I have a 2001 Chevy trailblazer and I was in line at a drive thru and it just out of the blue died and it will start back every time but it runs really rough and it backfires out the exhaust pipe I bought a fuel filter to put on but someone told me it probably wasn't that .. I just had a new fuel pump out in it could I need another one???? Could this be electrical?? Please help I have owned this truck for a year now and I have driven it like 3 months I have spent 2000 dollars tryn to fix the problem and it hasn't fixed it

 

This definitely sounds like you could have a fuel supply problem. Do you have access to a fuel pressure tester? If not, you may want to see if your local parts store allows renting of one. Once you get one, test the fuel pressure per THIS THREAD and post your results. That will tell you if you have a fuel system problem.

 

Thanks!!will do that... I think I can get my hands on one of those

 

What else did you replace? Have you done a tune up (cap, rotor, plugs, & wires)?

 

Ok we tested the fuel pressure and it said 60-63 when u just turn over the key and with it running it was about 58-59?? People are telling me that is a normal read?? What is normal?
Yes I have done cap and button and I just priced it for plugs and wires today cause I have knifes how long it is has been since that was done and the feller who tested the fuel pressure today said it sound like maybe it has a dead plug?? Possibly??
So should I changed those before moving on or no??
By the way thanks so much for tryn to help me solve this issue its gettin cold out and the car I am currently driving has no heat and that isn't gonna fly with 3 children!! So again thanks for helping me!!!

 

60-63 is ok. Running doesn't really matter.

Did you test leak down (pressure hold after the pump shuts off)?

If the plugs & wires haven't been done, I would definitely get that done. The #3 plug can be a pain, but there are some tips in the Tech Article section to help you out. With the wires, replace them one at a time and be sure to use some dielectric grease in the boots at both the plug & the cap. When you slide the terminal onto the cap, use a small screw driver or tiny straw to release the air from inside the boot as it is slid on. I have seen air pressure in the boot push them off of the cap terminal when the engine heats up.

What brand cap & rotor did you use? Many of the chain store aftermarket parts are known around here for being sub-par and can often cause the problems you were attempting to remedy by installing them. More than one member has chased ignition problems that way. AC Delco or Delphi for the cap & rotor as well as the plugs in my book. These ignition systems are finicky.