1998 z71 will start and not start

[just1news6]

SO I have a 1998 z71 with 289k all original drivetrain miles and it has been fine until now. Sometimes it will crank up and run fine, other times it will crank and run for a second then die, and sometimes it will not crank at all. It was throwing a po304 cylinder 4 misfire and a po300 multi cylinder misfire code, sometimes it runs rough when you crank it up, but typically when its warmed up it runs super smooth, I replaced the fuel filter and it was really dirty. When it does not crank you can tap on the fuel tank and it will start, so im thinking it is the fuel pump, I just wanted some other opinions before I throw down the dinero

[kahjdh]

Yea pump, prob due. Make sure you clean tank good before you open it to keep crap out.

[j cAT]

Originally Posted by just1news6

SO I have a 1998 z71 with 289k all original drivetrain miles and it has been fine until now. Sometimes it will crank up and run fine, other times it will crank and run for a second then die, and sometimes it will not crank at all. It was throwing a po304 cylinder 4 misfire and a po300 multi cylinder misfire code, sometimes it runs rough when you crank it up, but typically when its warmed up it runs super smooth, I replaced the fuel filter and it was really dirty. When it does not crank you can tap on the fuel tank and it will start, so im thinking it is the fuel pump, I just wanted some other opinions before I throw down the dinero

since the fuel filter was very restricted , after you replace the fuel pump and, test for proper pressures , replace the fuel filter again, after a few thousand miles to be sure you do not still have more restrictions , which will stress out the pump. keep fuel above 1/4 at all times. this is how these pumps fail early. use the delphi fuel pump. DO NOT USE AIRTEX as many have had failures after a few months.

[just1news6]

Do you all suggest getting a rebuild kit or a complete new assembly?

[j cAT]

Originally Posted by just1news6

Do you all suggest getting a rebuild kit or a complete new assembly?

the delphi pump will come complete .

did you check for fuel pressure ? DID IT HOLD THE PRESSURE on engine off for 15 minutes , to with in a few psi ? need 60-65 psi.

[777stickman]

Originally Posted by just1news6

Do you all suggest getting a rebuild kit or a complete new assembly?

Also make sure the new Delphi pump is specific for your VIN!!

[just1news6]

How do I find out the correct one where in the vin would it state which pump I needed???? Its a short bed extended cab 350 5.7 vortec

[j cAT]

Originally Posted by just1news6

How do I find out the correct one where in the vin would it state which pump I needed???? Its a short bed extended cab 350 5.7 vortec

just give your vehicle infomation and you will receive the correct pump. they made some pump assy different depending on the emissions regulations . the vin will give the part supplier the necessary info to ensure you get the correct pump.

using the vin is normally used to ensure any componets replaced are correct .