms?

 

I have replaced the filter in the past couple of months and I was replacing the first pump because it wasn't even engaging when I turned the key. I should note that I was originally going to sell the Blazer so I purchased a cheap pump from Amazon. I now know that it was my best decision. So I will be going to the auto part store today and buying a "good" pump. Now is Airtex a reliable brand or should I just break the bank and go for AC Delco?

 

You HAVE to go ac delco or delphi (both oem pumps). You're basic auto stores usually only carries aftermarkets. You'll have to either go to the dealership or buy online. I can help you find it alot more reasonable online. Do you have the 2 or 4 door?


edit

DELPHI Part # FG0072 (for 2 door)
DELPHI Part # FG0071 (for 4 door)

ACDELCO Part # MU1772 (2 door)
ACDELCO Part # MU1755 (4 door)


google the part numbers and find the best deal. i was looking online they are around 225+ shipping. rockauto is where i get my stuff if i cant get it locally,plus they have a 5% off code on this forum.

 

Alright thanks for the help guys

 

I will defer to Chris's experience as far as what brand of pump you should go with. However, I would still continue on with the steps to insure there is not something else that is bad. Here is a quote from Captain Hook (the thread is in the link below the quote):

"The next step in diagnosis is to adapt the fuel pressure tester so it will connect directly to the outlet of the fuel filter. All fuel pressure and flow must "dead end" at the tester. When the pump is running, pressure must be 73psi to 108psi and must remain above 55psi for at least 10 minutes after the pump shuts off. It either part of the test fails, make sure the pump module is getting battery voltage, (grey wire) and resistance to ground, (black wire) is less than 5 ohms at the module connector. If those both check OK, the pump needs replacement."

https://blazerforum.com/forum/2nd-ge...d-75428/page3/